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Tenny

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Everything posted by Tenny

  1. Hello Moses: Since the bore measurements were over the normal limits probably due to already being honed,I decided to send it to a engine shop that I've had good luck with in the past. I didn't think I had enough to work with at home to true the bores and still have proper piston clearance and figured it would end up at the engine shop anyways to get it right. I explained to them what my concerns were after inspecting it and they said they would just hone it if possible but agreed it would most likely have to be bored over(as little as possible). I asked them to check the crank and I also gave them the head to check and service as needed.It should be a reliable little engine when I get it back.I look forward to putting it back together right this time. I didn't want to get so involved in this engine but decided cutting corners with my fingers crossed was causing me a lot of work and money. Sometimes you just have to bite the bullet and spend more money to get a good outcome.I'm hoping when the engine goes back in it will be right at last and someone will get a good Jeep.I've learned a lot about spending some time and money up front when dealing with a used motor that you know nothing about. I'll report back when when I can get back on this project. Thanks for all your input and help. Tenny
  2. Back again for a update Moses. Even though I knew I'd be removing the head, I did get the borescope and checked into each cylinder bore before taking off the head. I didn't see much carbon build up but could see some scuffing on the cylinder walls.I could also see some cross hatch left but not where the scuffing took place. All in all the borescope will be a handy tool to have for future issues. Once the head was off, I confirmed what I saw with the scope. Not much carbon but plenty of scuffing on all bores.Much like the earlier posts from Wayne who had almost identical symptoms, I could duplicate a knocking noise by moving the top of the piston side to side near the top of the bore( aprox. .0010" of side movement). Then I removed the oil pan again and could now slide a .003" feeler gauge between the skirt and the bottom of the bore.Much easier to do now that the engine was out and upside down. I then used platigage to check the rod bearings for clearance.All have .0015 clearance except # 2.It has only .001. I noticed rod bearing shells # 1 & 2 have a .001 stamped on the back with the 3 & 4 shells having std on them. Now I know why the bearings looked like new, they were. I assume the PO was in there trying to correct this knock along with installing a new timing chain and gear set because they also looked new.At least the crank looks good. Once I removed the pistons I could see the full extent of scuffing on them and the bore walls.As bad as the walls look, I can't feel the scuffing marks with my finger nail. I now attempted to measure the amount of wear even though I haven't got a proper bore gauge yet. I've ordered one but it's a week away. I used a telescoping ID gauge to get a idea if a over bore is called for and I'm afraid it is. After 2 hrs. of measuring and remeasuring it seems I'm outside the acceptable limits. All 4 bores measure 3.878 down 3/4" from top. Then measuring down in the bore 2-1/2", the #'s 2, 3 & 4 measurement increases .001 to 3.879 but # 1 is only 3.876. Once again I wonder if the PO honed and installed new rings on the old pistons which would account for some remaining cross hatch and great compression. I also can't explain why # 4 has 175 psi cranking compression.I'm going to try another gauge once the engine is running again.A bad gauge is the most likely culprit. The bores do seem to net the same results when I measure across them in line with the crank so they do appear to be round.Once again, even after much remeasuring to get consistent numbers, I'd be more confident if I had a true bore gauge if it's the difference of a overbore or just a hone job. Then I looked at and measured the pistons.Once again I wished for the proper tool(bigger mic) but had to use my oversized dial calipers instead. I can't find these special tools around here with out ordering them. I took 3 measurements on each piston. 1 at the very bottom across the skirts (A). 1 across the middle at the center line of the pin (B) and the last 1/4" below the bottom ring(C). Measurement A(across skirt) is 3.872 on all 4 pistons. Measurement B( across middle) is 3.874 on all four. Measurement C(just under rings) is 3.870 on #2 & #4 and 3.869 on #! and 3.868 on #3. Not sure what new pistons would measure but this seems a bit undersized as indicated by the rocking type wear and scuff marks. Probably the source of the knocking wouldn't you think. I've added a few pictures of the worst worn areas including a view of the head.I noticed intake valves on #'s 3 & 4 are darker colored then the others.This is both sides of the # 3 piston which is the worst but the others aren't much better. The top of the #4 piston(175 psi comp.) was this clean when I took off the head. It may be that I'd been testing for the knock source with the engine running by removing the plug wires on these two cylinders as well as unpluging the injectors just before shutting it down. If my bore measurements are correct and bores are already honed oversize, I'm most likely looking at a bore job.Would you agree or are slightly oversized pistons available to correct my problem ? In the meantime I'll move onto another project until proper measuring tools arrive. Thanks again: Tenny
  3. Hello again Moses I finally got my new camshaft,lifters and timing set and distributor installed and much to my disappointment the knock hasn't changed.I held out hope while the engine was at fast idle for 20 mins. breaking in the cam but as soon as it was brought back to normal idle the knock was still there. I did some more testing and am quite sure it is coming from a piston.I once again removed plug wires 1 @ a time and it did seem like # 4 made a little less knock.If I reved the engine quickly the knock would subside some but when I let it return to idle it would make the clatter until the engine slowed which is what I hear when engine braking while driving. I also unpluged 1 injector @ a time and got the same results, a little less knock but not gone.I did do a static comp. test on the engine warm this time and had 160 psi on #'s 1 & 2.On # 3 I had 150 and # 4 @ 175.Interesting the suspect problem cylinder has the most psi. Maybe a lot of carbon ? I'll find out tonight. Even though I thought everything looked good on the bottom something isn't. So now the little engine is back out and on a stand waiting to be disassembled.I would like to do a pressure leak down if I can get a tester in time.The borescope I ordered did come in and I'm going to use it tonight.I want to get to the bottom of the noise but I'm not disappointed that I had to remove the engine.It did have a bad rear main seal leak that didn't show it self until ran for a while. As far as the running part of the engine with the new camshaft and parts, it runs great but it always did.It does have a better idle now. Before it would have a slight uneven idle once in a while. Maybe the bad dist.? At least I know it will continue to for a long while to come when I'm done. I'll update once I get into it. Thanks for your help.Tenny
  4. Hello again Moses: The oil flush I used was Liqui Molly pro line engine flush.It has great rating's and cost more then most so it must be good.The oil in the engine at first was 10W 30. After 250 easy back road miles,(probably 8 hrs run time) I figured the knock wasn't going away on it's own.I drained 1 qt. of hot oil from the engine and added the flush. I followed the instructions (start and idle engine for 15-20 mins then change oil and filter) After filling and installing a new oil filter, I filled the engine with diesel Rotella 15W 40 oil because I read it still has zinc in it for flat tappet lifters(is this a good idea ?).I also added 4 oz of Marvel mystery oil. Before starting it back up I pulled off the coil wire and cranked the starter a few times until I had oil pressure.I then started it and after about 30 sec. it still had the knock but seemed to be louder now. It could have been the natural worsening of what ever is causing the knock since it had some added run time. Hard to be sure. I do know the entire inside of the engine is now spotless and the valve train free of any sludge. When I drained and dropped the oil pan to check the piston skirts, I did notice about a 1/2 tea spoon full of black,crunchy carbon deposits +/- the size of a pencil tip in the bottom of the pan.I ran a magnet in the drained oil and pan but didn't get any thing on it so I know there wasn't any steel nor was there anything shinny.The deposits could be crunched between my thumb and finger leaving a black smudge so I don't think they were the chain tensioner ether. I thought the oil flush or running Seafoam through the throttle body may have cleaned these deposits from the internals.There was also some in the drain pan as well when I dumped it. I cut open the first oil filter(the one w/250 miles on it) and found no metal or debris in it. Oil pressure has always remained steady around 50+ psi. even @ hot idle. I haven't had any CEL's and did scan for codes but have none present at this time. While the Jeep was running and knocking, I've removed the plug wires one at a time (twice) and it didn't affect the knock.Would this rule out a injector, carbon build up or other spark/ fuel knock issue? I am going to use this problem as an excuse to get a borescope. It would be helpful in many projects I get involved with. If good lifters are slightly convex then my old lifters do have some wear since they do have a slight concave(dish) shaped base.I believe since all of the cam lobe bases were shinny only on the rear 1/3 portion, the lifters have been worn this way for a while.If they were convex it seems the would have shined up the middle of the lobes, not just the edge. As I mentioned earlier,the old distributor I removed had about 1/16" of side movement at the rotor end but none at the gear end.I plan to remove the shaft from the housing and gear from the shaft to use it in a drill to prime the engine with oil before starting with the new cam and parts. When I ran the engine without the rocker cover trying to locate the knock, I did notice 4 push rods spun very fast and 4 much slower.They would be the 4 with the non tapered wear on the high point of the lobes. I did have lots of oil quickly coming up to the rockers. Also putting pressure on 1 rocker at a time didn't affect the knock ether. These are all just thoughts and observations to keep me busy while I wait and wonder until the new parts arrive. Until that time: Tenny
  5. Thanks for all the input on my engine knock Moses.To be more clear on a couple of points, the cam measurements I took where done as follows: I mic'ed the lobes on the sides to get the base size(all were the same and correct) then from highest point to opposing side(base) to get amount of lift and compared the measurement to the advertised specs of a OEM cam lift .This is where I observed the lack of lift on all lobes,all to much but some twice as much as others. Then I mic'ed the 4 cam bearings.The surfaces looked wear free as did the cam bearings in the block.The rear one was 2.00" and they increase in dia. .010" per bearing to the front one on the cam which measured 2.030". I've never replaced a camshaft before but thought this made since for removal/installation reasons ??? Then I put V-blocks under the end cam bearings with a .015" shim(half the total difference in their dia.) under the small end V-block to bring the cam center line up even with the .030 larger front bearing. Then with a dial indicator I first checked the base of each lobe and they where all the same showing no wear. They also have what I think is the correct .001 taper(bigger at the rear of each lobe base)which under normal circumstances would help keep the cam towards the rear.They taper is evident on each lobe base as only the rear 1/3 width of each base is shinny with the front 2/3 showing brownish oil color. It's only at the max lift point of each lobe where things get ugly.I even took a file to the worn tip of the worst lobe since I wouldn't be reusing it to see if the case hardened surface had been worn through.It still seemed to be present but must be very thin. The lifters actually looked and seemed to test OK although I'm replacing them of course.After pulling them from the engine which hadn't been run for 2 days, I couldn't compress any of them.They do have a slight concave base of less then .001" and measure the same height as well looking shinny and pit free. The knocking noise I could recreate was by prying the cam rearward.It only moves about 3/16" front to back so I'm sure it not hitting the rear plug.The noise is when the back side of the cam gear hits the block with a little force,more then it should while running in normal conditions.I'm hoping the sudden back and forth motion of the cam that I observed while rotating the crank is causing this abnormal front to back force, enough to cause a knock.??? I am replacing the snubber and tensioner even though the ones I removed show very little wear.The chain needed about 1/2 of the tensioner's total travel to keep it tight and the snubber has hardly been touched. The cam gears do look a little sharper at the points then I've seen on other engines but will know better when I can compare them to the new cloyes set coming. It is strange how the engine went from "no bad noises" for the first few start ups then to a slight knock only at idle that went away when warmed up to where it is now. It did seem to be worse after using a quality engine oil flush as directed and then changing the oil and filter to Rotella T-5 15W-40. I've read others have had some success doing this but not me.I also used seafoam in the gas and through the throttle body as directed but noticed no change.Runs real good though. It always had the rattle/clatter when letting off the throttle going downhill. It reminds me of a rattle that a little 48 CJ-2A had that I used to have when pushing the clutch on it to shift but I knew it had a bad throw out bearing.My noise now is from the engine and goes back to the knock when I push the clutch, allowing the engine to idle. It's possible the two different noises are two different reasons. If the engine still knocks after the cam,lifters,chain,gears and distributor replacement, I'll spend more time checking for other causes.If nothing is found then I'll remove the engine and hone it, install new pistons and anything else that doesn't look right. This little Jeep was a worthy project that needed saving.It looks and drives real good and I plan to sell it so the noise has got to be found at all costs. I'll get back with results after the cam install as soon as it gets here. Thanks again: Tenny
  6. I haven't had much interest in this topic yet but I thought I'd go ahead with a update anyways. Since I found no reason for the knocking I was hear from the crank related parts of my engine, I decided to remove the camshaft and try to figure out what is causing it to move back and forth when rotating the crank from below.I couldn't believe this is normal. The lifters look and test fine but the cam doesn't look so good.I work in a machine shop so can accurately measure for wear of the lobes.according to the specs of a OEM camshaft,I found that 3 of the lobes are worn to the point that they've lost .022 " of lift and the rest between that and .012 ". I also think I found the reason the cam was walking back and forth while rotating. 2 lobes(#8 & 6)are worn opposite of the way they should be with a .001" taper that would force the cam forward against the button inside the cover.This shows to be the case because both the cam gear bolt and button inside the timing cover show wear. Then the front 2 lobes(#1 & 2) are worn but still maintain a .001" taper" that would force the cam back to the rear.I read that all the lobes are ground with a .001" taper to keep the camshaft in place. Does anyone know if this is true? It makes sense from the measurements I took at the lobe bases where there isn't any wearing.Each lobe has a .001" taper front to rear (bigger @ the rear) which would cause the lifters to spin and gently encourage the cam to run back where the gear contacts the block acting as a thrust washer. All the other(4) lobes are worn flat with no taper at all just holding the cam neutral. When looking at the cam and the position of these tapered lobes, it makes since that the cam would walk back and forth while turning under the pressure of the valve springs, which would be greatest when the lobe pushes the lifter up. As the cam turns, starting @ TDC.# 8 lobe pushes the cam forward.Shortly after,the next lobe to push a lifter up is # 6 lobe which is also the lobe with the wrong taper. Then all of the 4 other lobes to push lifters up in sequence are the ones that are just worn flat, not causing the cam to move front or back.Then when the cam reaches 180 degrees of it's rotation,along comes #1 and a few degrees later # 2 lobes pushing their lifters up(having the proper taper) forcing the cam rearward back against the block where it should be.I believe(and surely hope) this is the knock I could hear when the engine was running.As I'd mention in my first post, I can get a similar knock when prying the cam rearward when it was still in the engine. I do have a new camshaft and lifters ordered with a complete timing chain/gear set.I already have new rockers and push rods.Even if this cam swap doesn't cure the knock problem,it needed replacing anyways.I'm blaming the use of zinc free oil for the last half of the Jeeps life for causing the camshaft wear on an other wise good engine. I'm posting all of this as my "theory" now to convince myself it is my knock problem and will update the actual results once I get the engine running again.I haven't seen any other situations where a worn camshaft was the culprit of a engine knock so I remain skeptical. I'm still looking for any info,advice or feedback from anyone that has thoughts and knowledge of the problem of knocking Jeeps. Thank:Tenny
  7. Hi Moses: I've researched dozens of these knocking, rattling and ticking Jeep engine cases but after checking mine for similar problems/fixes I haven't found a viable cause to repair. I started the restoration of a 2000 TJ SE with a blown 2.5(threw a rod out the oil pan).I took on the project after finding a "good" 2.5 with complete running gear from another TJ with rusted frame, no tub.The gentleman I bought it from claimed it ran good with 80k but the frame rust was no longer repairable so he put the tub on another TJ w/4.0 and a rusty tub. Before installing the good engine, I checked static, cold compression which was 175 psi +/- 10 lbs. I thought this to be good since the engine had not run for over a year. Everything I checked or replace on the engine indicated it was a sound engine w/ 80k. Once installed in the now restored Jeep,it started right up but had a bad skip on at least 1 cylinder. I was just about to remove 1 plug wire at a time but the skip went away and it ran good w/ a constant 50+ psi oil pressure hot or cold.I figured maybe a stuck injector or just air in the fuel system caused the skip for the first couple minutes. I didn't hear any noticeable ticks or knocks for the first several times I started and ran it but when I was about ready to take it out for the first test drive,I noticed a slight knock had developed @ idle only.As soon as I cracked the throttle it went away but came right back @ idle.It was also very present going down hill using the engine to hold me back(5 spd) but was very quiet at idle once warmed up. I continued to drive the Jeep for 250 back road miles but the knocking got louder @ idle and didn't quiet down as much once up to temp and it still rattles under compression braking I've tried some of the suggested fixes including sea foam and marvel mystery in oil.I also used a good oil flush as directed and changed the oil to a thicker Rotella T-5 (15w-40) oil.It seemed like that only made things worse.Now it sounds real good and quiet at cold start but begins to knock within 20-30 seconds. I used a stethascope and listened all over, under and around the engine, including the dist.,timing chain cover and oil pan.I thought the noise was loudest under the valve cover but also on shallow end of pan.I thought no oil on that end might account for that.Just listening to it run with the hood up made me think it was a top end valve lifter/rocker issue. I removed the valve cover and everything looked good and tight cold.Then I fired it up and ran it til it started knocking and shut it down for a recheck.Everything still looked good and tight and then with the engine was running and knocking, I put pressure on each rocker which made no difference to the knock.There is plenty of oil coming up the push rods and they all spin while the engine is running although a few spin slower then others. I'd already bought new the rockers and push rods hoping that was the problem so I replaced them.Of course that didn't help. I then removed the oil pan thinking I'd find a loose piston skirt to bore situation but I couldn't get a .002 feeler in while holding the piston to one side all the way down in the bore on any of them.If one slapped I think they all would since they are all the same and that's not the noise I hear I removed the rod bearings to inspect and they look new, perfect and tight. I checked for piston pin wear while the bearings where out and everything is tight.I have no excessive or noticeable crank end play. After removing the timing chain cover,I saw the chain is tight with the adjuster that shows little wear. The only things I've found is I do need a new distributor as mine has some gear wear and a lot of side play at the rotor end.The gear on the cam looks fine though. Also I removed the plugs to make turning the engine from under easier and I noticed the cam will move forward and rearward(end play) aprox 3/16" a couple times with every revolution of the crank. After removing the chain cover I can see that the thrust button on it is shinny as is the center of the cam gear retaining bolt.While turning the engine with the cover off, I can hold the cam from coming forward with my hand with out much pressure. I was sure the end play on the cam would be my problem but everything else looks normal. So to recap my symptoms: (1) Engine is quiet on start up but knocks within 20-30 seconds. (2) knocking increases with engine RPM's but unsure if 1/2 speed(cam related) or 1 to 1 with RPM(crank related).Going to check that when I get it running again. continues to knock but not as load after warm up. (3) Rattles while going down hill, engine braking (4) Removed 1 plug wire at a time while running doesn't effect knock. (5) Engines runs and starts perfect at all times with great oil pressure and normal coolant temp. (6) I am running regular gas but it just doesn't sound like spark knock plus it increases with RPM while going downhill, foot off the throttle. Once I get it going again I will shut the engine off going down hill with the clutch out in gear to see if it knocks then.Not sure what that would tell me but just curious. I still have the engine apart hoping to find something but will put it together for more testing up top,(lifters) if need be.Also I'll install a new dist. after I've started it to see if it still knock.I'm sure it will. The one thing that I'm uncertain about is how the cam walks forward to the thrust button then back as I turn it over.It does make a knocking sound when I pry it rearward all the way with pressure. Does this sound normal? Thanks for enduring this read.I've been about 3 weeks trying different things and collecting as much info as I could before asking for help. Tenny
  8. I'm curious to drive this Cherokee and see how it handles the hilly roads we have around here.I'm hoping the light weight is enough to allow the little engine to not feel totally gutless but to be honest I'm not expecting much so I won't be to disappointed.It's just going to be a summer toy anyways.I did find a tag on the rear axle with 3.54 on it.Does this make sense? I thought it was strange because until now I didn't realize only the manuals came with 4.10. The PO did put a nice 2" spring lift and 30" tires on so not having overdrive is a good thing.I wished I did have the 4.10 axles and if it's too much of a dog I'll take out the lift springs and put smaller tires on.I hate to go to that expense and it does look nice lifted a little. I've driven the older CJ 5's and YJ's with the 4 banger and thought they were OK but they had the low gears and manual trans.I like putting turbo's on rigs that were built to early to have one and have toyed with the idea of doing it to the Cherokee but only as a last resort.Someone drove it 70k miles the way it is so it must not be un-driveable.We'll see and I'll keep you posted.
  9. OK,the new(used)charcoal canister is in and it works great.Now I only have vacuum to the EGR valve when the engine is warmed up and I open the throttle as it should.Also the EGR no longer makes a flutter noise when I let off the throttle. I cut my old one open to see what was wrong with it and at least the foam filters were still intact keeping the charcoal from being sucked out.Then I popped the cap off that has the EGR line port and the little diaphragm did have a cut in it which would cause the vacuum issue I had .If I could have found that diaphragm I could have fixed my old canister easy.Also if leaking charcoal was the only problem, a person could replace the foam filters and glue the canister back together since it is hard to find a good one.Just thinking it could be an option for someone. On to the painting part of this Pioneer project.When it's done and I can drive it more I'm sure I'll be back with more issues, hopefully little ones. Thanks for your help, it's been a learning experience working my way through these problems. TJ
  10. Another quick update on my quacking EGR valve.Now that we've had some spring weather I've been sidetracked with other projects but think I've found the problem. I found I have a constant 12-14" of vac in the line going to the EGR valve.I ran a line directly from the EGR solenoid to the EGR valve, bypassing the charcoal canister and it(EGR) works as it should with out noise.I'm assuming there is a diaphragm inside that has a leak? I bought another used canister off Ebay since I couldn't find a new replacement although I feared it wouldn't be any better then the one I had.It did come with a guarantee that it was tested and worked but I had to return it when I could shake charcoal bits out of the vac ports. The seller is living up to his word and sending me another so I'm now waiting for it to arrive but don't dare to get my hopes up that it will be OK. Do you know of a new replacement that will work if I need to go that route.I did find one at Summit for a mid 80's Nissan that looks about right but not sure of the inner workings. I'll post back with my progress when there is some. Thanks for all your help.
  11. It's been a week of testing and tinkering on my 86 XJ when ever I could find some time so I thought I'd give an update on what I've found. Although it seems to run well, maybe even perfect, I was annoyed that it would have to stall once after starting warm or cold and be restarted before the ISA would open the throttle to maintain a good idle.After cleaning all grounds, testing all sensors, including the power steering pressure switch that my 2.5L does have, I was convinced my issued lied elsewhere.I rechecked all vacuum lines changing any that were questionable.I removed the ECU and cleaned the terminals as you suggested and was sure this was the problem since a couple did have grey corrosion on them.I was hoping for a good startup but it stalled as it had always done, needing to be restarted.I haven't checked my fuel pressure yet because I can't get the test port plug out.Although I want to check the fuel pressure at some point, I will have to remove the throttle body to do it but not right now since it runs well except for the start up problem.I really didn't think this was the reason why the ISA wasn't opening the throttle when the engine was started but more likely an electrical issue so I didn't want to open up a throttle body can of worms. After a lot of looking around under the hood for wiring problems and fixing anything that looked dicey, I noticed an empty connector for a relay next to the fuel pump relay.I figured this was for an AC relay that wasn't needed since I don't have AC.After more fishing around about this empty relay block I found it's called a "Power System Relay" and it delays the power being turned off to the ISA when the engine is shut off for a few seconds.This few seconds of power is enough time for the ECU to extend the ISA, opening the throttle for the next start up.Now I know when the ISA is supposed to extend and mine wasn't. I was hopeful but couldn't believe the fix could be so easy.I got the relay which turns out to be the same as the fuel pump relay and bingo-it made the ISA work as it should.I can't imagine why the PO removed this relay unless it was needed for the fuel pump some time years ago.I was so relieved I really didn't care. Now when I fire the engine up hot or cold, it idles perfect on the first start up.I'm glad I went through all the systems as you suggested on the way to finding this relay fix. Many things were in need of cleaning, tightening and adjustment giving me a better running, more dependable Jeep in the future. New problems that arise down the road will be easier to fix now,I hope .Plus when the ECU was replaced in 2012, the PO only put the 1 easy bolt back in leaving out the other 2 hard ones. This was causing a under dash rattle that I couldn't find until now. I do plan to remove and clean the throttle body and injector in the future.I'll also get the frozen test port plug out but want to get it on the road and drive it first to find any other issues. As for my new EGR valve, although it seems to function OK at idle and when opening the throttle quickly, it does make a fluttering and quacking noise, mainly when I let off the throttle.If I hold the throttle around 1500 rpm the EGR diaphragm will vibrate and cause a vac flutter and the engine to run a little uneven as well but when I throttle up past 1500 it will smooth out and run good.The engine doesn't do this if I disconnect the line at the EGR.The vac flickers up and down quickly a couple of inches at idle with or with out the EGR but not when I throttle up with out the EGR, only with it.Do you think I might have a bad EGR valve even though it's new? I got a standard brand which came with 3 washers and a chart instructing me which one to put in according to my old EGR part number.It called for the #10 washer which is consistent with what I've read about others doing. I also rechecked the base timing with a test light and it does show 12 degrees BTDC now.Ether all my tweakings have corrected this from the 18ish I saw earlier or I just misread it before but I like the proper 12 now. So now that my little Pioneer runs and yard drives well it's time to switch my efforts to making it look good. Thanks for the education and help. TJ
  12. Thanks for pointing out more trouble spots to look for.I'd planed to check the CPS signal as well as the O2 sensor but forgot.I didn't check fuel pressure before replacing the fuel pump because I had it out repairing the sending unit that lost ground due to loose a connection.I also replaced the tank straps and hoses and didn't want to drop the tank again if the old pump failed even though I think it was OK.Turning the key on and off, cycling the pump before starting hasn't had any effect on my stalling issue before or after repairs but will do the pressure checks to be sure it's correct. Before replacing the EGR valve I checked to be sure the EGR control solenoid was functioning correctly and it was.I have 20-21 in. of vac @ the switch input line and can hear and feel the EGR working when reving the engine from under the hood.In fact when I let off the throttle I can feel the diaphragm vibrate as it closes making a slight snorting noise.I hope this isn't a sign of a crappy valve. The PO had a garage replace the ECU and do a few other repairs shortly before the Jeep was parked due to it failing our state inspection.It needed brakes, exhaust and suspension work which I have done.The distributor install not being correct among a few other quick repairs makes me question the shops knowledge of this Jeep so the grounds and ECU connections will be a good place to look. I'm not 100% sure what is the correct operation of the ISA.It works well to keep a good idle once the engine is running but when should it correct the throttle position for the conditions, while the engine is cranking or after it starts? Mine doesn't adjust until after the engine starts but not quick enough to keep it running.After it stalls once the ISA extends, opening the throttle before I crank the engine again to start and it idles good.If I bump the starter once before starting,the ISA will open the throttle and then when I start it, it will stay running.If I shut the engine off even warm and immediately restart, it will sputter along trying to stall for a second or two until the ISA has time to increase the idle and stay running. Hopefully the problem lies in one of the above checks. I'm use to working on older vehicles with mechanical linkage and adjustments but enjoy the new challenge of trouble shooting the newer sensor and electrical systems. knowing what is out of spec and causing the problem when I test it is the key.Boy there are a lot of sensors to check ! The info on this site has gone a long way in giving me the knowledge in what to look for. There is one last thing that I question.I assume once the stationary idle set screw stop in the TBI throttle bracket is set it never should never need to be adjusted again.When the engine is running the ISA adjustment bolt should maintain contact with the throttle, keeping it off the set screw stop and the correct the idle as needed.When the engine is shut off should the throttle be held off the stationary stop screw by the ISA ? If the PO adjusted the set screw stop in an attempt to correct another issue, it could through off the closed TPS adjustment.Would the correct adjustment of this stop screw be to just contact the throttle stop tang when the throttle blade is fully closed just to prevent damage to the blade? I'm going to check on this as well. Once I go through the list of checks hopefully one or more will cure my problem.I'll post again(shorter) what I find.
  13. Thanks for the reply Moses.I'll give a little(lot) more info on what I've done to my Jeep.Since it was running when I bought it 5 years ago,I drove it only a little but enough to know it was so gutless that something wasn't right.I kept good non-ethanol gas with stabilizer in it and would start it a few times a year.It always did this start stall thing but I figured a tune up and tinkering would cure the problem of low power and the stall.I also have done the key on and off a few times to cycle the pump but it made no difference. I suspected a bad pump and filter was at fault for lack of power so I removed the gas tank and put in a new pump and inline filter.I also had to run a new vapor line as the original one was rusted.At this point it still would stall once on start up then run fine. Next I did plugs,wires,cap and rotor.I also had to reposition the dist. as described in your tune up section so the hold down bolt would line up with bolt notch in dist housing when rotor is at about 6: O clock TDC.Who ever messed with it before me didn't have your guidance on how to set the base timing and the entire dist. was clocked about 90 degrees off but it still ran OK since the drive tang was also off the same amount.They must have adjusted the dist. old school with a light until they got the proper base timing even though the it wasn't in the right place. I've checked the base timing with a light now and it's at about 16 BTDC at warm idle and advances as it should with RPM's. I had to replace rotted vac hoses to the MAP and a few other key places.I poured Seafoam into the throttle body while keeping it running @ high idle to clean intake and also replaced a dead EGR valve that now functions as it should.I've checked all the sensors except the 02 which I'll do today.I was hoping the coolant sensor would prove to be bad but it tested good as did all the rest.I did have to adjust the TPS however but it has a smooth and steady sweep as the throttle is opened. The lack of power turned out to be a seized kickdown lever where it goes into the transmission.It wouldn't allow the throttle linkage to travel more then 1/3 it's way to wide open.I changed the trans fluid and filter,adjusted the bands and freed up the kickdown lever.It operates the valve plunger as it should but still isn't as free as I think it should be.You can tell when the throttle is pushing it by the pressure it takes but at least it will allow full travel of the throttle linkage now and lets the valve plunger work as it should.I think if I work it a little more with penetrating oil it will improve The way I set the ISA motor without the special tool is after the engine was fully warm,I shut it off and measured how far open the throttle was.Then I bumped the starter a few times and each time the ISA would open the throttle a little more.When I could hear the ISA ratchet mechanism click twice each time I bumped the starter, I measured how far the throttle was open and bumped the starter a couple more times to be sure the throttle measurement didn't increase any more.I figured this meant the ISA was fully extended and then I unplugged it leaving it fully extended even if I started the engine. I hitched up a digital tach meter and positioned it where it could be seen when I started the engine.I then turned the ISA adjusting bolt in some to be sure I'd stay under 3500 RPM's on my first start up.It fired right up and stayed running of course due to the high idle situation and ran up to 2800 RPM's. I shut her down and adjusted the ISA bolt out a few turns at a time, starting and shutting it down until the last tweak brought it right to 3500 RPM's after it settled in for a couple seconds to be sure.This seemed to work good as I never had to run the engine for more the a couple seconds to check the speed.When I plugged the ISA in and started the engine,it fired right up at high idle and stayed running,quickly returning to a good warm engine idle when the ISA retracted as it should. Anyways after all the tweaks and adjustments it runs and idles great but just has the stall once issue due to the ISA not opening the throttle as it turns over.It's seems that the ISA doesn't get the open signal until after the engine starts.If I bump the starter once or twice then start it,it will stay running and idle fine.I've also tried holding the key on for a second after it starts and that also gives the ISA time enough to crack the throttle open. Do you think my method of fully extending the ISA is an accurate way to get the desired 3500 RPM ? It idles great warm or cold and I can punch the gas from a idle to spin the tires(on dirt) and let right off and it won't stall.I can always hold the gas pedal down a bit when I start it like an older rig with a carburetor but I'd like it to be right. Any ideas?
  14. I've got a 86 Cherokee Pioneer 4X4 with the 2.5L TBI engine and 904 auto trans that I'm working to get back on the road.It has only 70k miles and is in good shape but hasn't been driven for the past 5 yrs. due to minor issues.I bought the Jeep to fix the issues and repaint it and this forum has been very helpful.I've gone trough all sensor checks in the 2.5L tune up section and adjusted or replaced anything that was out of spec.I now have a good running and idling 4 banger with one exception.When the engine is cold(60 degrees)it will crank over several times before starting as it should.When it starts it will usually stall or try to before the idle speed control can kick the throttle open to increase the rpm's.If it can stay running long enough the ISC brings the rpm's up after a few seconds and it idles like a dream.As it warms up the rpm's drop as they should to about 700-750 and all is well until I shut it off again.Then it will start right up and stall once due to low idle even warmed up and start and stay running the second time after the ISC has increased the idle some.I can get it to start and idle the first time hot or cold if I push the throttle a bit on start up.If I just bump the starter once without starting it and then start it the ISC has time to kick the throttle open some and it starts and idles as it should. In a nut shell the ISC is a little slow in doing it's job before the engine starts.I have adjusted the ISC and TPS as described in the tune up section and I believe they are correct.The Jeep starts and runs much better after the tuning but still has this start and stall issue.Somehow the idle speed controls needs to respond quicker as the engine is cranking in order to do it's job better but I don't know how can I get that to happen. Is there any chance the ECU will need time to right itself now that I have fixed all that was wrong with this little bugger(broken vac lines, bad EGR valve,TPS adjustment + more)I haven't been able to give it a workout yet as I'm not done with the body work. Has anyone else had this problem or got suggestions on hoe to fix it?
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