Jump to content


  • Posts

  • Joined

  • Last visited

Everything posted by Tenny

  1. 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.
  2. 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
  3. 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.
  4. 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
  5. 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.
  6. 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?
  7. 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?
  • Create New...