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  1. Today
  2. Beserkr...Sounds like the O2 sensor should be okay. Compare the TPS sensors and install the new one carefully; as you note, the position of the TPS is preset on Chrysler MPI, not adjustable like G.M. and other TPS switches once were. The increased humidity increased the intake air stream density...I'm thinking you have a lean condition when the engine is acting up. The O2 sensor and PCM compensate, so this shouldn't be confused with an ultra-lean air/fuel (A/F) ratio; A/F is carefully controlled on your engine. If the TPS calibration is not en sync with the actual throttle valve angle, you could have an issue. Another source of a lean condition (a vacuum leak, too) is a worn throttle shaft or shaft bores. Spray a fine mist of carburetor cleaner at the throttle shaft ends of the throttle body with the engine idling. Listen for a change in engine speed. This is an air leak source that can cause havoc. Rule out a throttle shaft or TB related leak before condemning the TPS and throttle valve synchronization. Tip: If you do suspect that the TPS is out of sync with the throttle valve and would like to test TPS voltage responses in a new way, take a TPS that you can sacrifice for this test and try elongating the mounting holes on the plastic TPS switch; remove the TPS's locating stub to make it possible to rotate/adjust the TPS. Play with the TPS adjustment, noting the throttle valve angle carefully, and see if you get a change in engine performance. The IAC can also create a lean condition. The fact that the engine runs better with higher humidity hints that you are "normally" running lean—or have a throttle valve not reflecting the position of the TPS. IAC would be more likely an idle issue, though it could contribute to deceleration pop, but IAC would be an unlikely source for your slight miss under load. What do the spark plugs reflect? See whether there's an indication of a lean mix. Avoiding a a trip to the burn ward, carefully remove a spark plug after a heavy pull followed by immediate ignition shut-off with the clutch pedal depressed. This is an old and often helpful diagnostic tool. Typically, the plug insulation looks very light, often tan/white on these emission MPI/EFI engines. See what turns up. Take a cell phone photo of the spark plug, we'll talk about it. Moses
  3. Yesterday
  4. Moses, I just replaced the front o2 sensor with an ntk direct fit seems to be functioning good, when I pull a vacuum line it jumps full lean and when I spray carb cleaner in the vacuum leak it goes full rich. I changed it thinking maybe it was biased one way or the other from the old head which had a Crack in it thus coating the o2 sensor with cumbusted coolant but guess it wasn't the problem. I checked the tips with obd2 graphing doing a slow sweep and no drop offs or spikes it looked nice and smooth. I have 3 tps sensors sitting around I could try, they aren't slotted so it should be easy to just change one out for another. I think I got from 14% to 75% calculated position on the sweep. I checked voltage at the connector (back probed) and I don't remember what it was but I remember it being in spec according to the service manual, maybe 1.3v to 4.3v or something like that. I could check it again when I try and swap it with one of the spare ones I have. I think they are all Mopar sensors. One more thing I noticed today we are in our monsoon season here in AZ and the humidity is at 60% this morning where as its usually at 10% or less and it seems to be running way better. Any thoughts on this? I can't imagine what would change in regards to moisture in the air that would be a positive, maybe lower combustion chamber temps? Maybe I should try running mid grade or super gas?
  5. Last week
  6. Two huge time-savers...The router and deck idea is very smart, I've done many bearings with sand drums and had to back off constantly to avoid side loading my drill press. Also, control is so much better with your flat deck and router approach! This helps maintain a precise bearing bore. Motive's backlash marking plus providing the pinion depth measurement is brilliant. If you do this carefully, the setup should be right on, a huge time saver. Then there are only the bearing preloads to consider. I came into the automotive/truck mechanical trade at a time when Dana/Spicer and others outlined archaic methods for setting up gears and preloads. In updated form, these tools are still provided to dealerships and appear in contemporary factory shop manuals. Note: I have a 6' tall bookcase of FSMs from the 1920s to 2007 that show complex and often expensive tools for axle gear change-outs. Carrier centerline-to-pinion head measuring fixtures date to the 1910s and earliest hypoid gear sets. I have Dana 25 through Dana 80 Miller axle centerline indexing tools that are way more complex than your plate method; these dealership-level tools take longer to use and achieve essentially the same results as your approach...If the axle housing is true with the pinion shaft centerline precisely perpendicular to the carrier bearings' centerline, you can even install gears in a new, raw axle using your method—and Motive's measurements. It has been argued for years that arbor disks, a centering bar and a special pinion block holder for the dial indicator is the only reliable method...not necessarily! Aftermarket tools like bearing cone simulators were the first move away from expensive centerline alignment tools. My bearing bore sanding method is basically a knock-off of the bearing cone tools. If you're not doing these axles day in and out, a set of sanded used bearings will suffice. I have a number of mock used axle bearing sets in my gear work tool box. Label your handiwork for the Dana 30 and Dana 35 axles. Motive has taken the setup method to the next level by focusing on the fundamental goal of gear matching: pinion depth, ring gear alignment and gear backlash. Bearing preload settings are the follow-through steps. Looking forward to your photos... Moses
  7. Another helpful thing I figured out by accident as I was standing in front of my drill press sanding out my test bearings (takes a while) and I could tell my drill press was getting tired of the side loading on its bearings. I considered a spindle sander but those things are pricey even for a cheap one. I am using my table saw top for a clean surface and because it has a ground cast iron surface so it is flatter than my work bench, I stopped sanding to test fit my bearing and the light went off, the other side of the table on my saw is set up for a router. I slid the fence back, put my sanding drum in my router, slowed the spindle speed down a tad, then made quick and more accurate work of it. The bearing can sit on the flat surface and then just work it around the drum sander. Cheap router tables can be found used or even Harbor Freight routers will work. The bearings in a router are designed for side loads so you won't be doing any damage like with a drill or drill press and you end up with a better more accurate test bearing than by trying to hold it flat on the drum with no support under it in a drill press or using a hand drill. Another thing I found on the Motive brand gear set, in addition to the depth from carrier centerline to the top of the pinion gear, they also mark the backlash on the ring gear the set was hone meshed to. On my Dana 30, it was set at 2.261" pinion depth and .006" backlash, that's a very accurate bullseye to aim for and I'm thankful that information was included in the set.
  8. Mudbullet...I really like your suggestion about checking the OE pinion's depth before removing it! Assuming the gear and axle housing are original and accurate, with bearings reasonably fit, you would have a great reference/starting point for shims. Good idea... Your approach with the reference measuring plate is sensible and quickly demystifies the pinion depth set-up if we reuse the same axle housing. Installers need to understand that the pinion depth shim stack varies between pinion gears and also between axle housings or drop-in third members. Using your preliminary depth reading, you can take the pinion head marks from the old pinion and new pinion. If the new pinion offers the Dana +/- marks offered in a mark chart, you can determine the shim thickness difference between the two gears. Adding or subtracting the right shim thickness should place the new pinion head at the right depth. Without +/- marks, matching the pinion depth measurements in the housing will serve the same purpose. Looking forward to your photos...Thanks! Moses
  9. Beserkr...You have been systematic with your troubleshooting and taken a professional tack. Did you test the TPS? Is the TPS an OE item or aftermarket? I have experienced issues with aftermarket O2 sensors and TPS switches, typically with off-shore parts from popular parts stores. The O2 sensor on my '99 XJ Cherokee was older and, as you would reason, I thought it was due for a replacement. I purchased a generic O2 sensor from a well known parts source and immediately experienced mysteriously odd performance. I bought an NTK equivalent to the OE Mopar O2 sensor and promptly resolved the issue. I did the same thing with an aftermarket TPS switch and was amazed just how shitty an engine could run on a cheap TPS switch. For any sensor that matters, I use OE replacement parts or higher quality labels like NTK or Bosch wherever possible. Note: Something as subtle as an aftermarket/Brand-X coolant temp sensor can be problematic. Although the 4.0L Cherokee engine performs okay with an aftermarket CTS, the temperature reads 5-degrees F warmer than it did on the stock sensor—no other changes or causal factors, a surface temp infrared readout reveals that the thermostat housing is actually right at the OE sensor temp of 5-degrees F cooler...I'm just sayin'! Try testing the TPS voltage at various throttle positions and throttle valve angles to see if there are glitches or faults anywhere along the voltage curve. Check the O2 sensor for its part number. Mopar used NTK sensors in our vehicle era, see whether the O2 sensor is NTK, and if so, compare the part number with the OE Mopar part. Let's start here... Moses
  10. I haven't had a chance to do anything this week, I'm starting back on it this weekend. I will take some pics of my tool and how I am using it. Maybe it will help some others to make a faster setup. It could also be used to check the pinion depth before removing an old pinion to get a reference to setting a new gear back up. Thanks for all the help, I'll keep posting with progress.
  11. 97 2.5l tj ax5 4.10 graers 2.5" lift and 31" at tires. Greetings, I'm a first time poster and also a master mechanic. I have owned the Jeep for 6 years, last year the engine lost oil pressure and I got a used rebuilt motor with only 1000 miles out of a 97 tj that got t boned a week after the engine was installed. After about 6 months of driving around the engine developed a miss on cylinder 1 I traced it down to a Crack in the intake runner for that cylinder and changed the the head with a rebuilt O'Reilly head for 300 bucks plus bolts and gaskets. The problem I have had with it all along even with the original engine is a rough idle slow Rev up and slight miss under heavy load and also pops on decel in gear out of the exhaust and also If i do a throttle snap in neutral it pops from the exhaust . I have replaced the muffler and cat, the front 02 sensor, cap, rotor, plugs, wires, coil, distributor, injector pig tails, head, exhaust manifold, lifters, fuel pump module, engine mounts, and radiator. Most of these parts were old and needed to be replaced I wasn't trying to fix the issues with them. I checked the timing chain it is tight and on time, distributor is on time, checked all the sensor readings and all seem within spec, fuel trims are 3% st and 6%lt at idle cruse it's closer to 0% for both and wot it is 0% (I live in Mesa AZ and it's hot as hell and the summer gas sucks here) I think the alcohol content has something to do with the trims being slightly positive. With a vacuum gauge hooked up at idle it is about 19" at 1300 feet above sea level but the needle vibrates about 1 to 2 inches at idle some times especially with the a/c on. at cruse it vibrates about a half an inch of vacuum. Checked exhaust back pressure and it's .5 psi at idle and about 1 to 2 psi at 2500rpm. Also checked the battery and charging system and at 110° ambiance air temp I'm charging at 13.8v and the battery is strong when tested also. This is just driving me nuts any ideas that might help would be awesome! If any more info is needed please let me know?
  12. Sabueso...Sensible to test the CPS when the fault occurs. If you have a surface temp infrared tool handy, you might also test the temperature of the CPS when it faults... Moses
  13. No oil leaks yet. I re-did the motor last summer and haven't driven much due to these problems. But my driveway is oil-free! Having the Jeep since 1990 I've experienced leaking rear main seals a few times. Right now everything in there is super clean. And even with a leaky main seal the Jeep always ran for good long time. In the PDF you sent me before I could see the CPS test. I'll try that test with a warm engine. Thanks again Moses. I'm feeling closer everytime.
  14. Sabueso...The CPS (crankshaft position sensor), like any other electronic device or sensor, can be affected by heat. I'll buy that reasoning. A new CPS based upon the resistance test readings also makes sense. While we're on the subject of the CPS, do you have any oil leaking onto the CPS or the flywheel notches (hall effect)? A leaking rear main seal can raise havoc with any CPS that signals from the flywheel or flexplate. Excess resistance is trouble-making resistance, regardless of the cause... Moses
  15. Another update. I've done a lot of searching on the forums looking for someone with a similar issue. Finally found someone which made sense. I don't have the link, but since this person had the same stall issue after only 30 minutes or so. In fact he stated he could set his watch to the problem. It would act up after 30 minutes of driving. Turned out to be his CPS even though it was a Cherokee, but the CPS was the same as mine. I did more reading and found that a CPS can develop "thermal failure". They can test good and turn on when cold but will leave you stranded down the road from heat or vibration. Can you elaborate more on this Moses? Does it sound logical? I've only replaced mine once and then it was because my cables got cut when I repaired the tranny. But I kept the original. So yesterday I spliced and soldered the cables from my old one to the connector of the replacement. Went for a test but it acted the same after 30 minutes. I think both are bad - my original is pretty old from 1990. The replacement is just Pepboys type that might not be the best and it's over 5 years old. I really think this could be it. The Jeep drives so well for the first 25 minutes. When I installed my original CPS and tested I could actually feel a stronger performance. It was doing 3rd gear going uphill! According to a video, testing ohms at connections B & C should produce NO resistance. On both CPS' I did get some resistance (.209 and .241). Bottom line, I'm gonna buy a new one.
  16. Hi all, I am here to know about the things we can do to secure a mobile app. I have designed a travel guide app. I don't have much experience in mobile app development and this is my first time. I have heard about about virus attacks to app and I want to protect my app and device from malware threats. While searching online for tips to protect the website from threats, I found an interesting one: . I have a plan to integrate more features to this app. Will there be any chances of malware threats when this app goes live to public. Will someone be able to hack the data and build a similar app? What should I do to protect my app? . Is it recommended to approach IT security services and seek their help to secure my mobile app?
  17. Earlier
  18. Mudbullet...This bearing cap seam should index with the centerline of the bearing cone/race. The bearing cap/housing seam should be mid-line of the bearing cup/cone and also the mid-line of the ring gear. I like your approach. Let us know how close this turns out. The Spicer/Dana bare axle housing approach uses discs sized for each bearing cap with a round bar that runs through the disc centers. The only advantage is that the bar is true centerline for both bearing caps. If your plate tool bridges between the two bearing cap machined flats in the housing, this would be nearly the same thing. Motive Gear has a good approach if they furnish the measurement from the bearing cap/housing seam (the bearing cone centerline) to the pinion head. See how that works. Moses
  19. Mr Rex, this has been fun to explore, glad it has been helpful. Like you suggest, I would freshen the transmission with new bearings and a 1st/reverse sliding gear. Gears pop up at eBay all the time, not that rare yet and still somewhat inexpensive. Northwest Transmission Parts (Ohio at was a good parts source when I restored these units in the 2005-2010 period. So the Ford transmissions, based upon your gear tooth numbers and my reference source, narrows down to one of three applications. Their main drive gear measurements would be 8-1/8" or 8-5/8" overall length, measured from the pilot nose end to the synchronizer hub end. The three choices would be: 1) 1960-62 passenger car with the 292 Y-block V-8 or 1958-63 passenger car with the 223 inline six (both use an 8-1/8" main drive gear length and your 18-30T count) 2) 1963 passenger car with the small-block 260 V-8 if the the main drive gear is 8-5/8" overall length You may be able to measure the drive gear overall length by estimating its depth into the 3rd gear brass synchronizer ring. You're only trying to determine whether this is 8-1/8" versus 8-5/8" overall length (O.A.), an obvious half-inch difference between the two. From the top of the case, line up a straight-edge where you estimate the inside end of the input/drive gear should be. Measure to the pilot end of the drive gear. Don't bother taking the transmission apart any further, you should be able get a rough sense for the overall length of the main drive gear without disassembling the transmission. The 1963 260 V-8 would be a rare application like a Fairlane with the 3-speed O.D. This would be the longer input gear application for 260/289 style V-8 bellhousings. A 1958-62 circa Ford passenger car transmission is more likely, but let us know which main drive gear you have here...The O.D. wiring color code is distinctly Ford 12V era; however, it does look spliced. Moses
  20. I certainly appreciate the informative responses that you have offered, before posting here I did not realize how much there is to know about something as mundane as a transmission. Thanks again for your willingness to take the time and respond in such detail. Here are more specifications from this transmission based on the questions you asked earlier: 1. input /main to cluster gear ratio: 18:30. (Counting the cluster gear teeth was a little difficult since it is hidden below the input gear, but after several iterations of turning the input shaft and squinting at the gear teeth, I settled on 30.) 2. input shaft spline count: 23 (your hunch was correct.) 3. length of input shaft; 153 mm, or 6 inches. (I am unsure of the measuring points for this specification, so I attached a photograph) 4. Its definitely a Ford application, the little tag on the top of the transmission with the "303-D-1" also has a Ford symbol etched into it. 5. The casting number found on the left side of the case between the two shift lever shafts: A15-3 (see attached photograph) 6. for the sake of full disclosure, the 1st/reverse slider gear looks like it will need replacing. one side of the gear clearly shows that it had been slammed into gear before the vehicle was fully stopped. (see attached photograph) Please let me know if you have additional questions, and I thank you again for your interest in this.
  21. I think the pinion depth is going to be a fairly easy job, Motive has the distance etched on the pinion of the inner pinion face to centerline of carrier, 2.038" I believe (don't have it in front of me) as the distance the ring and pinion were match honed to run together. I have a piece of plate that I had parallel ground on both sides and hole through it to use a depth mic. By placing the plate on the bearing cap surface in the housing and checking the distance to the top face of the pinion, then subtracting the plate thickness should get me near dead on the correct shims if I have the pinion in with no shims and snugged down to about 80-100 ft/lbs. It seems it would be at least as accurate as the Ratech tool I see advertised. Do you see any issues with this home brew pinion gage I may be missing? I am assuming the bearing cap surface is parallel to the pinion race seat and perpendicular to the pinion axis. Once I have that set, then setting the carrier for backlash and preload shouldn't be too bad, trial and fit until it's laying a good pattern and the backlash is where it needs to be. It comes back to the shims for the pinon preload that gets me thinking too much. The old bearing races I will be using are dulled but no wear I can detect with a "thumbnail mic", there's no pitting or spalling and they spun quietly on the bench.
  22. Nate...On your behalf and that of many other Jeep 2.5L TBI troubleshooters, I put together a comprehensive list of PDFs covering the troubleshooting of 2.5L TBI, diagnostics and adjustments like you're attempting. Here is the forum page: You will find information in the first PDF on the list that thoroughly covers the ISA motor and closed throttle switch, including wiring diagrams and diagnostics points. The ECU pinout shows the pins for extending and retracting the ISA motor. There is also a clear illustration of the ISA motor/closed switch connector. If you follow the wiring diagram that I also included for your "Model 81" Jeep YJ Wrangler, you can find the pin sockets at the ISA motor connector for the ground, the hot and the retracted or extended positions of the plunger. Read the PDF that covers adjustment of the ISA/closed switch and references to how far the plunger should extend and stop. You can test the ISA/closed switch this way. The PDFs are actual factory testing and adjustment procedures. You can simulate the "ele. AB.99" tool's functions by disconnecting and powering up the ISA connector directly. Determine the ground, hot, retract and extend pins. If you make a battery jumper, be sure to fuse the jumper to protect the ISA motor and wiring. Avoid playing with the ECU connector other than to trace wire color codes back to the ISA connector. Moses
  23. Here is 1987-90 Jeep YJ Wrangler and Jeep XJ Cherokee/MJ Comanche 2.5L TBI diagnostics information in PDF form. The first document includes all sensor and switch tests plus adjustments that affect engine tune, idle and reliability. Wiring schematics and ECU pin locations, test plugs and diagnostics included. Jeep 2.5L TBI Complete Diagnostics-Sensors-Switches.pdf Jeep 2.5L TBI ECU Inputs and Outputs.pdf Jeep 2.5L TBI MAP Sensor Test.pdf Jeep 2.5L Timing Chain and Tensioner.pdf Jeep 2.5L Valve Timing Check.pdf Jeep YJ 2.5L TBI Sensors and Pinout.pdf YJ Wrangler 2.5L TBI Wiring of WOT to ECU.pdf Jeep YJ 2.5L ISA Wiring Diagram.pdf 1987-90 2.5L TBI Intake Manifold and Sensors.pdf 1987-90 YJ Wrangler 2.5L TBI Emissions System Parts.pdf YJ Wrangler Fuel Filter and Guard.pdf 2.5L TBI ISA Motor Adjustment.pdf Used in conjunction with the many forum exchanges (search under "All Content" and "2.5L TBI" in the search box), plus the Jeep 2.5L TBI troubleshooting article at the magazine website, this information will help solve your Jeep YJ Wrangler or XJ Cherokee 2.5L TBI troubles. In references, the Model 81 is the Jeep YJ Wrangler. The Model 60/70 is the XJ Cherokee and MJ Comanche Pickup. Moses
  24. Here is 1987-90 Jeep YJ Wrangler and Jeep XJ Cherokee/MJ Comanche 2.5L TBI diagnostics information in PDF form. The first document includes all sensor and switch tests plus adjustments that affect engine tune, idle and reliability. Wiring schematics and ECU pin locations, test plugs and diagnostics included. Jeep 2.5L TBI Complete Diagnostics-Sensors-Switches.pdf Jeep 2.5L TBI ECU Inputs and Outputs.pdf Jeep 2.5L TBI MAP Sensor Test.pdf Jeep 2.5L Timing Chain and Tensioner.pdf Jeep 2.5L Valve Timing Check.pdf Jeep YJ 2.5L TBI Sensors and Pinout.pdf YJ Wrangler 2.5L TBI Wiring of WOT to ECU.pdf Jeep YJ 2.5L ISA Wiring Diagram.pdf 1987-90 2.5L TBI Intake Manifold and Sensors.pdf 1987-90 YJ Wrangler 2.5L TBI Emissions System Parts.pdf YJ Wrangler Fuel Filter and Guard.pdf 2.5L TBI ISA Motor Adjustment.pdf Used in conjunction with the many forum exchanges (search under "All Content" and "2.5L TBI" in the search box), plus the Jeep 2.5L TBI troubleshooting article at the magazine website, this information will help solve your Jeep YJ Wrangler or XJ Cherokee 2.5L TBI troubles. In references, the Model 81 is the Jeep YJ Wrangler. The Model 60/70 is the XJ Cherokee and MJ Comanche Pickup. Moses
  25. Mudbullet...I do have a suggestion that might save time...After making your trial bearings for the pinion and carrier, install the pinion without any shims, and tighten the pinion flange nut snugly. Set the carrier in position without shims and use the bearing caps to hold the bearing cups/races where you want them. Jockey the ring and pinion gears to simulate the rough gear alignment and backlash; establish a reasonable tooth contact pattern then tighten the bearing caps enough to hold the carrier cups steady—without perceptible carrier lateral movement. Use a dial indicator to see how much pinion shaft end play there is between the point that the gears come together with a reasonable tooth contact pattern and the outer position of the pinion shaft when you pull the shaft straight rearward from the axle housing. This end play measurement will give you a rough shim pack starting point. Install the rough stack shims and check the pinion shaft end play again while keeping watch on the tooth contact pattern. Now you can fine tune the shim packs to get the right contact pattern. Finally, add or subtract the necessary shim thickness for proper bearing preloads, correct pinion depth and backlash. Note: All this time, the tooth contact pattern should be governed by Dana/Spicer chart views of proper tooth patterns for the Dana 30. You'll do the same with the Dana 35 rear axle. Keep in mind that final torque on the pinion nuts will flatten shims and alter the settings. Allow for this by tightening the old/test pinion nut securely during your final trial tests...This will help make your new bearing and pinion nut settings match up with the test settings. We've discussed trial bearings. These bearings are running in the original races if those races are okay. You shared that they've only been installed a short time, presumably the races are not damaged. Once you get your trial fit (pinion depth, carrier centering for the right backlash, and the preload shimming for the bearings of the Dana 30, you can disassemble and change out the races. Again, there should be only a slight variance between the old cup and cone settings and the new bearing cone and cup/race settings. Try to estimate that slight difference so that your final assembly will put the bearing preloads, gear backlash and pinion depth exactly where you want it. Moses
  26. Thanks, that's kind of what I expected to hear but was hoping there was a "range" on the pre-load stack. At least they did install new Timkens on the pinion when they installed it and I am using new Timkens back so the pinion depth should be pretty easy to get right. The carrier pre-load seems good when I pulled it having to use a small prybar and some enthusiasm.I found a mess in the spider pin where they had use a 1" long roll pin, knocked through so it was only holding on the flange side of the carrier, then they drove another used pin on the button side, bent it over and cut it off, then staked around the hole. I am sure at this point the pinion nut wasn't the only nut involved in this job. I don't have and can't locally source the right roll pin to hold the carrier pin, I'm setting this whole mess aside and just ordered new Tru-Tracs for front and back. If I'm going to have to do a long process trial and set-up, I may as well do it on something strong and useful. Thanks for the help. As the old saying goes, it's hard to find good help these days.
  27. Nate...You're rightfully frustrated if the Jeep has not been roadworthy...I'm guessing you read through the ISA adjustment procedures in the extensive 2.5L TBI coverage here at the forums. Here is a quick recap in the PDFs: Here is the factory ISA motor adjustment procedure. Use great care when running the engine speed up. Stay away from the engine's cooling fan! (One way to eliminate risk of fan injury during this adjustment would be to temporarily remove the drive belt.): 2.5L TBI ISA Motor Adjustment.pdf Read these additional details on Closed Throttle (Idle) Switch testing in conjunction with the ISA motor and adjustments before performing ISA motor adjustment and tests: Closed Throttle Idle Switch & ISA Testing.pdf Note that I suggested a Closed Throttle (Idle) Switch test alongside the ISA Motor adjustment. There is a need to recycle the ISA if you adjust it incorrectly. When you read the ISA steps, the plunger needs to be actuated with the actuator tool before you set to 3500 rpm. Again, stay away from the fan or disconnect the fan belt to eliminate risk of injury with the engine running at this relatively high speed. Don't lean over the fan! If you are not actuating the plunger with the ISA connector uncoupled, you will not be able to get an accurate setting of 3500 rpm. I doubt you have access to the "ele. AB.99" tool. Here is the link to my 2.5L TBI troubleshooting article at the magazine, which helps explain the relationship between the various devices and symptoms associated with problems: There is a close relationship with the Closed Throttle Idle Switch, the ISA Motor and the TPS. Read through my article, it's well illustrated. See if any one of these three devices could be causing your idle speed trouble. We can resume the troubleshooting process once you have reviewed the information... Moses
  28. Mudbullet...Glad the article works well. You're in a dilemma here and need to go with your test/used (reasonably good condition) bearing approach. Spend time relieving the old bearings' inside bore sizes enough to allow the bearings to slide onto the pinion shaft and carrier flanges with even finger pressure. Keep these inner bores concentric, no looseness or bind, when grinding or sanding the bore. I've found that inexpensive 1/4" shank drum sanding discs from Lowe's or Home Depot will work as well as arbor grinding stones. Course works best on bearing steel, finer may be useful for polishing/finishing. Expect sanding paper to go away quickly when using a 1/4" drill motor on bearing steel. Here's a typical kit from Home Depot, you can get an even cheaper type, whatever you care to spend: I suggest that you first trial fit without approaching full torque on the pinion nut. For trial rough fitting, you're just trying to seat the bearings and fully flatten shims; full torque application is not necessary until you're reasonably close to the right shim stack. This will work for the YJ Wrangler front Dana 30 since you're relying on shims for both pinion depth and bearing preload (not a crush sleeve for the preload like the Dana 35 rear axle). Overall, you have one of two choices: 1) invest in an expensive bearing cap arbor pinion depth kit from Miller/OTC to establish the baseline pinion depth or 2) get yourself plenty of tooth contact marking paste and shims. If you choose the likely option #2, you'll need to assemble the differential and ring gear/carrier with new ring gear bolts and Loctite 271 on the threads; then after installing the pinion shaft and bearings with trial shims, you can roughly fit the carrier into the axle for trial testing. This can be done with trial bearings and just enough shimming to take out all lateral play at the carrier bearings; at the same time adjust the gear tooth backlash within factory specification. Run a tooth contact pattern test with a slight load on the pinion flange. I use a shop rag as a "tourniquet" around the flange neck to get a good tooth impression in the marking compound. Rotate the ring gear with a box-end wrench applied to previously torqued bolts. If you trial fit with good used bearings (their bores sanded out to a finger-press fit), you'll be very close to the final fit and preloads. If anything, there will be only minor shim adjustment at the end. Keep in mind that the high final pinion nut torque will thoroughly crush the shim stack, and this could change both the pinion depth and the bearing preload. Note: As an additional point, I do not trial fit with a new pinion nut. I save the new pinion nut for what I'm sure will be the last fit-up and torque setting. You can even grind the outer pinch thread off the old nut for trial fitting. This will allow quick tightening and removal during the testing. For final tightening, install the new pinion nut with Loctite on the threads for insurance and additional sealing. The Dana 35 rear can also be trial fitted. Use the old crush sleeve for trial testing; you're initially just trying to seat the good used trial fit bearings and flatten the shims enough for an accurate pinion depth reading and approximate bearing preload setting. Final pinion nut torque is critical at both the Dana 30 and Dana 35 axles; you will need a new crush sleeve at the rear pinion for final preload setting once you're confident you have the correct pinion depth and have installed the new bearings. Be very careful not to over-tighten the bearing preload on the 35, or you will be installing another new crush sleeve. If crushed too much, the sleeve must be replace. You cannot back off the nut and leave a lighter torque setting against the sleeve. The nut may come loose in service. Final pinion nut installation requires a new pinion nut with Loctite on the threads. The tooth contact pattern method is not what you want to hear, but it can ultimately get you the results you want. Given that you're essentially starting from scratch (there's no magic starting shim stack), the contact pattern will be your only assurance that you've got the pinion depth right. Pinion bearing preload is the easier part, though many prefer the crush sleeve to a shim stack preload setting. Trial bearings will make all of this a lot easier. If your trial bearings have minimal wear, the new bearings will be a very close match. You'll be able to press new bearings in place without having to remove them off for additional shim work. In my experience, quality bearings with close tolerance standards almost always match or interchange. A good original bearing should be a very close fit to the new bearing, especially for shimming purposes. Use your intuition here; compensate slightly for any bearing wear. Moses
  29. I hate to bring this up again, but I need help. I have a 1990 2.5 TBI wrangler that is killing me! I say I've been throwing parts at it, but given it's age everything I've done was either bad or well on its way. Now that almost everything has been replaced including the IAC I need help adjusting it. I assumed the IAC was in the correct position when I replaced it, but I'm suspect the PO had adjusted it when some of these parts I replaced went bad or possibly when they plated off the EGR (I replaced the egr and cleaned the egr tube) and now I find myself trying to adjust the IAC. I've adjusted it twice. The first time I was very close, but was not perfect so I adjusted it a turn more and it's acting up again. I've ready your very helpful advice, but call me slow I could use a bit more help or even pictures on how to do it the way you describe. The adjustments I made were before I found this page and I was told to just unplug it adjust it to 3500 rpm turn it off, plug it in, start it up for a minute then reset the ECU and I'd be good to go. Which is "close" to what I read here but miles away too. It did make it much better, but one more turn and it's back stalling out again. Can anyone give me pictures or better yet a video? I've hardly been able to drive the jeep since I purchased it.
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