imtehbeef

Nope, the TPS on the 91 and 92 Comanche's are nonadjustable.

KgOD78gnV6M If you listen closely you can hear it misfire 2 or 3 times in this video. I kept it floored until after it shifted.

Sometimes the misfire happens a good 1000 rpms away from the shift point. As for the ECU noise, I couldn't get it on video because my phone microphone won't pick up such a high frequency, but its just a faint high pitch whine that you can only hear when you're under the hood. I've heard the whine come from an ECU in one of my previous trucks that ran fine, but I can't remember if it was a Jeep or not. In other news, I decided to check the new TPS voltage just for kicks, and its only putting out 3.6 volts at WOT. My Chilton says it should be putting out over 3.9 volts. Did I get a faulty TPS unit? This would cause the engine to lean out at WOT and cause a misfire, right?

Thats the thing I don't understand. It doesn't knock or misfire at all until it gets close to shifting, and usually only at WOT. I can power brake all day long and it won't misfire once. I'll try to take a video of a 0-60 pass at WOT in a little bit. It's still not throwing a misfire code, either.

I couldn't pull the plate off of the transmission to clean the ring gear, because I don't have a wrench big enough, but I was able to take one of the small bolts off and pry the plate open. What exactly am I looking for to be covered in oil? The ring gear looked pretty dry. I also noticed that the high pitched whine that the ECU makes changes when I unplug the crank position sensor and the cam position sensor. I'll try to post a video when I get back from town.

Yeah, I do have a rear main seal leak. I remember reading somewhere that this could cause problems with the CPS, because the pickups get oily? Should I go clean the pickups and see if it helps?

I don't think its the rev limiter. It keeps accelerating in between misfires. It does seem to be doing it less today, although I haven't had a good stretch of road to test it on. It's hard to test a misfire at the top of first gear in a 25 mph zone. :wall:

I won't have access to a timing light for another week and a half, when school gets out. I think it runs way too good for it to be a timing problem though. The truck accelerates like a madman at WOT until it gets close to redline, and then it starts to misfire. I'm not sure the exact RPM, I have the idiot light gauges :shake:. Occasionally the truck will go all the way to redline without misfiring, but its completely random when it does it. When I test drove it after adjusting the kickdown cable, it misfired 4 or 5 times on the first pass, once on the second pass, and then 4 to 5 times on the third pass.

Cable is adjusted, and its still doing it. Could the torque converter be the cause? The truck was run low on transmission fluid by the previous owner. It stumbles in every gear too. Any ECU from 91-95 should fit, right? My ECU does make a weird high-pitched whine when the key is on. Off topic, do you happen to know where I can get an FSM for a 92? I've been using the 93 FSM for a Cherokee I got from greatlakesxj.com

That sounds like a likely culprit. I've been trying to get this mother@#$%er to throw a code for 3 weeks now, and no matter how bad it "misfires" it won't throw a code. Did your 91 sound like a misfire when it stumbled? And how would I go about adjusting the kickdown cable? I followed some instructions I found online (can't remember where exactly) but it didn't seem to adjust the cable, only pull it really tight.

Well, I checked the IAT sensor today with the truck fully cooled down, and its within factory specs. I ripped the catalytic converter off, thinking it might be a partially clogged cat, but that didn't fix it either. I'm runnin out of stuff to check here people. Anybody got any ideas at all?

Is the depth of the pump going to make a difference? For example, am I only going to be able to use 18 gallons out of my 23.5 gallon tank before it stops sucking fuel? I've been searching on CC all night but it doesn't seem like many people are running Cherokee pumps.

I just got off the phone with the PO of my Comanche, and he gave me the part number for the pump he put in. RE0289S. This comes up on RockAuto as a Cherokee fuel pump. I assume this is why my fuel gauge will only go down to a little over 1/4 tank. Is this gonna cause any problems other than the fuel gauge reading wrong? It seems like every day I take 1 step closer to finishing this truck and then find 10 more steps I didn't know I had. :wall:

Checked the fuel pressure, 39 without the regulator, 31 with it. Bought a brand new coil. Still misfiring. I checked the resistance on the injectors, all are approximately 15 ohms. I'm out of ideas. Everything on the fuel/ignition system is new. Would a bad intake air temperature sensor cause this? The resistance at 60 degrees is only 5k ohms, the book says it should be above 10k.

Its late and I'm tired, but if my brain is still working right, there is a 2-2.5" height difference between the front and rear when measured from the center of the hub to the bottom of the fender flare.