Comanchewithacamper Posted March 3, 2021 Share Posted March 3, 2021 Hello to everyone who also owns the single best and coolest vehicle available. I have an 88 comanche and I'm having an odd issue that I can't seem to figure out. A couple days ago I replaced a leaking thermostat housing gasket. I took it on a test drive to get some of the air out of the system and noticed it was bucking a little. I took it to Auto Zone to get the battery and alternator tested and they tested great. I figured I should just go ahead and baby it home, which was about 2 miles. I was cruising down the road when it just died for a second and came back to life and backfired like a 12 guage shotgun blast. This is the first time since I've owned it that it's backfired. Just as I made the decision to pull into the next parking lot, it did it again, this time it exploded the muffler. At this point it barely had enough power for me to slip the clutch enough to keep it rolling in 1st gear. I did end up having to move it a little further into the lot and this time it started to die like it did earlier except a plume of white smoke came out of the breather box. Now when I start it, it will idle fine for a few seconds, then it will surge between almost dying to normal idle. It doesn't surge up and down either, it idles for a few seconds and almost dies once then repeats until it dies for real after a minute or so. It sounds like it's having trouble staying running like it's too rich or something. So far I have: -Replaced a very sooty oxygen sensor - no catalytic converter -Cleaned and checked plugs -Cleaned and checked injectors -Tested the coolant temp sensor towards the bottom of the block -Tested the intake manifold temp sensor -Tested the MAP sensor - after the backfires, the line to the MAP sensor was broken so I replaced the line - Changed fuel filter - Compression check - 150psi on all 6 - Fuel pressure check - 30-32psi while running - checked bumper vacuum ball - visually inspected anything I could see while fixing a couple little vacuum leaks along the way A little history right quick. I've had this truck for 8 years. I pretty recently installed a remanufactured 4.0 in this it and replace all the coolant system and most all the vacuum lines and sensors while we were at it. For the most part, everything under the hood has about 20,000 miles on it. This is usually my reliable vehicle so I'm not sure what's gotten into it. Also, it has driven perfect multiple times a week until that day, which was about 4 days ago. Other than changing that one gasket, no changes had been made between it running like a top and the day I have described. Has anyone experienced this or a similar issue that can point me in the right direction? Link to comment Share on other sites More sharing options...
jdog Posted March 3, 2021 Share Posted March 3, 2021 it sounds like a plugged exhaust or the timing has jumped either the timing chain has skipped a tooth or there is a issue with the dist. I would inspect the distributor first, and inspect the rotor inside. Link to comment Share on other sites More sharing options...
Comanchewithacamper Posted March 3, 2021 Author Share Posted March 3, 2021 @jdog I'm gonna check out that distributor tomorrow. I've had a few issues with it in the past so I guess I wouldn't be too surprised if it's bad. If not I'll hit it with a timing light. Thank you Link to comment Share on other sites More sharing options...
jdog Posted March 3, 2021 Share Posted March 3, 2021 No problem, my cherokee starting doing weird things like that when it's dizzy broke. Link to comment Share on other sites More sharing options...
89 MJ Posted March 3, 2021 Share Posted March 3, 2021 I'd second the timing being off. I think it is purely coincidence that it happened after changing that gasket. You may also want to check to make sure you consistently have spark. If you don't, that could lead to a number of potential issues, from just broken wires to the CPS to a bad coil, etc. Link to comment Share on other sites More sharing options...
Comanchewithacamper Posted March 4, 2021 Author Share Posted March 4, 2021 I pulled the distributor cap this morning and didn't see any obvious problems. There was some rotational and a little up and down play but it doesn't seem excessive. Maybe an 8th inch in either direction and about the same up and down. There was a little side to side play in the shaft as well, just enough to feel it moving around. Is the stator/pick-up coil/cam position sensor something I can test by unplugging it? Link to comment Share on other sites More sharing options...
cruiser54 Posted March 4, 2021 Share Posted March 4, 2021 The stator can be unplugged and it will still run. Link to comment Share on other sites More sharing options...
Ωhm Posted March 4, 2021 Share Posted March 4, 2021 On 3/2/2021 at 9:19 PM, Comanchewithacamper said: It sounds like it's having trouble staying running like it's too rich or something. Check vacuum hose between Fuel Pressure Regulator (FPR) and intake manifold for raw fuel. Leaky FPR. Link to comment Share on other sites More sharing options...
MiNi Beast Posted March 4, 2021 Share Posted March 4, 2021 18 hours ago, Comanchewithacamper said: I pulled the distributor cap this morning and didn't see any obvious problems. There was some rotational and a little up and down play but it doesn't seem excessive. Maybe an 8th inch in either direction and about the same up and down. There was a little side to side play in the shaft as well, just enough to feel it moving around. Is the stator/pick-up coil/cam position sensor something I can test by unplugging it? do the timing light check. as i bet distributor is bad possibly the block has issues as well. depending on the reman 20k seems about right for issues. Link to comment Share on other sites More sharing options...
grouch Posted March 5, 2021 Share Posted March 5, 2021 As a kid we used to drive down the street, turn off the ignition, floor the gas and then turn the ignition back on....big BAM and flames out the exhaust. It would scare the hell out of everyone . With that stunt in mind, think interment ignition like a lose wire or failing module. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 6, 2021 Share Posted March 6, 2021 Remember those days well.... Link to comment Share on other sites More sharing options...
MiNi Beast Posted March 6, 2021 Share Posted March 6, 2021 21 hours ago, grouch said: As a kid we used to drive down the street, turn off the ignition, floor the gas and then turn the ignition back on....big BAM and flames out the exhaust. It would scare the hell out of everyone . With that stunt in mind, think interment ignition like a lose wire or failing module. better then a whistler. Link to comment Share on other sites More sharing options...
Comanchewithacamper Posted March 8, 2021 Author Share Posted March 8, 2021 I unplugged the stator and it ran the same, except it started acting up the same way a little sooner. Is the stator suspect? Every vacuum line I can see is in good shape and holding vacuum. I replaced a couple and made some adjustments to repair the valve cover breather. (This didn't post from a couple days ago so I'm going to add on) Today I made sure the engine was at top dead center and replaced the whole distributor with a known working one. I started it and it ran pretty rough and kept dying. I was advised to cut the tabs (like was done on my previous one) to get some adjustment out of it. I still couldn't get it to run and eventually when it did it ran until it had the same problem. Link to comment Share on other sites More sharing options...
jdog Posted March 8, 2021 Share Posted March 8, 2021 15 minutes ago, Comanchewithacamper said: replaced the whole distributor with a known working one Did you perform a dist index? If not it's http://cruiser54.com/?p=68 Link to comment Share on other sites More sharing options...
Comanchewithacamper Posted March 9, 2021 Author Share Posted March 9, 2021 Other than cutting the hole in the cap I did. Instead i had marked the #1 point on the distributor body. When I did get it running, it ran and died like it had before. I have been doing a little reading and I'm wondering if I should replace the crank position sensor. Link to comment Share on other sites More sharing options...
Comanchewithacamper Posted March 13, 2021 Author Share Posted March 13, 2021 Replaced the crank sensor, cleaned the throttle body, and replaced the idle air control valve. No change. I really thought I was on to something with the IAC valve. I pulled it out and wiped it down gently and put it back in. After that alone I was able to drive it for the first time since the issue started. It ended up having some trouble on the test drive, but it drove home. Now that I have a new one installed it's back to the same issue. Link to comment Share on other sites More sharing options...
Comanchewithacamper Posted March 19, 2021 Author Share Posted March 19, 2021 The Fix turned out to be the ignition control module. It's got one off another comanche but now I'm going to try and source a new one Link to comment Share on other sites More sharing options...
MiNi Beast Posted March 19, 2021 Share Posted March 19, 2021 right on glad its figured out. Link to comment Share on other sites More sharing options...
grouch Posted March 20, 2021 Share Posted March 20, 2021 Guess I wasn't too far off...........Glad you got it going. Link to comment Share on other sites More sharing options...
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