Disturbed

I ran through the first 5 steps and actually discovered 3 things. 1. The C101 connector had already been cleaned out, no black tar and it looks to be in good shape, someone had even added some sort of gel, like you see in the gel filled connector, to prevent corrosion. 2. The ground strap at the rear of the head was MISSING, nothing there, but there was one on the intake manifold so I picked up another ground strap at NAPA and added it to the rear of the head. 3. I definitely had an issue in the grounding in the wiring harnass, probing the TPS and checking to battery negative I would see the continuity come and go when shaking the wiring harnass. Pulled the wiring harnass apart and did the sensor ground upgrade, everything seems good now, time will tell but it has been fine since Saturday. Thank you very much for your help.

Yes it is an 88, sorry I didn't mention that. I found your post and bookmarked it, I will try that tonight. SUPER important to do all 5 of them. Won't take but an hour and half maybe. I printed your tips out and as soon as the weather cooperates I will be going through at least the first 5, all of them if I have the time. Thank you very much for your help.

Yes it is an 88, sorry I didn't mention that. I found your post and bookmarked it, I will try that tonight.

I think these two issues may be related but am not sure. My MJ decides at random not to start, always when it is a cold start and have never had it die while driving. Sometimes I can let it sit for a few minutes and it will fire right up, sometimes it takes longer until it will start, this weekend it just refused to start. I was getting no spark. Pulled the coil and ignition module, coil tested OK after I cleaned up the terminals but decided to replace it anyway since the terminals were corroded on both the coil and the ignition module. Threw the new coil in, nothing. Had AutoZone order me a new ignition control module for Sunday. Sunday I installed the new ignition module and it started right up, no issue and was running very smooth. For kicks I put the old ignition module back in, and it fired right up. I was still hopeful that it was a flakey module, had one on a YJ I had and a new module solved the problem. Put the new coil and module back in and called it a day. Monday morning started right up to go to work, and to go to lunch, and to go home, started a few times last night shuffling cars in and out of my garage doing maintenance on them and running to AutoZone to get an oil filter for my wife's car. No issues with the truck all night. This morning me and my boy hop in the truck to get him to daycare and it will not start. Same thing as before, cranks fines but no fire. Let it sit a minute or two, nothing. Couldn't wait any longer so we hopped in the ZJ and I took him to daycare. Ran back to the house after dropping him off to try it one more time before work, still nothing, just like it was doing on Saturday. I am not sure if it is a related problem but when I crank the engine over longer than normal, sometimes when I release the key the engine just keeps right on cranking. I believe that problem may be in the starter relay that is on the fender, I was going to replace that as well but AutoZone did not have a listing for that and I have not had an opportunity to look elsewhere. I am not sure if these issues are related and they very well may not be, the truck is 25+ years old after all, multiple unrelated issues at the same time would surprise me. If anyone has any ideas I would greatly appreciated.

Well I tried to post a reply with pictures as to how I am accomplishing this but I was getting this error, "You are not allowed to use that image extension on this community." I have no idea what that means put here is a link to my local Jeep club board where I am also posting what I am doing. If you want to check out the pictures, not all of it is very interesting but I built a pretty trick skid/protection plate for the fuel filter since it will be mounted on the front of the gas tank skid plate. http://www.jeepsrus.org/MegaBBS/forums/thread-view.asp?tid=3490&posts=7#M20347 I'll post an update once it is in a running.

Thank you gentlemen. I had a response typed up to the "that's stupid" response but as far as I am concerned I am a newbie on this site and did not feel it was in my place to start something or challenge someone who is obviously a long time member. I have a real problem keeping my hands on things, if the fuel tank wouldn't be so new I would be putting a fuel cell in it too. I actually was checking out the JAZ fuel cell sitting in my shop for my buggy rebuild but it wasn't quite right as far as I was concerned and I would like to keep the stock filler location. This is not a wheeling rig, it is my DD. I have had a lot of luck with using external fuel pumps. Not sure about the jet turbine idea but my cousin-in-law seems to fall into 5.9 ZJs all the time, I think he has 3-4 or them right now so there is always the 5.9 option....hmmm. I will post up some pictures when I get it installed. Just got notice that the pump has shipped from Summit, I should have it tomorrow.

Unfortunately every one I have seen will not even mount in my mount without hacking up the the top cap portion of the mount that holds the pump in place. If I am making changes I would prefer to do the external pump set up. I have run a number of vehicles with external inline pumps and they don't bother me. Sure they are louder but this is a 24 year old truck, its not like I can hear it over everything else. Besides the one that just failed was not super quiet. I am all about being able to swap a fuel pump with a screw driver and a couple of nut drivers.

The Summit pump is already on the way, the E2000 pump costs slight more than the universal pump I purchased. The return line and the regulator on the fuel rail are still in place so there should not be an issues there. I guess we will find out when I get the pump gets here is everything works like I think it will.

Well the fuel pump on my MJ finally went out. It had been getting louder and louder and I knew it was on its last leg and was just a matter of time. It left me sit about 2 weeks ago. Finally last weekend I got to look at it.. Pump has power and everything is functioning as it should expect for the pump. Dropped the tank and pulled the pump and tested on it the bench. 12v directly to the pump and nothing, it is locked up. Spend a bunch of time trying to find a fuel pump to replace the in tank unit and it seems I have an odd pump. I checked a number of places online, had Napa order in a few different pumps that were not the same as mine, checked with the dealership to find the pump is discontinued from Chrysler. Everything I have seen is close but none of them will fit the mount . If you are familiar with the stock pumps and the way they look everything I have found has four "lobes" on the top. My pump only has three "lobes and the mount is made specifically for a that shape on the top of the pump. I reached a frustration point and ordered up an external pump from Summit Racing. This is the pump I have on the way, http://www.summitracing.com/parts/sum-g3138 45PSI/43gph which should work well with the MJ. I have a number of vehicles I have run on external fuel pumps and have never had any issues with them. I am going to extending the pickup down to the bottom of the tank using metal fuel line and retain the OEM strainer. Also plan on retaining the fuel level float. Pump will get mounted on the frame rail near the fuel filter. It should not be too diffiult. I am hoping the pump shows up tomorrow so I can work on it over the weekend. The only down side to this project is I must do it outside. I have a big garage with a lift in it but unfortunately it is full of projects including my Rock Buggy on the lift that is missing most of the tubing and the rear air shocks so there is no way to move it. If anyone has tried this before using a stock tank I would like to here about your experience with it. I have done it on a Jeep YJ with a stock fuel tank for a TBI conversion but never on a multiport injection system. I will try to get some pictures once I have this done.

OK I was able to fix this problem, it was in the TPS. I am thinking in the plug. I pull the connector off of the TPS to test the wiring, everything tested fine. Plugged to TPS connector back in an back probed the TPS, all of the readings were good there also. Fired the MJ up to see if it made any difference with it running, no everything tested fine but I also noticed that when I revved it up it was no falling on its face. Took it out for a drive, problem was gone. Drove it about 30 miles between yesterday and this morning to work and the problem seems to be completely gone. I am thinking that one of the pins in the TPS connector was not making a good connection anymore, from unplugged and plugging it back in and messing around with the pins while doing the testing that connection issue has been corrected and now the ECU is getting the reading it needs. Either that or is was just a coincidence that the problem went away after messing with the TPS. In either case my MJ is back on the road.

OK worked on it more today. Replaced the IAC, not that I thought that was a problem, but I knew it was problematic so i replaced it. That fixed the idle problem but not the stubbling issue. Also replaced the MAP sensor, call it a shot in the dark, no difference. Tried bypassing the fuel pump ballast resistor and that made not difference. Tested the EGR solenoid and it functions properly. Hooked a vacuum pump to the egr valve and you can see that cycle so it seems as if that is working although bypassing that permanently might be a good idea. It acts the same way whether the truck is warm or cold, when I did my test drives today I started it up and ran 1/4 mile down the road and back, same issue so it was not warm enough to pull the EGR valve in. Still seems like a fuel issue but I hate to replace the fuel pump just to check it, especially since the fuel pressure tests OK and I can get it to do this in the driveway and see that the fuel pressure is not dropping. Any other ideas what may be causing this? Anybody think the TPS could be causing this? Since it does it warm and cold I do not think it could be the CTS, besides at WOT the computer should be running in open loop mode and ignoring the CTS. It does this in both open loop and close loop mode. If the engine runs fine an idle I think that rules out the CPS and the sensor in the distributor, if there was an issue there I would have an issue at idle and when cursing but the truck runs fine at an idle and when curing under light load. Load should have no affect on these sensors if there was an issue with them, am I wrong about that? Considering replacing the fuel filter. and just because it is cheap and easy. I am really going to kick myself if it does turn out to be the fuel pump. Anyone have a good plce to buy a fuel pump at a good price, the pump in my truck is a Bosch pump. Any idea's someone may have would be greatly appreciated, I really want my truck back on the road, I miss driving it.

No cat and the exhaust is all new from the manifold back in the last year.

I agree but I can get it to die just revving it up sitting in the driveway, even when it dies the fuel pressure is still reading between 30-39psi depending how hard I hit the throttle. I would think if the fuel filter was plugged up I would see a drop in the fuel pressure when it dies off and I don't, it seems to have plenty of fuel, if the pump wasn't keeping up, whether it is the fuel pump or a plugged filter I would see the fuel pressure drop off when I rev it up but I don't see that. Fuel pressure never drops below 30PSI and increases when the engine is revved up, That is what has be so confused. Thinking maybe I will try bypassing the fuel pump resistor to see if that makes a difference.

OK finally got around to messing with the MJ. Put a fuel pressure gauge on the rail. 30PSI at an idle, 39PSI with the vacuum unhook from the pressure regulator, Jumps from 30psi to 39psi when I try to rev it up but it still falls flat on it face, so it does not seem like a fuel issue. The truck had sat for a few days without being driven before this started to I pulled the air filter to see if some critter has built a nest in the air box, nothing the air box and filter are clean. Like I said the IAC was giving me issues so I am going to replace that but do not think that would cause this issue. If the fuel filter was clogged I would think I would see that in the fuel pressure. Anyone have any other ideas. It getting expensive driving my V8 ZJ and I want me truck back up and running..

That will be my first step when I have a chance but I didn't know if the resistor for the fuel pump would cause something like that, I am not very familiar with that setup and and do not know if a faulty resistor could cause issues like that.

Something new has developed with my MJ. Truck is a 1988 MJ with a 4.0 and Renix injection, 5 speed transmission. If I accelerate like I am driving Miss Daisey I am fine but if I tried to accelerate any fast than that the MJ falls on its face, same thing when trying to give it some fuel heading up bigger hills. If I floor it it just dies like it is running out of fuel and if I keep the pedal down it never seems to recover, if I back off it will pick back up. Been having issues with the IAC but don't think that would cause this problem. Just for some back ground, fuel tank, fuel pump, fuel filter, and all rubber lines have been replaced in the last three years so I shouldn't have any issues there. Only think I did differently recently was dump some fuel into it out of a can in my garage. Fuel was from earlier this spring but was treated with Stabil and SeaFoam and has been being used in my lawn mower all summer without issue. Wasn't that much either, maybe a gallon, then topped it off with about 8 gallons of fresh mid grade fuel. Any ideas what the issue is?

Update: Went to the Dr. last Monday to be sure I was OK. Was checked out and they say I am fine, other then the typical pain for any shock like that. No back or neck issues, Dr. said if there was any questions if I had more server injusries she would be sending me for more tests but she said she is confident that there is not serious damage and wants to follow up with me in a few weeks to look me over again. Some said I must have had someone looking over me, and yes I believe I did., I could be in much worse shape. Still not 100% back to normal but feeling so much better. I have been fighting with the insurance company every day and not making any progress. Had them revalue the truck and it came back even less, not willing to work with me at all. On the advice from a friend of my dad's who owns a body shop I called the adjuster who wrote the estimate. Told him where I was at and want I was hoping for (clear title). 20 minutes and two calls to his supervisor later they will be cutting me a check for $1800 and I will keep my truck with a clean title. I got lucky and had an adjuster who is a car guy and understood what I was going through. Just got a call from the girl assigned to my claim and she said they will be sending out the check and I will have my check in 5 business days. Would have I liked more money, sure, did I get a fair settlement, yes, did I do it on the 100% up and up, yes, I would not have done it any other way. At this point I think the only way this could have turned out better is if it hadn't happened at all but it took a lot of time and effort on my part but I am glad I didn't give up. Tonight when I get home I can actually start working on my truck, of course I am in the middle of installing Torch Height Control on my Torchmate CNC plasma table so maybe I will finish that up first and wait until my check has arrived and then decide is I am going to repair the bed or just build a new one, I saw a really nice looking fabricated bed on this site and my just go that direction.

I am planning on doing the repairs myself, nobody touches my cars but me unless absolutely necessary (inspection, etc). This is not major repairs, the total it due to the age of the truck. The difference between you XJ and my MJ was the loss was your (your wifes) fault, if I had wrecked the truck it would be a shame on me kind of deal and I would deal with it. In this case I was at a complete stop at a construction zone, it wasn't raining, foggy, or dark, and I was visibile for at least 100 yards, maybe more and this guy still managed to smash in to me. I am not taking a loss due to someone elses mistake if at all possible.

Thursday morning on the way to work I was stopped at a cronstruction zone when a guy in a work van was not paying attention and hit me at 35-40 mph without even slowing down. The bed and tailgate are trashed but it seems like the vans bumper went under the Comanche's bumper and the major impact was not on the unibody frame rails. I was able to drive the truck home but the insurance adjuster was here yesterday and is sure they will total the truck. It is a 1988 in fair condition and has 140,000 miles on it so I am sure they are going to try to screw me on what it is worth. I spend 6+ months getting this truck into a reliable condition and my 2 year old son loves the truck, he talks about "daddy's blue truck" all the time, now it sits in my shop smashed up. Here are my questions, has anyone every dealt with having their Comanche totalled due to the age even though it was very repairable. I am not expecting to get $5000+ for thsi truck even though it is worth that to me, but I would like to see $2000-$3000 plus the cost of having to buy the truck back from the insurance company. I just have a fear of them wanting to give me $750 and wanting $250 for me to buy it back from them. What can I expect as an offer from the insurance company both for the value of the truck and for the cost to buy it back and what can I do to make sure I get the maximum amount for the truck. I am not looking to rip the insurance company off or do anything not 100% honest, I just want a fair price for my truck. I know I don't need to tell you guys how rare these trucks are and how hard it is to find something in decent shape. I my opinion they should give me what it would cost for me to replace the truck, not what some stupid book says its worth. Any suggestion when dealing with the insurance company. My second questions is does anyone have any suggestion or know where I can take some measurements to see if the unibody/fame is bent? Like I said I drove it home and it seemed to drive OK but before I start trying to repair the truck I want to try to figure out if I need to have the chassis pulled to straighten it out. I am sure at some point there was documentation that was used by body shops when these trucks were newer when repairs were needed to be sure the chassis was straight. Any help you can give me would be greatly appreciated. I love this truck and had every intention of passing it down to my son when he is old enough to drive, I am sick about this.

About half the time I start my truck it idles very high, or maybe I should say revs very high becuase it is way above an idle speed. It does this for what seems to be a random amount of time, never seems to be the same. Once it drops down to a normal idle speed it doesn't do it again until the truck has been shut off and restarted. Doesnt seem to make a difference if it has be sitting overnight, or for 10 minutes, the whole issue seems very random. Any idea what could be causing this. This truck seems to be the king of random problems. I have a random problem with the radio (aftermarket) also. It always comes on just fine. The display and all of the controls work without issue but I get no sound. The I will hit a bump and the music starts playing. but it isnt just bumps. Right turns, left turns, bumps, hitting the brakes, pressing in the clutch, all of these can cause it to come one or shut off. I am ready to tear the whole stereo system out and replace it all, I just don't have time.

Money actually isnt that bad, my wife works at the daycare center so we get a VERY good discount. Time is the biggest problem, but I have too many project going at once so that is my fault. Kids go to bed between 7:30 and 8:00, I am usually headed to my shop by 9-10 and the I work until I am tired. Usually midnight or so, but sometimes 2 or 3am if I get into something and loose track of time. Currently I am working on our boat, the boat trailer needs some welding done on it, building a stand for my smoker, dialing in my CNC plasma table, and building a water table for the CNC Plasma. That's just what is currently in progress, not what is sitting around waiting for my attention, but the "too many projects" syndromn is a problem I had way before the kids were born.

It was the CPS, well sort of. I started under the hood to unplug the sensor and check for corrosion. When I did I noticed the wire to the sensor was laying again the exhaust manifold. Pulled the wiring away from the manifold, hopped in the truck and it started right up. Looks like the wiring had melted and was shorted against the manifold. For a temp fix I wraped up the melted section with electrical tape and wire tied the wiring away from the manifold. I have a CPS and I'll swap it out in the near future as soon as I can move the CNC project I am working on and use my lift. Thanks so much for the help. I just have so much going on right now and very little time.

Well since we are 2 for 2 with the CPS and this site seems to be very knowledgeable I will pick one up before I go home tonight, I checked online and they are only about $30. Is a CPS failure on these trucks common? Should I have one in my spares for the truck and carry it at all times?

OK I will start by saying this happened this morning when I was leaving for work, I didnt have time to mess with it so I just jumped in my ZJ and headed for work. I will tell you what I know and hopefully someone can give me idea on where to start, I don't have alot of time and I need the truck running. Truck ran fine last night and has not given me issues for quite a while. 1988 with a 4.0 (renix), manual trans. It has been running great, consistanly getting over 18mpg, just filled the tank yesterday. Every now and then it would seem to stall but fire immediately and keep running, this happened maybe 3 times and in the last 5 months. This morning it would not start. It cranks over fine and plenty fast. I can hear the fuel pump run when the key is cycled, but no fire. It is odd because everything was fine, so it seemed, last night when I got home from work, this morning, no love. I will start by check fuel pressure and spark later tonight but I was hoping that someone here could give me some common issues that could cause this to check out. I have 1 year old twins and very little time to mess with this and help you could give me would be greatly appreciated it. I will update this thread when I have more details, fuel, spark, etc. I have the Renix manual that I downloaded off of this website which will probably be a great help. Any deas? Any ideas?

Thanks everyone for your help. Got the new tank installed last night, simple, easy, quick, and cheap. Drove the MJ to work today, no issues. I guess I am back up and running until this tank breaks.