mica Posted January 23 Share Posted January 23 I had my Comanche parked next to the log deck I was cutting firewood out of, and the rodents struck again. This time they ate the distributor wires flush with the distributor and the wiring that goes to it. To the point I can't find a trace of the wires that lead to the distributor. I am going to order a new distributor, but I need to figure out where the distributor wires come out the the harness. Does anybody have a picture or description of where to look to find the distributor wiring in the harness? Link to comment Share on other sites More sharing options...
mica Posted January 23 Author Share Posted January 23 I suppose I could look into where the CPS hooks into the harness and maybe trace it, but I would guess it goes to the computer then the distributor. I haven't pulled up any diagrams yet. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 23 Share Posted January 23 It won't make any difference if you leave it as is. That deal in the distributor is for sequentially firing the injectors. That's it. If the ECU doesn't see that signal, it adapts. No worries. Link to comment Share on other sites More sharing options...
schardein Posted January 23 Share Posted January 23 I don't own a Renix XJ/MJ to refer to, but thought I would look at the '88 electrical manual to see if I could find the answer. I believe the distributor connector is C231. Strange, I can find the connector in the schematics, but I can't find it in the layout diagrams. Link to comment Share on other sites More sharing options...
Ωhm Posted January 23 Share Posted January 23 11 minutes ago, schardein said: Strange, I can find the connector in the schematics, but I can't find it in the layout diagrams. C231 is on the Alternator Harness (A) (not shown but called out on 4.0L Engine Control page). Alternator Harness connects to C105 Engine Harness. Poster needs to create a signature for his vehicle. I think he's running SBEC not RENIX. Link to comment Share on other sites More sharing options...
mica Posted January 24 Author Share Posted January 24 Thanks all 17 hours ago, cruiser54 said: It won't make any difference if you leave it as is. That deal in the distributor is for sequentially firing the injectors. That's it. If the ECU doesn't see that signal, it adapts. No worries. I didn't even think of trying to start it after I noticed the damage. I usually figure no crank position sensor no-spark, I'll have to wander up there tomorrow and crank on it, see if it barks off. 12 hours ago, Ωhm said: C231 is on the Alternator Harness (A) (not shown but called out on 4.0L Engine Control page). Alternator Harness connects to C105 Engine Harness. Poster needs to create a signature for his vehicle. I think he's running SBEC not RENIX. Good call on the signature, updated. Kinda hard to get a decent response when you all have no idea what rig I am asking about. 13 hours ago, schardein said: I don't own a Renix XJ/MJ to refer to, but thought I would look at the '88 electrical manual to see if I could find the answer. I believe the distributor connector is C231. Strange, I can find the connector in the schematics, but I can't find it in the layout diagrams. Sincerely, I appreciate the time you took to look that up. I only wish I had mentioned I have a 4.0l H.O. engine. flat weather pack connector off the distributor. Link to comment Share on other sites More sharing options...
mica Posted January 24 Author Share Posted January 24 If anyone has a picture or description of where the CPS wiring from the distributor goes, I would be grateful. Link to comment Share on other sites More sharing options...
schardein Posted January 24 Share Posted January 24 28 minutes ago, mica said: If anyone has a picture or description of where the CPS wiring from the distributor goes, I would be grateful. I have a 91 MJ and XJ, I can get that tomorrow! Link to comment Share on other sites More sharing options...
schardein Posted January 24 Share Posted January 24 17 hours ago, mica said: If anyone has a picture or description of where the CPS wiring from the distributor goes, I would be grateful. In both my 91 XJ & MJ, the wiring comes out of the distrbutor and goes towards the rear of the engine. There is a small stainless steel clip that holds it to the motor mount bracket, but that is something I added from the 87-90 models. It continues to the rear of the engine, going over the oil pressure sender, and goes into a grouping of two or three other wiring looms, near the firewall. The grouping of looms is also near the place where several ground wires are attached to the rear pass side of the engine block. The pictures below have the distributor wiring highlighted in green. Link to comment Share on other sites More sharing options...
mica Posted January 27 Author Share Posted January 27 On 1/24/2024 at 2:18 PM, schardein said: In both my 91 XJ & MJ, the wiring comes out of the distrbutor and goes towards the rear of the engine. There is a small stainless steel clip that holds it to the motor mount bracket, but that is something I added from the 87-90 models. It continues to the rear of the engine, going over the oil pressure sender, and goes into a grouping of two or three other wiring looms, near the firewall. The grouping of looms is also near the place where several ground wires are attached to the rear pass side of the engine block. The pictures below have the distributor wiring highlighted in green. Thanks so much, I appreciate you taking the time to do that. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 27 Share Posted January 27 schardain is a good egg. Link to comment Share on other sites More sharing options...
mica Posted February 1 Author Share Posted February 1 Putted around on the Comanche a bit this afternoon. Found the missing wire. Out of curiosity I disconnected the fuel line to keep any old gas out of it and cranked the engine over with the distributor (sync signal generator) wires disconnected via rodent, no spark. Could be coincidence. First crank I had no power to the coil, jumped ASD relay and got power the coil. Still no spark. So something on the other side of the coil is holding it up. It was starting to rain hard, so that's as far as I got. I can hear the fuel pump prime and no fuel coming out, so I must have drained it out before it started sitting. I dug out some of my literature for the Comanche, there was a circa '92 Chrysler training manual (student reference book) for 2.5 & 4.0l Sequential Fuel Injection. There is a note written by the technician taking the training course. "'91 and '92 will not run W/O Sync Signal, '93 won't start W/O sync but will continue to run once started. " Figured these pictures might be handy to somebody, someday. Link to comment Share on other sites More sharing options...
mica Posted February 1 Author Share Posted February 1 Tinkered a bit this morning, not long. Mostly out of curiosity I soldered the stubs of the old distributor wires together, now I have spark. So for whatever reason at least on this engine, the sync signal from the distributor is required for spark. I put 5 gallons in the tank and primed the fuel pump a couple times. I could hear the pump run, but no fuel. I have the line disconnected just before the fuel filter, so it is a pump problem. Verified power and ground at the pump just to be sure. Weird thing is I can hear it under prime and while cranking, pump or inlet sock must be full up with junk or corrosion from sitting. So the Comanche will probably sit a while longer until I tow it over to the garage and drop the tank. Link to comment Share on other sites More sharing options...
JeepSchmidt O'Guinness Posted February 2 Share Posted February 2 The connecting hose from pump to feed pipe in the tank is notorious for liquifying if it's not a submersable grade line. Basically it won't stay connencted / hold pressure. Pull the pump assembly and go from there. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 2 Share Posted February 2 Or the internal rubber hose is split, loose or messed up in some other way. Link to comment Share on other sites More sharing options...
mica Posted February 2 Author Share Posted February 2 2 hours ago, cruiser54 said: Or the internal rubber hose is split, loose or messed up in some other way. Grabbed the whole assembly you showed here at the parts store today, so if the weather holds out I'll drop the tank and investigate. Hopefully it is just a hose or something, but figured it wouldn't hurt to have the whole chunk on hand just in case. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 2 Share Posted February 2 good plan. If you end up replacing the hose, make sure you get the stuff that can be submerged in ethanol fuels Link to comment Share on other sites More sharing options...
mica Posted February 4 Author Share Posted February 4 I forgot how easy is it to get at the fuel pump on these trucks, pulled it out and replaced the 90deg hose and test fired it seemed to work ok after smacking it a couple times. put it back in and it pumped for a second and quit. Pulled it back out, changed the pump/ pickup screen... clearly the wrong pump, but it works. Truck runs again. Looks like the pump was just gunked up with ethanol fuel crud. Any more work on the rig will go to my build thread. If I can call it a build thread, more like how to resurrect a Comanche after it gets abandoned in the tree row, repeatedly. Thanks all for the help, this thread will end here. So great to have a community of experienced folks willing to take the time to contribute to the knowledge commons. Link to comment Share on other sites More sharing options...
mica Posted February 4 Author Share Posted February 4 Link to comment Share on other sites More sharing options...
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