CManche Posted October 25, 2020 Share Posted October 25, 2020 I recently started working on my 1987 Jeep Comanche 4.0L again and so far I have replaced the crankshaft position sensor, transmission shift cable, spark plugs, plug wires, cap and rotor, fuel tank, fuel pump, fuel filter, and fuel pump relay. Now that I have all these things replaced I was getting ready to get it running and after multiple attempts it would fire sometimes, other times not when we would spray engine starter into the carburetor. We then took one of the spark plugs out to see if we were getting spark and turns out we weren't!!! Before this we checked the fuel injectors and they were all working perfectly, the pressure was amazing on the fuel rail as well, so we knew it wasn't a fuel issue like other people have said it could be. Next we checked the ECM to see if it was messed up internally at all and it was perfect as well. So I am at a stopping point right now until I can figure out what is causing NO SPARK! I heard that it could possibly be the ICM, but I wanted to hear from fellow Comanche owners before I move forward. Please Help! Link to comment Share on other sites More sharing options...
jdog Posted October 26, 2020 Share Posted October 26, 2020 what kind of tests have you performed or just shot the cannon at it? is the dist. turning when you are cranking? do you have spark at the coil? do you have power at the coil? Just trying to establish a base for which way to get you started Link to comment Share on other sites More sharing options...
Limeyjeeper Posted October 26, 2020 Share Posted October 26, 2020 Check the continuity of the harness wire that plugs into the distributor pickup. That wire often fails. Link to comment Share on other sites More sharing options...
MiNi Beast Posted October 26, 2020 Share Posted October 26, 2020 fuel check. spark maybe....confirm where no spark or no spark with fuel. says maybe fire? carb gummed up? so 2.8l? I'm lost. fires with fluid so has spark? fuel air and sparks to run. all three to be worry free. not runnen, no more funnen, time to double check, your last fix it specs. Link to comment Share on other sites More sharing options...
CManche Posted October 27, 2020 Author Share Posted October 27, 2020 @jdogI don't know I will have to check if the distributor is turning and if we have spark at the coil, but I will get back to you when I do Link to comment Share on other sites More sharing options...
CManche Posted October 27, 2020 Author Share Posted October 27, 2020 @LimeyjeeperWhen I was looking over at the distributor I didn't notice anything wrong with the wire but I will take a closer look at it Link to comment Share on other sites More sharing options...
jdog Posted October 27, 2020 Share Posted October 27, 2020 5 minutes ago, CManche said: @LimeyjeeperWhen I was looking over at the distributor I didn't notice anything wrong with the wire but I will take a closer look at it You might have to pull the cap to see Link to comment Share on other sites More sharing options...
cruiser54 Posted October 29, 2020 Share Posted October 29, 2020 On 10/25/2020 at 7:41 PM, Limeyjeeper said: Check the continuity of the harness wire that plugs into the distributor pickup. That wire often fails. Just an FYI, the Renix Jeeps will run even with that harness unplugged. Link to comment Share on other sites More sharing options...
cruiser54 Posted October 29, 2020 Share Posted October 29, 2020 On 10/26/2020 at 7:32 PM, CManche said: @jdogI don't know I will have to check if the distributor is turning and if we have spark at the coil, but I will get back to you when I do Have you ever visited my website? Lots of good info there to help you. Tips 1 through 5 are a must. Link to comment Share on other sites More sharing options...
AzManche Posted November 12, 2020 Share Posted November 12, 2020 Any updates on this? Just curious because I am having a similar issue on a 87 2.5l rennix MJ. I am finding my reference voltage is all over the place. Actually the only sensor I am seeing 5v is my MAP. Have you checked you ref volts? I ran through Cruisers 1st 5 and really thought I struck gold when I found a chasis ground cut from the rear head stud and moved to a valve cover bolt ...no such luck on any changes. Before I get tunnel vision on the ECU i want to throughly diagnose th system. Not to hijack your thread just curious to compare. Link to comment Share on other sites More sharing options...
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