maddmatt Posted October 13, 2007 Share Posted October 13, 2007 hi, I have a 87 Comanche 2.5 TBI 4 speed auto. I have replaced the spark plugs , plug wires, cap, rotor and the crank position sensor. The truck cranks over but still will not start. It all started when I was driving ,the truck would shut off (cut out) but keep running untill I parked it and ever since then it will not start. Any info would help me out greatly, thanks. please help, Matt Link to comment Share on other sites More sharing options...
jtdesigns Posted October 13, 2007 Share Posted October 13, 2007 hi,I have a 87 Comanche 2.5 TBI 4 speed auto. I have replaced the spark plugs , plug wires, cap, rotor and the crank position sensor. The truck cranks over but still will not start. It all started when I was driving ,the truck would shut off (cut out) but keep running untill I parked it and ever since then it will not start. Any info would help me out greatly, thanks. please help, Matt Do you have fuel pressure? Link to comment Share on other sites More sharing options...
optichris Posted October 13, 2007 Share Posted October 13, 2007 you need three things for the engine to run...spark, fuel, and air. Check these and you will probably find one of them missing. Usually, it isn't the air. You can check the spark by pulling a spark plug wire slightly off of the plug and see if you have spark. If you suspect fuel, you can put a couple of drops in the intake and see if it starts. There are a couple of ways to diagnose a no-start, these are just suggestions. Link to comment Share on other sites More sharing options...
maddmatt Posted October 13, 2007 Author Share Posted October 13, 2007 I have fuel and air, NO SPARK! this jeep is drivin me crazy. I'm about ready to scap this truck! anything else i can do for no spark? thanks for the help' Matt Link to comment Share on other sites More sharing options...
Pete M Posted October 13, 2007 Share Posted October 13, 2007 Chances are good it's the CPS, but you should probably start at the cap and work backwards with a multimeter to see where the spark electricity stops (if it's starting in the first place). The computer won't fire the sparkplugs unless it's getting a good solid signal from the CPS (it's located on the bellhousing and senses notches on the edge of the flywheel and sends a signal to the comp telling it where the engine is in it's cycle). Link to comment Share on other sites More sharing options...
maddmatt Posted October 13, 2007 Author Share Posted October 13, 2007 I just put a new cps on it last night Link to comment Share on other sites More sharing options...
martywarner Posted October 14, 2007 Share Posted October 14, 2007 the same thing happened to me it ended up being the computer. same year engine mine is a 5 speed its for sale by the way marty :Canadaflag: Link to comment Share on other sites More sharing options...
FxRacing282 Posted October 14, 2007 Share Posted October 14, 2007 check the wires coming off your distributer. my chevy died when one of the wires went to hell Link to comment Share on other sites More sharing options...
maddmatt Posted October 16, 2007 Author Share Posted October 16, 2007 thanks, i'll check and let yins know what I find. I had to take a break from working on it , before i ended up flipping out! Matt :wall: Link to comment Share on other sites More sharing options...
Oizarod115 Posted October 16, 2007 Share Posted October 16, 2007 my buddy was talkin earlier about his friends YJ they spent hours trying to fix it throwing parts at it, and turns up it was a fuse under the hood that acts like a kill switch. this was an HO 4.0 so i didnt know if our trucks have the same type of fuse? Link to comment Share on other sites More sharing options...
FxRacing282 Posted October 17, 2007 Share Posted October 17, 2007 you are talking about the fuse covered by metal? if yes once they cool down they will work again and I'm pretty sure XJ's and MJ's had em. Link to comment Share on other sites More sharing options...
maddmatt Posted October 18, 2007 Author Share Posted October 18, 2007 anyone have a pic of where that fuse is? or a little more detail about where it is at? thanks Link to comment Share on other sites More sharing options...
optichris Posted October 18, 2007 Share Posted October 18, 2007 Matt, You may also want to check out the ignition coil. You can check the internet for more information, but generally this is how you check it: Take the coil out of the truck. Check for continuity on the primary and secondary sides of the coil. Do this by taking a ohm meter and putting one lead on the + pin and one lead on the - pin. You may have to unscrew the coil from the base (module). If the tester says infinite resistance, you have an open circuit in the coil and it is bad. If you have zero resistance, you are ok and can move to step two. Step two is a similar procedure, but this time have the one lead on the - pin and one lead on where the spark plug wire connects. Same test here, if zero resistance you are ok. This is a quick test that you can do that is free. It could be that your crank position sensor is fine, but your coil is bad. My advice: Check everything you can check before you throw any more parts at it... Link to comment Share on other sites More sharing options...
maddmatt Posted October 20, 2007 Author Share Posted October 20, 2007 Ok , I'm going to check that today and I'll let u know what I find. Thanks, Matt Link to comment Share on other sites More sharing options...
maddmatt Posted October 22, 2007 Author Share Posted October 22, 2007 I pulled the coil off today and everything reads ok with the ohm meter!! I still have no spark, I don't understand? Anyone have anything else for me?? please help! Thanks, Link to comment Share on other sites More sharing options...
Wildman Posted October 22, 2007 Share Posted October 22, 2007 Here, check out this site, there is also the Cam Position Sensor located in the bottom of the distributor that will kill spark. And as sugested, you might want to trace down each wire to find the problem. http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm CPS info is about half way down the page. Link to comment Share on other sites More sharing options...
FxRacing282 Posted October 22, 2007 Share Posted October 22, 2007 make sure your wires arent burned up! Link to comment Share on other sites More sharing options...
maddmatt Posted November 8, 2007 Author Share Posted November 8, 2007 well i cut the wires for the plug and wired it in directly and still the same. I have had it with this truck. Link to comment Share on other sites More sharing options...
maddmatt Posted November 8, 2007 Author Share Posted November 8, 2007 FOR SALE!! It has a jasper remanufactured engine installed in 2000 also installed a new gas tank and sending unit. runs great (if it would start) it has had regular maintenance done on it, including emmissions and I have all the reciepts of all the work done. I hate to get rid of it but it does me no good sitting in the garage. It is a 1987 with a 2.5 4 speed auto 4x4 short bed. looks rough, need body work or new bed. The engine was installed in 2000 and cost over $2,000. The gas tank and sending unit was installed in 2003 and cost over $600. I have all the reciept for everything done. Link to comment Share on other sites More sharing options...
feerocknok Posted November 8, 2007 Share Posted November 8, 2007 Where are you at? Link to comment Share on other sites More sharing options...
Pete M Posted November 8, 2007 Share Posted November 8, 2007 You're going to plop this in the classifieds then, yes? Link to comment Share on other sites More sharing options...
maddmatt Posted November 8, 2007 Author Share Posted November 8, 2007 I live about 40 min. north of Pittsburgh, Pa. Link to comment Share on other sites More sharing options...
feerocknok Posted November 8, 2007 Share Posted November 8, 2007 I live about 40 min. north of Pittsburgh, Pa. I'm sorry to hear that you're giving up. And also that you're not close to me. Sounds like it just needs a bit more work... Link to comment Share on other sites More sharing options...
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