I recently bought a jeep country that won't fire up,it will turn over and has power to everything,but no spark. I pulled the wire off at the coil while turning over and nothing there.!! Someone said that it might be the pcm or the ecu. Can these be tested and where abouts are they located. There is some computer looking thing beside the air box bolted to the left fender.?? As for the ecu i wouldn't have a clue where to start looking for that sucker!! Should i be looking in this direction yet for spark or should i be looking in the ignition area??? It's hard to stay on a simple path with electrical diagnosing you just start looking at everything. Anyways is there someone out there that has some experience with this year of jeep it seems there all different.

Thanks,Dan.

 

I would get a code scanner and see if the computer is throwing any codes

 

Will it give me codes with the ignition on??

 

There are a dozen things it could be.

X2 on the trouble-codes.

We can walk you through it, but you will need to learn how some things work along the way. You will also need a manual, test light, and digital volt/ohm meter.

 

CPS.

 

Yes... by all means... let's just start throwing parts at it and hope it runs

 

First thing, the computer looking thing by the air box is the ECU. You should first check to see if the computer has thrown any codes. This does sound like a CPS issue, though. The CPS can be read out with a multimeter and verified bad before you just buy one. Just about all of the electrical parts on the XJ 4.0 can be tested so, definitely don't just start throwing parts at it.

 

first thing you need to do is buy a manual. this will show you all locations of seperate parts. then start testing. throwing parts is great when you hit the part thats broken first, lol....
cps sounds like a great place to start.

 

Thanks for the quick reply guy's!! I just got home and will test out the cps first and then i will go from there. Oh yah I do have a clymer manual for it and it shows the ecu on the fender where it should be but it says that it's for a 91-93 model i thinking that mine isn't a 96 like i thought just got it and am excited so i took the guy's word for it sorry!!. I'll check out the cps and get back to you all.

 

O.k. i went out and checked the plug. I put the meter on 200ohms and there was nothing. I checked it on the 20k scale and there was nothing.!!!! I would tend to believe that it is good. right!!!. i don't have access to a scanner right now is there a way to test the pcm???. should i be getting constant power to coil plug with the ignition on?? i'm reaching for anything here.