Use brake cleaner it will work better for the tar crap. Also make sure that the connections aren't corroded. Also use a mini drop cloth to catch all of the crap from the C101, it is quite messy, you don't want it everywhere.

 

Well still no spark clean all the grounds of the jeep, put new fuses clean the c101 put new coil and new module new crank sensor. I'm at a end here

 

is it cranking just no spark?

 

Is cranking but no spark and now it stop cranking as we speak but all my dial are working

 

Well, clean battery terminals, charge battery/get a jump, jiggle the shifter in park and neutral while holding the key over on start. Whatever it takes to get it to crank!

Then find a digital meter and check the CPS output as explained in Cruisers stuff, or here in post #2 in this thread.

I know it's new, but still, seeing the signal at the connector is next I think. Jeep actually made and sold a "bypass harness", to send that signal straight to the ECU. That's how important it is.

Hopefully Cruiser will chime in if I'm on the wrong track!

 

Finally took it to a electromechanic the jeep computer die

 

Might as well put one in from an 89 or 90 to get the extra HP while you are at it then.

 

I can use one of those on my 87 whit out any change

 

Yes:
"If you're going to the JY, get one out of a 1989 or 1990 with the part number ending in 428. "

I'd see that the correct pin on the ECU is getting a signal from the cps, and not it's firing before I bought a new one though.

 

Don I love your deck screw mod! And yes check the vtage to the icu. Don cruiser and I had this same issues with my jeep last two weeks or so. Everything worked right just no spark. I out a junk yard icu and coil in it and it now runs like a raped ape

 

I think it was your thread that "inspired" me on that Kris. I'm putting together a You-Tube with exactly what to buy at the dollar store, and how to get at the Led, and it's polarity. Oh, and I won't be grounding it on the battery with a screw. I suppose even that could make a spark! Cruiser is suggesting I check at the diagnostic port. I will, If that don't light the light, it should after just unplugging the rear yellow 5v.

Always, with cables, or anything else, make the last connection a ground that is not near the battery.

 

Update on the jeep the computer is completely Fry. We talking mmmm.mm.mm toasty. I'm going through all wires to check if there's any cute and burn wires to mount a use computer

 

Well. News I got a new ecu for my Xj and no progress I'm thinking on getting rid of my Xj if I can't start it . i bought new ignition module and coil new crank sensor all Mopar. Paid electromechanic and nothing no start and to make life funny just got laid off. I'm at a end this jeep has suck most of my saving please help me I have done all on the treads you guys have share

 

Was it you, in a different thread that did the c-101 bypass, soldering the wires? Sorry Btw. Both a broken rig and getting laid off sucks. It IS possible to check right at the ECU, for the CPS signal. I don't know which pin it is.

THEN I've been experimenting, With a 3.5 volt, Led bulb, it seems possible to check the ECU signal to the ICU. (it's the rear, 5V yellow on there). See here. (the led is polarity sensitive, only works one way).

 

Saw it did it no signal from the coil and injectors.. Its like its dead it just crank