97 ZJ, cranks but no spark...
 

hello everyone, a friend of mine picked up a 97 Grand Cherokee 4.0 automatic with 273000 miles for super cheap with only one problem, no spark from the distributor.

He has replaced all the spark plugs on a full tune up replace distributor coil, crankshaft position sensor, ASD relay. None of which has worked. With the key switch turn on the ECU self tests all idiot lights come on and go off in sequence, no check engine light no diagnostic codes. Engine turns over just fine just refuses to ignite. You can hear the fuel pump cycle as well.

Looking for advice on where to look next, he can't afford a "real" mechanic and is currently down to only one vehicle for his family to get to work and kids to school etc

Thanks in advance

Usually a bad CPS or coil are the #1 reasons for no spark. If he just used a cheap parts store CPS that might be the problem, try and find a Mopar one either new or a good used one just to see if that's the problem. The video in this thread is for diagnosing a bad CPS:

https://www.cherokeeforum.com/f2/eng...-start-136974/

There's other things it can be too though... bad ECU, missing/bad ground(s), sloppy timing chain, worn cam/distributor gear, etc.