good morning. I have a 1990 cherokee 4.0 that is stock other than a little lift. it would not start the other morning, it tries to turn over but nothing. it has fuel at the rail but not spark coming out of the coil. I replaced the coil last night and still nothing. what would cause no spark. any thoughts. I appreciate any help. figures it snowed today and I had to drive a 2 wheel drive car.

 

check out your crankshaft position sensor. (cps)

most likely your cause.

 

Did you verify that there is actually no spark? Have you changed any of the rotor and cap assembly lately? If not - thats the first place I'd check

 

#1 suspect for no-spark is the crankshaft position sensor.

#2 suspect is the coil, but you already replaced that.

TEST your crank sensor. And if you have to buy one, I recommend purchasing it directly from Jeep. I have had mixed (poor) luck with aftermarket crank sensors. And even if they do work out of the box, the longevity just isn't there.

If crank sensor checks out, the ignition control module (under the coil) is still in play here...........

 

thanks for all your quick responses. Yes there is no spark coming out of the coil.

The CPS is on the trans bell housing correct. is there a quick way to test if its working.

is the ignition control module the pc the coil clips into. how do you test that? see if there is voltage coming to the contacts.

the CPS was replaced 8 years ago, thats how I purchased the jeep the owner couldnt get it started and let it go for $800.00

 

Check out this thread on the crank sensor. Tells you how to test.

http://www.jeepforum.com/forum/f11/c...ailing-639123/

The ignition control module can't be tested without special equipment. Some parts stores can do it, some can't. Dealer can, but will charge you a bit.....

 

CPS did the trick, what a pain to get to but started right up. thanks for everyones posts

 

Be careful when giving advice: The rotor and cap are AFTER the coil. It is the coil the feeds the 'spark' to the cap/rotor.