Hi all,
looking for any guidance here. Went to start the jeep today and seeing a strange issue. When I turn the key to start it, for a moment it seems to start or at least try. When I let go of the key and it returns to the on position it doesn’t even try to stay running. No cough, sputter, etc, just instantly dies. If I hold the key in the start position and let the starter spin, it will seem to run, not well, but run and increase RPM as long as the key is turned. Seems like it instantly has no spark one the key is released.
Any thoughts?
Appreciate any help
Brent

 

Well, you need to start out with testing systems....
For the engine to run it needs fuel, air and a spark...
You can rent most testers at an auto parts store..
Test to see it you have fuel pressure at the fuel rail....
Then get a $5 dollar spark tester to insure the plugs have spark.
Electrical, test your battery and then clean the battery connectors as well as all the grounds...especially the one by the oil dip stick. Take it apart and use wire brush and steel wool....
refrain from firing the parts cannon.....
We will help you get it going again....

 

in this case I would be working backwards, and see if 12V is emanating from your ignition "on" switch

The presence of 12V at coil, FP relay, various fuses, or anything that is powered with ignition on should be a clue as to whether its the switch

 

Note from DJ about 96 Power Distribution Center fuses

If you have a 96 and want information about the fuses in your Power Distribution Center click on this link and look at Post #3 by Radi
https://www.cherokeeforum.com/f2/pds...iagram-130063/

 

Thanks for the input everyone. This gives me a few next steps.

 

Been testing but no real progress.
cleaned the terminals and grounds.
checked spark with one of the cheap testers.
fuel pressure shows 42 lbs

still getting the same symptom. It actually starts and will run as long as I keep the key in the cranking position. As soon as I release it and it returns to the on position it dies immediately. It seems electrical sine it doesn’t even try to stay running. One thing I noticed is I have 12v at the coil when cranking but not when the key is in the on position. Is that correct?

 

No, the coil needs 12V any time its running

Check if other things that should have 12V with ignition "on" do or do not have 12V.

If they do not, its your ignition switch electrics

If they do, its likely to be a wire or connector

'96 owners should check every fuse imo

 

Success! I hotwired it to prove it was the ignition switch. Went and grabbed one and already have it swapped out. I’m back on the road. Thanks everyone!