1993 grandcherokar with 4.0L.. Keeps dieing...

Spanaway Mudder · Apr 7, 2011

My works rig that I use for installing.. Keeps going thru Crank Position Sensors... ALL of the sensors have been replaced, including the fuel pump...

Last week it died on me so I got it towed home... Yesterday I replaced the CPS with the 10th 1... 1st one I did tho...

fired right up and no problems... made it about 5-10miles away and there it went again with that dieing ****.... would fire back up, then die... did that probably 4 times before I just let it sit for a bit, then fired it up and reparked into a decent spot.. let it sit for 20 mins....

A friend showed up and disconnected the TPS and it fired up no problem.. but then it wouldnt down shift or anything so I plugged it back in and disconnected the battery terminals and let it sit for 5-10 mins while it reset...

tired of waiting in the cold I hooked it all back up and it fired right up like nothing happened.. when running, it runs top, nice strong drive train (figuratively speaking)....

Well today I go out to it to head out for some work and there it goes again with its not wanting to stay running **** again.. fired it up, was situating the inside for my dogs, walked around to get in it and it died... acted like it wanted to fire back up a few times, but wouldnt do it...

basically we have come to the conclusion that either we find a ECM for it or part it out.... I need it for WORK....... soooo..

PLEASE HELP!!!!

Bill · Apr 7, 2011

sounds to me like a bad plug or a wire shorting out somewhere...

crash2 · Apr 7, 2011

Bill said:
sounds to me like a bad plug or a wire shorting out somewhere...

How is a spark plug or wire going to cause the issue he has?

Gabe you need to start with the basics otherwise anything is going to be a crap shoot.

Start with spark, injector pulse and fuel pressure and go from there.

Bill · Apr 7, 2011

crash said:
How is a spark plug or wire going to cause the issue he has?

Gabe you need to start with the basics otherwise anything is going to be a crap shoot.

Start with spark, injector pulse and fuel pressure and go from there.

not a spark plug duh...an electrical connector

Spanaway Mudder · Apr 7, 2011

The other day, I swapped out coils from my 91 xj... nothing....

yesturday we swapped out CPS's and it ran for a bit.. then today like said above, ran for a short bit then died.. well I just swapped out my coil again and it fired right up.. The owner said that he was told that cps's have been known to kill coils... I dont get it, but the bastards running so, life is good for now...

zukkev · Apr 7, 2011

You haven't mentioned whether or not the check engine light being on when it is running...
Check very closely for a loose ground on the engine block....(back behind the distributor IIRC-mounted to a stud off the side of the block). Poor grounds will kill electrical components repeatedly...., and also check the wiring going from the CKP sensor up to the harness plug on top of the intake...the wires have been known to fall out of the trough that keeps it off the exh manifold...and melt. Hope that helps...

junkyard jim · Apr 8, 2011

If the bad ground doesn't cure it (and making sure the battery isn't loose) then the ASD relay or the connector to the fuel pump may be acting up (happens a lot on Caravans too) Aside from that, there was a harness replacement for the CPS (I still have one around here someplace for a '90 XJ)