Stalling problems on 1997 Grand Cherokee Laredo 4.0 engine
04-03-2013 | 02:25 PM
#1
Thread Starter
Newbie
Joined: Apr 2013
Posts: 1
Likes: 0
From: Tehachapi, CA
Year: 1997
Model: Grand Cherokee
Engine: 4.0
Stalling problems on 1997 Grand Cherokee Laredo 4.0 engine
I own a 97 Grand Cherokee Laredo with a 4.0 engine. It has 128,000 miles and has experienced stalling or just plain quitting while at road speed. Two years ago, check engine light came on, stalled never to refire. Code for crank and/or cam sensor. Had replaced and it ran fine for one year. Check engine light on again. Code for ignition coil. Had replaced and ran fine for one year. Had washer spacers put under PCM cover screws.
A few months ago whole scenario started again but NO check engine light. When first started it ran and idled fine but put under load it would just die. Most of time would restart, drive quarter mile come to stop and die, restart, drive 30 mph and would just quit (very dangerous), pump throttle and for some unexplained reason it would refire. Once warmed up drove for 10 miles and could not get it to stall. What the heck is going on?
I was not going to chase hundreds or thousands of dollars to solve this, so… removed idle sensor and cleaned, cleaned throttle body bore & idle bore, checked vacuum lines. Removed MAP sensor checked and appeared OK, checked throttle sensor, zip tied connectors to PCM. Used LPS contact cleaner (great product) on all sensor connections. Took for test drive…and stalled.
Got thinking, just cleaned and reconnected everything on positive side (+), what about negative (-) side? Cleaned battery terminals, cleaned chassis ground adjacent to battery on upper fender well, disconnected ground gable from block to battery, cleaned and reinstalled. Failed to mention, have a valve cover leak at rear and when checking ground stud on block (between #5 and #6 spark plug) it had dirty oil on it. Dismantled connections at stud and were oil soaked. This is the PCM ground. Cleaned and reinstalled.
Driven car for 100 miles, stop and go, highway and hard braking and NOT A STALL. I could have shortened the blog and just said….CHECK THE GROUNDS!
A few months ago whole scenario started again but NO check engine light. When first started it ran and idled fine but put under load it would just die. Most of time would restart, drive quarter mile come to stop and die, restart, drive 30 mph and would just quit (very dangerous), pump throttle and for some unexplained reason it would refire. Once warmed up drove for 10 miles and could not get it to stall. What the heck is going on?
I was not going to chase hundreds or thousands of dollars to solve this, so… removed idle sensor and cleaned, cleaned throttle body bore & idle bore, checked vacuum lines. Removed MAP sensor checked and appeared OK, checked throttle sensor, zip tied connectors to PCM. Used LPS contact cleaner (great product) on all sensor connections. Took for test drive…and stalled.
Got thinking, just cleaned and reconnected everything on positive side (+), what about negative (-) side? Cleaned battery terminals, cleaned chassis ground adjacent to battery on upper fender well, disconnected ground gable from block to battery, cleaned and reinstalled. Failed to mention, have a valve cover leak at rear and when checking ground stud on block (between #5 and #6 spark plug) it had dirty oil on it. Dismantled connections at stud and were oil soaked. This is the PCM ground. Cleaned and reinstalled.
Driven car for 100 miles, stop and go, highway and hard braking and NOT A STALL. I could have shortened the blog and just said….CHECK THE GROUNDS!
Thread
Thread Starter
Forum
Replies
Last Post
rusty_bucket
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
3
08-29-2015 07:42 AM
Katt Dogg
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
1
08-25-2015 09:03 PM
14lgreer
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
3
08-21-2015 02:46 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)