I am new here and need some help, I have a 89 Trooper with 199,000 miles, several week ago, it died on the highway, seems alternator failed and did not charge battery, swapped battery, it started and ran fine home, replaced alternator and battery, it will start run as long I hold the key on, let go of the key and it dies or if I hold the key and force feed gas for about 10 sec, it will run for ever, changed ignition switch, problem is the same, replaced something called a resistor bundle and the the problem does not go away. have replaced all fuses related to starting and fuel pump. Not sure what else to do. The RPM's run about 600 to 700 in normal idle.


Mike

I solved my problem with my 89 Trooper. I replaced the alternator again. Runs good and actually better than before. Still have a slow idle problem but I believe it maybe a vacum hose. Only slow idles in Drive or reverse when the Trooper warms up. Plan on changing the therostate also.

Hello,

Sorry for replying from such an old post but I had the EXACT same issure with my truck. It is a 90 pickup with a 2.6 L and about 210 000 km.

It would ususally run fine once i had it running for a while, but when i'd try to start it, it would run as long as i had the key turned over. As soon as i let go of the key, it would lose the spark and die. I never did find out exactly what the issue was but I had it down to a small area. I'm 99% sure that it is one of the main relays inside the fuse/relay box under the hood.

I have pulled out every relay and manually tested
them and they all worked fine. I also pulled the box apart a little bit
to see inside it. Inside the box, is a rat's nest of wires which are
have connections made with solder and electrical tape.

The one thing i found that seems to work whenever I'd get this problem. is I just open my relay cover and wiggle all of the relays (aka...make sure they are all had a good connection) and then start it again. This worked pretty much every time and i'd be off.

One trip, It actually died on me when I was driving. I tried doing my little trick but it didn't work but i found that the main ECM relay (the one that is an orangeish colour and has 6 prongs) was really hot. I pulled it out, let it cool and put it back in. The truck started and ran fine since.

I have since purchased another main ECM relay but haven't put it in because i wanted it fail again to make sure that that is what the problem was. My truck has "magically" been working fine for the past 4 months from no real significant fix. I keep the extra relay in the glovebox in case it dies again and that was the actual problem.

Anyways, just thought I'd share my experience with that issue.

-Greg