I have a 1990 Trooper with V6 2.8l engine with automatic transmission. Just recently had both head reconditioned at machine shop and one head replaced due to it being cracked. Check Engine Light would come on for a couple of minutes of use and go off after a while then come back. This problem occured even before head work. Also noticed some sort of vibration type noise in the transmission wich would only go away when the revs drop or next gear kicks in. Any ideas as to what is going on?????? Also this Trooper was bought used and major work was needed because the mounts for the power steering and alternator where broken and lots of inventing was put in place to make engine work. All those mounts where replaced at same time head work was done.

 

The tranny problem went away when I added a quart of trans oil since it was low. The check engine and smoking whent away when I added stop smoke to the engine but a few weeks later the check engine came back on. Its hard to find anyone who has the engine reader for old fuel injection models.