We put a rebuilt engine from a trooper into my 93 Rodeo. Idles great, no problems. When you shift into Reverse or Drive the engine cuts off. I can't figure this one out. Thanks in advance for any and all help in this matter.

93 Isuzu Rodeo with the 3.1 Liter 6cyl engine, 4 wheel drive.

automatic trans? maybe a stuck torque converter clutch. when it stalls is there any bucking or does it just cut out?

A '93 Rodeo with a 3.1 GM engine, are you sure you didn't mean to state 3.2L Isuzu engine?

The '91-'92 Rodeo's were in fact the 3.1L GM engine; but the '93's and up are Isuzu engines.

If it's an automatic - perhaps a vacuum leak?