1989 jeep grand wagoneer V-8/360



runs very rough/dies when engine is cold. as engine warms up, it runs fine

any idea where to look for a solution?


Could be a fuel/air mix fault.

Perhaps the engine temp sensor (if so equipped) is giving the computer the wrong info.


Is it carburetted or fuel injected? Sounds like a carb with a bad choke pull-off…


When you start the car the choke plate in the carb is completely closed. When the car start the choke pull-off opens the plate about ~1/4". If the plate doesn’t open, the carb doesn’t get enough air and the engine is going to run real rough. As the engine warms up the choke will open the choke plate normally. Rochester (GM) had a vacuum diaphragm on the carb to do this. My 83 Mustang GT’s Holley carb used a metal housing with a brass piston that used to stick all the time.

Here is a link for carb troubleshooting.

Ed B.