I have a 96 caravan with a 3.8 that when you start it cold acts like it runs on 3 cyls.until you play with the gas pedal alittle, then it picks up the other cyls. It only happens when it's cold, warm the engine starts great and runs fine. There are no codes, and it was tuned up about 15000 miles ago. Can anyone help me?

 

Bomber, I think you're going to need a scan tool for this one. With a problem that is this brief and narrow of conditions, a scan tool will provide you a detailed report of whats going on at cold start up. During cold start the ECM is operating in open loop mode and is utilizing manifold pressure, barometric pressure, coolant and air temperature to provide the correct amount of fuel to the engine. Being your problem is only during cold start, from experience I would be suspect of the coolant temperature sensor. With a scan tool, you could turn the key to the on position and read the coolant temp. relative to the intake air temp. value. If the vehicle has undergone a long cold soak, and the coolant temp. sensor value and intake air temp. sensor value varies by more than a few degrees, chances are one is incorrect, and it would hopefully be obvious which one is correct given the known outside air temperature. Without a scan tool, you could back probe the coolant temp. sensor harness with key on and read the resistance signal, then correlate that signal with a graph from a service manual mapping coolant temp. to ohms of resistance. The scan tool would also allow you to take a snap shot of engine operating parameters during start up when the misfire occurs. You also might be able to record and playback the data later to help determine what sensor values are incorrect. Sorry to get technical, but I hope this helps.

 

Welcome to DF
I agree as well.

 

I'm happy to tell everyone that my problem turned out to be a bad coil pack, Thanks for everyones advice!!!

 

...and a big thanks to you for posting the fix.