l just purchased a 1995 Pontiac Transport minivan. l have already had it run through a safety inspection and a emission test, which it passed with no problem. However, when the van is first started, and while it runs until it warms up, it keeps wanting to stall out. Once it does warm up, it runs beautifully. It takes approx. 20 min. for the van to warm up and the van to run properly. l have also filled it with high test gas, and added a fuel injection cleaner to the tank. It helped, but did not fix the problem.

So my question is what would cause it to stall until it warms up, and what can l do to fix it??

THANK YOU VERY MUCH!!!

couple possibilities: coolant temp sensor sending faulty data to computer. or small vacuum leak that disappears when engine warms up due to metal expansion. that said, l would check especially around intake manifold for vacuum leaks (when cold) and replace coolant temp sensor, which usually is an inexpensive part.