buick stalling

I have an 89 with the 4 cylinder engine. When its cold, on a cold start, my car will start really slow and rough. It will run but it sputters a little bit. Like its missing. There is a lack of power. If you go ahead and drive it runs like that for about 20 seconds and then the power returns and it drives just fine. Any thoughts? This only happens when its cold. Once it warms up it is fine. It will start fine with no problem after that.

That 2.5L 4-tech has a distributor, correct? Have you checked the distributor cap when cold for any signs of moisture? When's the last time you've performed a tune up on that car? Even back in '89 GM had some reasonably good diagnostics and supported datastream. If you have a professional GM OBD-I scan tool you may be able to glean some information from monitoring sensor values when cold versus when the power returns.

-Rod

I am going to guess that you have a Buick Skylark since that's the only Buick that had a 4-cylinder engine in it. But you can help by telling us if it is the old throttle body injected 2.5L or the newer port fuel injected Quad-4 2.3L.

I'd first check for a vacuum leak by spraying the TB and vacuum lines down with carb cleaner (probably needs it anyways) while the engine is runningand warm but not hot. When you squirt around the carb base and hoses and the engine stumbles, you've found a leak. After that check the coolant temperature sensor, the IAC (idle air control) valve, and the EGR (exhaust gas recirculation) valve, if equipped. These are common problems when starting cold.

Next, any lingering smoke from the tailpipe when it is cold? Does it smell sweet? Like gas? Like burning oil? With it missing I'd guess it smells like unburned gas. If so, I'd turn to the spark plugs and remove each of them and check for oil fouling or wetness due to fuel or water after the car has sat overnight. A fouled plug can't create the needed spark, so the oil/fuel/coolant leak needs to be fixed.

Good luck!