I have a 1996 Toyota Camry. It has roughly 118000 miles and a brand new radiator (the car was steaming). It has recently started acting up during cold starts, especially after I have not driven it for a few days. The engine will start, but the idling is very rough for about 5-10 minutes. While the engine shaking is going on, the car has a hard time shifting gears and accelerating, but eventually the problems stop as the car warms up after the first 10 minutes or so. If anyone can help me in diagnosing the problem I would be really happy.
When the car overheated, it is very possible that the head gasket became breached. If that is the case, then perhaps coolant leakage into the cylinders is causing rough running of the engine until it warms up. I would suggest that you have a mechanic do both a compression test and a cylinder leak-down test in order to determine if you have a head gasket problem.
By the way–when was the last time that you checked the coolant level?
If it is low, despite a new radiator, that is an indication of possible head gasket problems.
There are probably two dozen things that could cause a cylinder not to fire when the car is cold including fuel delivery problems, a cracked head gasket, perhaps a small vacuum leak, possibly an EGR valve that is stuck partially open. But I think the most likely might be a spark problem that goes away as the coil and spark plug wires warm up.
Do check the coolant level as VDC driver suggests and check for more exhaust smoke on startup than other nearby cars have (a little can be normal if the humidity is high). But otherwise, I’d check for spark with the engine cold, and maybe fuel pressure although that probably isn’t as easy to check as one might wish. You can try replacing the fuel filter if it hasn’t been replaced for a long, long time (and if there is one outside of the tank which there probably is). If the problem is fuel, filter replacement might help even if the actual problem is elsewhere in the fuel delivery system.
Have you determined the cause of this? I am having the same problem. Thanks.