I have a 96 Grand AM with 90,000 miles on it. The engine runs rough when cold and the engine light blinks. After about 5 minutes the engine runs fine. The engine light stops blinking (but stays on). On warm days this doesn't happen. Only cold days.
I took it in for a diagnosis. The garage ran the computer diagnostics. They replaced fuel injector one. They also replaced the gasket for the intake manifold.
This worked OK for about a month. But I think it actually worked OK because the weather warmed up. Now the problem is happening again.
I took the car back to the garage. They told me it is running OK and the computer is not telling them any incorrect codes. They suggest plugs and wires. I changed the front 3 wires and plugs myself (the problem is still occuring). I am having trouble getting to the back ones. But that is another story... amazing to me that a mainenance item would be so hard to get to...
I am a little skeptical about what the garage is telling me. If the plugs and/or wires were bad why would the car work fine when warm?
I need to take the car back to the garage. Any ideas on what to tell them to look for?
Thank you for your time.
-Richard