97 97 Bonneville rough idle after start then runs fine.
First post on this board maybe you can help me out.
So a little history of the problem. Car was becoming hard to start, it would start up then idle rough,sometimes it would stall out and sometimes it would catch and run just fine. About 2 months ago during a bad snowstorm, was stuck in traffic for 2hr or so and car started to idle rough then stalled out. Would crank just fine then it would try to start but would just fall on its face. Let it sit for an hour and it started up and ran great. Couldn't repeat the problem until I discounted the battery and I ran into an air mix actuator problem.(thanks to this forum I have rigged it until summer) I was trying to re-learn the actuator and by doing this I was doing a lot of starting and short trips, during this process I let the car idle awhile and I started to get the rough running symptom, I shut the car off and couldn’t get it to re start until the next morning. (The same symptoms where present as described above) I did however get a Bank 1 lean code. Now the car will start fine sometimes and other times it will start and does not want to idle. It seems to be searching for the idle but when it finds it it surges to 2krpm then drops down and idles normal and runs great. I have noticed that if I do a short crank and it doesn’t start than the problem will occur, if I give it a long crank then it will start normal most of the time. The SES light went off after the required 3 cycles and has not returned.
I have changed the IAC, plug wires,and fuel filter. About 6 mouths ago the UIM failed, so I changed the UIM,lower gaskets,plugs and cleaned the TB.
Any help will be appreciated.