Pontiac Repair: 2.2 rough on cold starts, coolant temp, engine coolant

Question
1996 Sunfire, 2.2 auto., 225k. Trouble starting cold and runs rough, but within
minutes it settles down and runs good at operating temp. Repairs made, plugs,
wires, throttle body and idle control cleaning, fuel injector cleaning, new fuel
filter. No engine light on either.Thanks

Answer
Hi Kevin:

With that many miles on the car it can be just about anything.. It's not going to run like a new car. The engine is more than likely tired! but things to look at are bad ground connections on the body and the block. The transmission bolts have a few ground wires on them take them off and clean them. I would take a look ath the fuel pressure when the engine is cold. It may be a few pounds low and that cause an issue. Just because it has a new filter doesn't mean the pump is good. If you have a scan tool I would pay perticular attention to the coolant temp and engine coolant temps at cols start they should be the same. I wouls also suggest trying a product called top engine cleaner. it is a carbon blasting material that will clean deposits off the back of the intake valves. They are more than likely carboned up and starving the engine of fuel on a cold start. I would get 2 cans and run it through the engine and see if that helps. You have to run it through an vacuum line on the engine and run it through at a pretty quick pace and let the engine slall out on the second can and let it sit over night. It will start really hard the next day but the longer it sits in the engine the beter job it will do. Good luck :}