Get the computer read and get the trouble codes on the car. research what the codes mean. I would lean more towards an electrical issue and sensors not working correctly, which inturn would throw off the idle and starting. A lot of times its not the engine i.e. pistons, rings and valves, but the support system i.e. electrical and vacuum system sensors, that are not functioning correctly. One bad sensor could cause the Idle Control aka Idle Air Conrol to not respond correctly. Remember all sensors serve a purpose and were put on the vehicle for a reason, find the reason and check that system.
After rereading your post, your EGR valve might be stuck open. the EGR remixes exhaust into the Intake Manifold to get reburnt. Try taking off the EGR valve and just covering up the exsisting port in the intake manifold and see if the car runs better. If it does, thats your problem. |