Your description of the symptoms are not very clear so correct me if I am wrong.
You mean the engine surges at cold start?
Idling is very low after warming up?
August, 4, 2009 AT 5:18 PM
initially it started with engine trying to stop on coldstart ( the dial tries to return to 0 and fluctuates) this picks up and stabilises after 3-4minutes and then runs normally thereafter
Now, the engine slows down and seeks to go off when it is hot maybe on traffic and more when on AC,
my mechanic is saying it should be one of the cylinder valves that needs re-grind or replacement. Please advise I have changed the fuel pump severally without any use
August, 5, 2009 AT 8:23 AM
During cold start the idling speed should be above 1000 rpm and in your case it seems to be below that.
Replacing the fuel pump is not gong to help. The 2 possible causes are : 1. The idle control system is malfunctioning. It could be a faulty or clogged IAC and/or throttle body. If the Malfunction Indicator Light ( MIL) is not showing, it would most likely be clogging or a stuck IAC valve and this problem can be rectified by cleaning the throttle body and IAC.
2. Compression leak. This could be caused by valves or a bad head gasket. If it is a bad head gasket, it would normally be associated with coolant losses or overheating.
If it is valve leakages, a compression test should be able to show something. Chec the valve clearances to see if any are too tight.