When the car has been off for over 5 to 6 hours, it takes long to start up again. Sometimes, I turn the key, and it tumbles for 10 to 15 seconds before it starts up. When it does start up, it backfires at all RPM's until the engine is warm. I'm guessing it's a bad EGR valve. Is there a way I can test the EGR valve? What else can cause these problems? Thanks for your input.

 

Well, this is what you can do is remove the EGR valve, then what you have to do is apply vaccum to the EGR valve and see if it opens or not. It's a very good possiblity that either your EGR valve is stuck open, has a weak spring, or so the exhaust is forcing it open. If it was stuck closed, you wouldn't have that problem, but you will have some emissions problems. To the sound of it though, the EGR might not be the problem. First thing to start with is a good old fashion tune up and timing check. Replace the plugs, wires, cap, rotor and check to see if your timing is where it should be. Next thing to check is your ECU. When you have performance problems like that, your ECU is the best way of locating the actual problem.

S