I have a 1999 4WD tahoe, 5.7 EFI. For about 2 yrs now the engine every 3-4 weeks will start for a second then quits. Wait a few seconds and it does the same thing. Its like I'm getting one round of spark gas at each start. After 20-30 minutes it will finally run every time. I have been told this sound like vapor lock, but have read that it is not likely in tank mounted pumps. I have also changed the pump and fuel filter this spring and it still does it. Plugs, wire, cap and rotor are new also.

I have a 1999 4WD tahoe, 5.7 EFI. For about 2 yrs now the engine every 3-4 weeks will start for a second then quits. Wait a few seconds and it does the same thing. Its like I'm getting one round of spark gas at each start. After 20-30 minutes it will finally run every time. I have been told this sound like vapor lock, but have read that it is not likely in tank mounted pumps. I have also changed the pump and fuel filter this spring and it still does it. Plugs, wire, cap and rotor are new also.

Have the very same stupid problem. Have you discovered the soloution?

Thanks,

Fred

Does this happen if it sits overnight? Or does it only happen after it sits for a while (like 30 minutes to a few hours)?

It is common for the fuel pressure regulator to go bad and leak fluid into the intake which floods the engine. This can make it hard to start with the extra fuel in the engine.

If you have access to a fuel pressure gauge, you should get a reading when the stalling occurs.

//2000CAYukon

Does this happen if it sits overnight? Or does it only happen after it sits for a while (like 30 minutes to a few hours)?

It is common for the fuel pressure regulator to go bad and leak fluid into the intake which floods the engine. This can make it hard to start with the extra fuel in the engine.

If you have access to a fuel pressure gauge, you should get a reading when the stalling occurs.

//2000CAYukon


Looking at the discription of the problem I don't believe it's a flooding problem. He said it runs for a few seconds and stops. This is the same problem I am having with My 1999 Tahoe. The previous owner had the fuel pump and filter replaced twice and it is still an on going problem. It usually happen when it sets over night. After a couple of tries I let it set for a couple of hours and it starts right up. It's fine for another 3 or 4 weeks. I can hear the pump running in the tank so I don't think it is an electrical problem or a pump problem. I took the cover off of the fuel pump relay and manually operated the fuel pump. I hear a noise on the engine during this time. Is there a bypass valve that recirculates fuel back to the tank? I have ordered a book for the Tahoe but I haven't recieved it yet.

Is the security light on, sounds like it could be a passlock problem