24compact

Hi, when I let the truck idle the engine light flashes, when I drive the truck the light will not flash and sometimes it will go away!! Truck has plenty of power runs great when driving but at idle you can feel it missing!!! I have changed plugs,wires,ignition coil! I was thinking maybe fuel issue so I hooked up a fuel pressure gauge and at idle it goes down to 42psi I give it gas and it will go to 48 psi. I have changed the pump twice today with same results, I also changed fuel filter and blow out the lines from fuel rail to fuel filter!! Please help.

oilcanhenry

42 to 48 PSI is too low on the fuel pressure needed. Ideal is 55 to 62 PSI. When it comes to fuel pumps, buy the best you can afford and if it is made in North America, so much the better. You do need to make sure that the fuel pressure gauge is accurate, however.

73shark

Welcome to the forum. Moving to the Silverado section of the forum where you will get more views.

24compact

Hi I bought the

Delphi Fuel Pump EFG0407 it was the most expensive one at AutoZone! Normally Delphi is good! I will get another tester and see if I get a different reading. Do you think it could be the intake gasket? I did spray it with carb&choke cleaner and found no issues! Thank you for the reply I really appreciate it

24compact

I used the same fuel pressure gauge on my 2005 Silverado and the pressure was 55 psi so I believe the gauge is good

oilcanhenry

Good choice! I doubt that it is your intake gaskets after the carburetor- cleaner test. I would guesstimate that you have an EGR issue going on. However, it could also be a fuel vapor system intake issue, or possibly a PCV valve system issue, at this point in time, 24compact.

oilcanhenry

I believe that you are correct about the fuel pressure gauge working properly. I believe that you have an intake "leak" somewhere, as I will discuss further in the post above.

24compact

i changed the intake gaskets today and it didn’t fix the issue. Junkyard time lol

Benderizme

I kept getting a misfire code on my 02 Silverado 1500 2wd ext cab 5.3l and replaced everything and still kept getting the code for misfire , reset computer, disconnected battery, and rechecked everything and still got the code, turned out to be a minuscule crack on fuel pressure regulator vacuum hose, replaced both regulator and hose and it was gone. Wish I would have tried that first, I’d still have money in my pocket, but $10 and Rock Auto and 5 minutes later purrs like a kitten again, hope this helps someone else before they spend a small fortune before finding out like I did. Good wrenching…

oilcanhenry

No, this is fixable. We simply need to diagnosis this issue to the Nth degree, 24compact. Give we who are here long-time a chance to solve your issue. There are lots of people here, with even better at Dxing your issues.I wish "tech2" were still here.

The man was a professional tech.

Wherever he is, I hope he returns he comes back here, but we still have really good Techs/Mechs here. Gumby22, Chem_Man, Repairman and OldChevy and many others are my equal, if not beyond, an old truck-driver who first studied in automotive technology, when I was a young man, who knew how to "turn a wrench". We are all here to help you and everyone else. It is what we do, without any thanks or response from.our advice to anyone who asks for help in a repair.

Do not give up so soon. Diagnosis of the issue is 80 to 90 percent or higher, in regards to repairing a vehicle, 24compact.