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Gary, Chevy Technician
Category: Chevy
Satisfied Customers: 17015
Experience:  15 years GM master tech
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Have a 2004 Tahoe I just bought. It runs like new 30

Customer Question

Have a 2004 Tahoe I just bought. It runs like new for about 30 minutes. It then starts chugging at full throttle,and eventually will get where it won't rev over 3500 and will stall and die. Weird thing is if you turn the key off and back on it will run
great again for 15-30 minutes. I hooked a pressure gauge up at the fuel rail and it's only showing 10psi with key on priming . Then as soon as I crank it (before the engine actually starts)it jumps up close to 50psi. Once engine is running it stays at about
42 psi. Is there anything this could be but a pump? Never seen a pump react this way.
Submitted: 2 years ago.
Category: Chevy
Expert:  Gary replied 2 years ago.

is the fuel filter new ?

Customer: replied 2 years ago.
No I haven't replaced anything. I couldn't figure out why it would run perfect first 30 minutes you drive it. Then when it does act up if you cycle the key it runs perfect again. Can a filter cause this? Also hardly no pressure when key on primed it has no pressure (10 psi) then as soon as I crank it jump up.
Expert:  Gary replied 2 years ago.

this can be caused by the filter plugged up and over straining the pump

if changing the fuel filter the truck still does this the only thing left to cause this fuel pressure issue is a bad fuel pump and when the old one is removed inspect the bottom of the fuel tank and be sure there is no debris in the bottom which could cause pump fuel pump delivery

Customer: replied 2 years ago.
Ok so this couldn't be a regulator? Or a relay problem. I'll go get a filter now.
Expert:  Gary replied 2 years ago.

usually a fuel pump issue itself

to see if it is a regulator you get the truck to act up then shut it off and pull the vacuum line of the regulator at the fuel rail and if you see any fuel coming out of it the regulator is bad

check that before the fuel pump is changed

Customer: replied 2 years ago.
Ok thanks. it usually acts up above 3500 rpm. Do I unplug it while reving it or with engine off?
Expert:  Gary replied 2 years ago.

with the engine off and look for fuel

Customer: replied 2 years ago.
Oreilly is telling me the fuel filter is non serviceable on this. Is this true?
Expert:  Gary replied 2 years ago.

2004 was an odd year if it has a changeable fuel filter under the drivers side frame rail

early 2004's had them and late 2004's did not

do a visual under the drivers side inner frame rail if you do not see a fuel filter on the fuel line in that area of the frame then this must be a late 2004 without a changeable fuel filter

Customer: replied 2 years ago.
Mine had the fuel filter on the frame. I replaced it now it won't even start at all. I have no clue what I could have done wrong just changing a fuel filter. It only goes on one way. Quick connect on one end.
Expert:  Gary replied 2 years ago.

is there any fuel pressure at all when key ON engine OFF ? and is the fuel pump running in the tank for the 2 second prime and when cranking it over ?

i do not think you did anything wrong at all..filter only goes on one way

Customer: replied 2 years ago.
Fuel pressure gauge is reading 0 now on the rail. Believe I can here pump come on. Defiantly not the loud buzzing you can clearly hear on most Chevys though. If it is the pump It just seems odd that it decided to go completely out after changing fuel filter
Expert:  Gary replied 2 years ago.

i agree with you

if there is NO pressure and the pump is running either the pump is bad or the fuel tank is out of fuel due to a fuel sender reading the wrong fuel level in the tank