99 suburban fuel problem

[aeby]

i have a fuel guage flutter and whining sound inside the cab. replaced fuel pump assy with oem, no change. think i narrowed it down to the fuel pressure regulator. does the lower plenum need to be removed to access fuel rail where sensor is located? if not, does the coolant need to be drained?

[MT-2500]

What sub what engine and engine code.
A good fuel pressure test will usualy test the fuek pressure regulator.
Check the fuel pressure with a full pressure test.
Fuel pump and fuel gauge is two different things.

[aeby]

5.7L engine code R. I've read a lot of posts about an erratic fuel guage when ignition is turned on it goes way past full or empty. Can't imagine what else may be causing the fluttering issue. Thanks.

[MT-2500]

What size sub and 2W or 4W?
Is the fuel gauge only problem now?

Have you checked all grounds And wiring to tank unit.
Have you checked the dash gauge operation?
Any other thing on dash acting up.

Try some different resistors on dash gauge to check for consistent gauge operation.

[aeby]

2WD. it's running fine. no codes, no missing. will try looking at resistors on guage. 139,000 miles.

[MT-2500]

There is no restistors on but you can use restistors to check the gauge operation.

[j cAT]

Originally Posted by aeby

i have a fuel guage flutter and whining sound inside the cab. replaced fuel pump assy with oem, no change. think i narrowed it down to the fuel pressure regulator. does the lower plenum need to be removed to access fuel rail where sensor is located? if not, does the coolant need to be drained?

a rapid fuel gauge flutter is usually the dash circuit board...but I could also be a ground that is not secure....


A wondering fuel gauge needle is the fuel pump sender resistor in the fuel tank....you could attach a resistor so as to bypass the tank sender to verify it is in the fuel tank...