Fuel Pump amperage draw on 04 z71 tahoe

[Steve S]

Hi all. I have a 04 Z71 5.3 4wd Tahoe. I've started to get intermittent problems with rough engine after driving for a while highway towing.(1-2 hours) (bad or no acceleration, rough idle, wont start after dying). If I turn off engine and wait 10 minutes, the problem is gone. My mechanic can't recreate the problem when he kept it for a couple days. After looking around on the interweb, I did a test on current draw by the fuel pump. Put a multitester in place of the 20amp pcmb fuse next to the fuel pump relay in the fuse box under the hood. Got a reading of 9.85 amps. I can't seem to find a definitive number on what that draw should be. Any insight? TIA.

 

[iamdub]

I'm wondering if you have a clogged tank vent. Next time it start acting up, leave it running and unscrew the fuel filler cap, then tighten it back and continue driving to see if the problem goes away.

I don't know what the normal amperage draw should be. But, you can hook up a fuel pressure gauge to the test port and see if and how the numbers correspond to the symptoms.

 

[rockola1971]

Do you have to crank vehicle 2 or more times to get it to start after it has sat overnight or does it fire right up on first crank?

 

[Steve S]

fires right up in the morning

 

[rockola1971]

Id worry more about the fuel pressure than the fuel pump current draw (unless it was popping fuses). Is it lighting up the check engine light? If so, what are the codes? Changed the fuel filter ever?

 

[Steve S]

Fuel filter changed

 

[SnowDrifter]

Sounds like what happened to me when my fuel pump went out. Did all the diag myself, took it to a shop to let them fuss with doing it, they wanted to do their own. Couldn't replicate the issue so I just said trust me and do it. Been running fine since

Hook up a gauge, go from there. Remind me; does '04 have a returnless fuel system?