2001 Tahoe 5.3L - Stall while driving, starts but doesn't build pressure to run.

[Charles Kazemi]

Hey all,

I've been reading everything I can to see whats wrong with my Tahoe. I feel that it all leads back to a faulty fuel pump but some of my symptoms, I feel, do not match exactly what happened to me tonight. Maybe I over looked something, so I'm throwing it out there for feedback and thoughts if you have a second. Appreciate your time in advance!

I have roughly 146K miles on this Tahoe, runs like a dream, runs strong! Tonight I started her up, threw her in drive and maybe 50 feet later I got the put-put feeling associated with what I thought was out of gas, then she stalled out. I immediately thought I was out of gas and maybe my gauge was wrong as my last car had a similar issue if I ignored the low reading for too long.

I put 2 gallons in, started the car right up. I drove a few feet before stalling out once again. I assumed I needed more gas for a larger and older vehicle so I put another 2 gallons in. I noticed then the gauge went from 1/2 to 3/4 tank so that dismissed my "out of fuel so you fried the fuel pump" theory. Car starts effortlessly, but when pedal pressure is applied it inevitably stalls out. If I let her idle for too long, roughly 30 seconds, the rough idle will stalls out as well.

I read all the forums; listen for fuel pump hum, pump relay switch faulty, faulty fuel pump, clogged line, air in lines, turn "on" but dont start for 10 minutes, turn "on" then off 5 times to get air out, catalytic converter this, ignition switch filthy that, etc... but ultimately still not sure. The reason as to why I'm asking, does a weak/failing fuel pump allow the car enough gas to start but not run? I never found an answer to that question. Maybe its something different entirely?

Appreciate the love, thank you!
Charles

We like to be "DUG".

Just an update; pressure test came back 20 PSI. Headed to Napa Auto l for a new fuel pump. Thanks all!!

 

[Rocket Man]

Just enough to run at an idle. Let us see what the top of your fuel tank looks like, sometimes they’re pretty rusty around the pump.

 

[OR VietVet]

Make sure you do the filter and relay as well but is your call. Plus, like Rocket Man said, pics of the tank top and be aware of the evap lines there.

 

[Charles Kazemi]

Just enough to run at an idle. Let us see what the top of your fuel tank looks like, sometimes they’re pretty rusty around the pump.

Done deal, I'll post this weekend when I get around to putting it together. Thank you!

 

[Charles Kazemi]

Make sure you do the filter and relay as well but is your call. Plus, like Rocket Man said, pics of the tank top and be aware of the evap lines there.

I'm going to replace the filter first, see if that works! The relay worked when I was able to bleed the lines and run the pressure test, right? But thanks for the input and advice.
Chuck

 

[OR VietVet]

That filter would have to be more clogged than I have ever seen to keep the truck from running. Plus, the pump is immersed in the fuel to keep it cool, so when you drive, always consider at least a 1/4 tank as empty. Bad to run fuel down too low and damage the pump. I don't like to get below half tank.

 

[iamdub]

I'd imagine a clogged filter to worsen over time, making your symptoms worsen over time. It'd start out with reduced power when passing or climbing hills, then reduced power when cruising and eventually get to the point it's at now.

Also, the pump should be in a bucket in the pump module. It has a venturi feed setup that keeps the bucket full and the pump immersed regardless of the fuel level of the tank.

 

[Charles Kazemi]

That filter would have to be more clogged than I have ever seen to keep the truck from running. Plus, the pump is immersed in the fuel to keep it cool, so when you drive, always consider at least a 1/4 tank as empty. Bad to run fuel down too low and damage the pump. I don't like to get below half tank.

Thats a great way to be, thanks for the thought!
Chuck

 

[Charles Kazemi]

Update: I replaced the fuel filter on Saturday morning before replacing the fuel pump. I didnt have a pressure gauge but it reved, idled and drove so much better but still rough (not full power).

I just finished installing a new fuel pump, the truck runs and revs but stalls and low idles when in drive. I've got to get another pressure gauge to see where we are at but any idea as to why the sudden lack of power when replacing both pump and filter?

Any thoughts on sea foam?

 

[iamdub]

Gotta verify fuel pressure first. Faulty new pumps are far from unheard of. Your best chances at getting a good one is to use an ACDelco or Delphi pump. GM vehicles seem to eat up aftermarket brand pumps. Did the new pump have the updated bulkhead harness connector?

Is your SES light on?