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fuel pump or regulator causing this?

Mattt

By Mattt
in Ask A GM Technician

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Mattt Enthusiast

Mattt

Posted
Posted

2001 Suburban w/ 5.3....I replaced the fuel pump a few months back, just the pump not the complete module. I bought the pump in an ACDelco box off Ebay and the part # comes up as a ACDelco-Mexico part # BGV00250

 

Recently the Sub has been hard starting after sitting for a while. I put a pressure gauge on the schraeder valve and my fuel pressure is low....like 40 psi. At least once on a cold crank, key on, engine off it only primed(~2 sec) to 30 psi. It always starts but generally not without a long crank or cycling the key on-off-on-off-on which is giving me a longer prime.

 

 

I didn't replace the regulator when the new fuel pump went in. I'm trying to avoid just throwing parts at this problem and looking for a little help which way to go.

 

I have little faith in the Ebay pump now but I'm not sure that is the problem. The problem could just as easily be the regulator. Is there a way to discern what is causing the low pressure....regulator or pump?

 

 

Thank you in advance.

txab Senior Enthusiast

txab

Posted
Posted (edited)

Pull the vacuum line at the FPR, if you have fuel there, replace the regulator. You may also have a fuel check valve bad

 

Checked your fuel filter?

Edited by txab
angryrussian Enthusiast

angryrussian

Posted
Posted

I had a similar issue with my 02 Silverado 1500 5.3. The truck wouldn't turn over the first time I cranked it. I'd have to turn the key allowing the fuel pump to operate, then turn it back off, then on again like you're doing. It eventually got worse and worse. I replaced the FPR with no change in the problem. I then had my fuel pump and fuel filter replaced. The problem improved by having this done, but was never completely solved. Up until I got rid of it, I would start it like a diesel. Turn the key to on, pause, then crank it. If I turned the key too quickly it would be a hard start. Or if I turned the key to on and left it there for too long, I'd have to turn it back off before cranking it or the truck wouldn't start.

 

I also eventually had a section of fuel line replaced secondary to corrosion. That didn't improve the problem either.

 

Sorry I'm not much help, but I wanted to let you know you aren't alone. It always drove me nuts too because I never figured out the problem. I solved it by buying a new truck. Time will tell if that was a good fix!

Mattt Enthusiast

Mattt

Posted
  • Author
Posted

Pull the vacuum line at the FPR, if you have fuel there, replace the regulator. You may also have a fuel check valve bad

 

Checked your fuel filter?

 

 

I'll check the FPR tomorrow. Thanks for that easy check. Fuel check valve....where is it located? Fuel filter was new when the pump went in about 6 months ago. I know it could be plugged already....only way to check that is replace it. Might be an easy....what if.....

 

Thanks again for the suggestions.

WESTTC Enthusiast

WESTTC

Posted
Posted

I just had a similar problem. Replaced fuel filter, plugs and wires, with no change. Per the dealer, the check valve was bad, which made sense with what I was seeing in fuel pressure readings: initial key on gave zero pressure or full (~ 50 psi) pressure but quickly dropping afterwards. FPR was still good. Replaced fuel pump module (which I assume includes valve) and truck starts fine.

 

I agree on FPR check - pull the vacuum hose and look for fuel.

 

txab Senior Enthusiast

txab

Posted
Posted (edited)
On 3/16/2012 at 12:26 AM, Mattt said:
On 3/15/2012 at 9:47 PM, txab said:
Pull the vacuum line at the FPR, if you have fuel there, replace the regulator. You may also have a fuel check valve bad Checked your fuel filter?
Quote

I'll check the FPR tomorrow. Thanks for that easy check. Fuel check valve....where is it located? Fuel filter was new when the pump went in about 6 months ago. I know it could be plugged already....only way to check that is replace it. Might be an easy....what if..... Thanks again for the suggestions.

 

Check valve is part of the fuel pump assembly in the tank. That's why it's best to replace the complete unit when you have a pump problem

Edited by txab
  • 2 years later...
dukbludvl Enthusiast

dukbludvl

Posted
Posted

Is it possible that my fuel pressure regulator is bad even though i'm not seeing any gas when i pull the vacuum line there? My 2000 yukon with 330k miles recently started having a long crank issue. It sometimes takes 1-2 seconds, sometimes longer before it starts. Previously, it has always started really quickly (much faster compared to my wife's 2007 accord, which I always think cranks a long time when I start it by comparison to my yukon). I recently changed plugs, wires, engine air filter, fuel filter and cleaned throttle body and MAF sensor. None of that has helped. I'm on the second fuel pump (it now has about 120k miles on it in about 4 years), so maybe it's the pump going again? But, I'm wondering if it might be the fuel pressure regulator, even though I'm not seeing gas in the line. I'd rather replace the FPR for $80 than the fuel pump for $600. What do you guys think - could it be the FPR? It idles, accelerates and runs like normal once started.

  • 6 months later...
Keats Enthusiast

Keats

Posted
Posted

This is a more closley related string so I'm reposting here.

 

19 Aug 15,

2000 Chevy Silverado Ext. Cab1500, 5.3ltr, automatic trans, 2 wheel drive, with 85000 miles on it.

 

I have a similar problem. A few years ago I replaced the fuel pressure regulator on the fuel injector rail and the problem went away. It started up again a couple weeks ago and the symptoms were exactly the same as last time. I live in Arizona and I don't drive this vehicle very much,- I'm retired - and it's possible that the diaphram in the regulator dried out and was causing the problem.

 

So I replaced it with a brand new regulator ($45.00) and it started up a bit better than before I replaced the regulator.

 

I drove it today and had a hard time starting the engine. I know that the fuel pump is working because I can hear it working for a couple of seconds after I first turn the key to "On".

 

I got the engine to start and had to "Goose" it just a bit to get it to smooth out. As I drove it, I noticed that the engine hesitated a little from a stop and even when driving at a slow speed. If I was doing about 30 mph and accelerated, it sped up just fine. No hesitation that I could notice.

I parked the truck and returned about an hour later and had a hard time starting the engine again. I had the same hesitation situation while driving home. When I got it back in the garage, I turned the engine off and tried to restart it. It fired up in a heartbeat. I tried it a couple more times and got the same good results.

 

One other odd thing: My fuel gauge began fluctuating just a little when this all began. It bounces between 1/2 and 3/4 tank while the truck is just sitting still. So it's not the fuel sloshing around inside the tank.

I don't have any other draws on the electrical system such as directionals or 4 way hazard lights flashing that might cause the electric to fluctuate.

 

I'm going to hook up my OBD II to see if there are any trouble codes but in the mean time, has anyone had a similar problem?

How did you fix it?

 

Thanks,

Keats, Arizona :help:

  • 5 years later...
bill cole New Member

bill cole

Posted
Posted

Sticky starter or extended crank. Can this be fuel regulator bad when after Tahoe has been driving a lil to warm up then turn off for 20min then when you turn key to start it the starter will stay engaged for a second on its own. A couple more attempts then starts. Plz help

bill cole New Member

bill cole

Posted
Posted

Starter staying engaged for second when you try to warm start. What makes that starter stay engaged? Kinda like it lost its fuel prime. It only does this on warm start. Cold starts in morning starts right up. 

  • 4 weeks later...
Kent Short New Member

Kent Short

Posted
Posted

I have 2001 g m c Sierra 4.8 going down the road the motor surges what would cause this got new plugs new coils new wires and code comes up has a misfire

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