92 gmc sierra 1500 hesitation

[metalfan]

I could use some advice on this. I recently bought our 92 sierra work truck from my boss, I have a hesitation when accelerating after I have driven it for about an hour.

 

Done

-cap, rotor, plugs, wires

-Air filter

-o2 sensor

-throttle position sensor

-coolant temperature sensor

-ignition control module

-oil and filter

-fuel filter

-muffler

-catalytic converter

-cleaned egr valve

-fuel pump replaced about 12 yrs ago

 

It runs great for 30-45 minutes. Any ideas would be greatly appreciated

[2018GMC]

You can rent a fuel pressure gauge for free from autozone or orelly. Pressure should be 60 - 66 psi. KEY ON ENGINE OFF. There is no official spec for idle or throttle. Most say 55 minimum for idle and should jump past 60 when throttle blipped. Slow acceleration, hard starts, and slow or feels like engine is held back in higher rpm is a symptom of bad fuel pump.

 

I just ordered a Delphi HP10001 from rock auto for $138 shipped. Same pump is $250 at local auto part stores.

 

My 97 runs good but some hard cold weather starts.

 

I checked my fuel pressure and its 59-60 key on engine off and 52 at idle, jumps to 61 after blipping throttle.

 

I could probably run pump longer but my fuel gauge has been all over place for traders and hell maybe I will pick up a bit of performance.

[metalfan]

Thanks for the reply. That would be my next step, I was hoping to avoided the fuel pump swap, but such is life.

[2018GMC]

Ha. I'm about to do a pump on my 97. Supposedly propping the pickup bed up a few inches is the easiest way to do it. Just ask YouTube LOL. I will probably give the box method a try since pulling the tank the past 2 times sucks. Of course I just filled up!

[metalfan]

Yea, I have seen that too. I just filled mine up as well

[metalfan]

I might try lifting the bed too

[metalfan]

I just watched some videos of some guys that cut a square hole in their bed to access the fuel pump. Lol

[metalfan]

It actually looks like a good method, I may find a way to reseal it and give it a shot. It's just a work truck anyway.

[metalfan]

Went ahead and did the fuel pump. Cut an access panel in the bed. Measurements were a bit off from the youtube video, but not too bad. The hesitation seems to have been rectified.

[metalfan]

Rebuilt the Tbi unit today, all is well