3 months ago i bought a 97 GMC 2500 6.5 4x4 with 216.000 on it and have been working on the little bugs from the past 2 owners and the truck has run good until now. i changed the 4l80e trans after first buying it with another used one. i have made my own turbo master because vac pump was dead. i have 3inch down pipe into 4 inch then in to 5inch stacks. the past few weeks when taking off the truck surges like its not getting fuel or somthing. looking to maybe replace OPS and i have ordered a new lift pump. mine is lowed when the wait to start and then it makes almost no noise once started. not sure what to do. it doesnt do it all the time and sometimes only in the first 5 min of running and then sometimes after sitting stoped at a drive threw.

sorry this is long.

 

Have you checked the voltage at the harness plug for the LP? Plugged in and unplugged?

New OPS is only about $40-$50 dollars for an AC Delco brand.

 

what should the voltage be? i think part of my problem might have been my fuel filter not seated right? but it wasnt leaking fuel. could it suck air but not leak fuel?

 

If the lift pump is working, it would leak fuel. If the lift pump is not working, it would suck air.

 

i changed my pmd seated the fuel filter again and bled the system and i havent had any more problems. its running better then ever and has power

 

how would sand size dirt get into the bottom of my fuel filter bowl ? cleaned it out and then dumped seafoam in to fill the bowl back up

 

if it's in the settling bowl, it's coming from the tank. Pick a time period and re-examine the bowl to see if you have a load of fresh sand, or if, perhaps, that sand has been there for years and years, or not. Lots of ways for sand to get into a fuel system--- previous owner might have had an unsanitary road-side refueling, pissed-off ex-wife with a Dixie cup, stealing fuel from a bulldozer, etc, etc, etc

 

it has a new tank so i think i was the 1st owner. its been running great now !