Hi all. Not sure if this is the right place within this forum but here goes. I have a misbehaving 1989 GMC 2500 6.2. Stacks and body lift are the only obvious mods. Several months ago the service fuel filter idiot light pops on. I read up and learn this could cause bigger problems down the road so though I wasn't noticing any performance issues I changed the filter. The light was only coming on when load was being placed on the motor, i.e. hills or acceleration. The behavior of the light did not abate and within a day a noticeable performance issue was noted. Bogging on acceleration and over more time stalling. More bleeding no change. I replaced the lift pump (on the frame rail driver side) and the fuel line from the pump to the filter because the metal line seemed to have been crimped. The truck sat for several months this winter until today. I changed the filter again and bled the system and tightened down the bleeder screw as much as possible. Light still comes on during aggressive acceleration but I haven't experienced performance issue as yet. I understand from other sources that these box filters can be problematic. It was recommended to me that I bypass this type of filter but have no idea how to proceed. Any ideas about the problem with any fixes will be much appreciated.

Thanks
Steve

 

Hotwire the lift pump & Run about 1/2 gallon of fuel or more out the drain into a clear container. I use a gallon pickle jar. Let it sit for 20 minutes or so and look for water bubbles and crud.
I've cured problems before just by doing this.

Did you test the lift pump you took off? Did you save it? If no & yes then put a hose on each end. I use a big hose clamped over the hex parts of the lift pump and try to pump from container to container. If it has good flow save it and use it for a utility pump.

At the very least save the wire connector.

The 1993 pumps had a little higher capacity but I believe their plugs were reversed. You could use this plug in place of the plug on the truck to convert to a 1993 lift pump.

Please confirm the lift pump capacities.

I never had any problem with that filter on my 89 in 800,000 miles.

If you want to change you have several choices. The cheapest might be a 1993 or newer fuel filter manager