Need advice on 94 3500 :)

[Mr. Bob]

Hello all,

My buddy has a 1994 K3500 6.5L. He phoned me today with some problems... He said it is running poorly on the highway, like a missfire, and I believe he said it is stalling aswell. Assuming he is up to date on air and fuel filters ( which he may not be ) is there anything I should be looking at first??? I am really not that familiar with the 6.5Ls.....

Thanks so much!!!
Bob

 

[chrisk1500]

lift pump and fuel filters would be my first checks...

 

[Dave Barbieri]

If you've got an air leak in your supply line, it'll cause stalling and crummy performance. You can crawl under the truck and inspect the line inch by inch, buth there's an easier way to see if this is even the problem:

Check for air in the return fuel line. This is the 1/4" line that comes off the top of the injection pump and hooks into the metal line that runs in front of the pump. Use Tygon fuel line - it's available at most mower shops that repair chainsaws and weedeaters. It's yellow or green, and available in different diameters. Great stuff - it'll tolerate fuels and harsh chemicals, and it's clear. I replaced the return lines on my diesel veedubs and my Ford 6.9 with the stuff; it makes it real easy to see if any air is finding its way into the system. And when you open the hood and see a bunch of bright green/yellow fuel lines, it makes you smile.

If you've got big bubbles showing up in the return line, it's time to start checking the supply side of the food chain.

 

[towcat]

1994 truck should have a electric fuel pump.
change the fuel filter first. the described symptoms are fuel filter related.

 

[JLDickmon]

yeah, check those, to make sure it's not something stOopId before you have him spend the jingle on the injector controller...

you might want to contact GM as well, I've seen a TSB on those that accounts as one of those "super secret squirrel" recalls on the injector pump

 

[Dave Barbieri]

you might want to contact GM as well, I've seen a TSB on those that accounts as one of those "super secret squirrel" recalls on the injector pump

You're referring to 'Special Policy 00064, 9/2000; Special Policy Adjustment - Electronic Diesel Fuel Injection Pump Failure - Repair or Replace'. This special policy covers "vehicles manufactured between 1994 and 1998". The coverage limits are 11 years or 120,000 miles, whichever occurs first. Because of the time liits, this SP now only applies to model years 97 and 98 with fewer than 120k,