Fuel issues

[scrambled]

I have been tinkering with one of my 1008s and It fires right up, runs a sec or two then dies. It then cranks over for 20 seconds or so to fire back up.

I figure there must be a leak in the lines and the fuel is draining back. The fuel filter is completely full before I try to fire it up though. I would assume the filter had emptied out if it was leaking.

Would it stay filled? If so, this would mean a leak somwhere between the tank and the lift pump.


Thanks for any input,
Travis

 

[Dave Kay]

You can find all kinds of answers to your problems here:

Cucv Wiki - Steel Soldiers::Military Vehicles Supersite

 

[Blue2actual]

sounds like your IP is letting air in. It's burning what fuel is in there, then pushing air into the chamber until after cranking for a while as you said, it finally "flushes" all the air out and gets the diesel to combust. SOUNDS like it might be time for your IP to be rebuilt...you can try replacing the orings but you might as well get it rebuilt, especially if it is original. My 1009 is doing the same thing...I just havent gotten around to doing it

 

[jdemaris]

I have been tinkering with one of my 1008s and It fires right up, runs a sec or two then dies. It then cranks over for 20 seconds or so to fire back up.

I figure there must be a leak in the lines and the fuel is draining back. The fuel

It was a common problem with 80s trucks with 6.2s. Fuel drains back a bit towards the tank. Filters stay full, but you wind up with some air in the line. Truck starts fine, then quits. Once running awhile, it is fine until next it's parked for awhile.

I aleardy posted the GM service bulletins several times. Calls for a new fuel pump and a new regulator-valve that screws into the top of the injection pump. In regard to the fuel pump, probably any replacement pump made since 1990 has the upgraded parts.

Chevrolet bulletin # 89-329-6
Subject: 6.2L Diesel Hard starting cold
Issue date: 9-20-91
All trucks with 6.2 diesel 1982-1989 except 88/89 CK trucks with electric fuel pumps.
Even if the glow system is working properly, some 1982-89 General Motors trucks
equipped with 6.2L diesel engines may still experience cold, hard starts. GM says air leaks
in either the suction or return side of the fuel system are the source of the problem. After
the engine is shut down, air leaks can result in loss of injector pump fuel prime.
If the air leaks are on the suction side of the fuel system, GM recommends installing a new
mechanical fuel pump GM P/N 25116503 and AC Delco P/N 43254. The new pump features a new ventless check valve to prevent drainback.
If the air leaks are on the return side, a new HPCA (Housing Pressure Cold Advance)
regulator valve (P/N 10149645) must be installed. This new valve and seal configuration
superceded the old ball check regulator valve....
　

 

[Hoolio]

Happened to my M-1028.. Changed the fuel pump..No change.. Took off the fuel filter housing and looked at the back ...Slight wetness there.. Changed it out for a spin on filter and housing.. NAPA 3132 filter and aluminum spin-on base...Has worked excellent since.. I did drill and tap a plug hole right in the top of the housing on the "out port" of the filter housing.. This is so I can fill the housing with a squirt can for easier first starting..

 

[Blue2actual]

Happened to my M-1028.. Changed the fuel pump..No change.. Took off the fuel filter housing and looked at the back ...Slight wetness there.. Changed it out for a spin on filter and housing.. NAPA 3132 filter and aluminum spin-on base...Has worked excellent since.. I did drill and tap a plug hole right in the top of the housing on the "out port" of the filter housing.. This is so I can fill the housing with a squirt can for easier first starting..

Hoolio,

What would you call "slight" wetness? I have a similar issue...I'm hoping it's not my IP and that it is my stock box style filter. As you can see in my picture, I have wetness on the hoses leading out of the filter box. I want to do the spin on mod, I just need to get out there and do it. But NASCAR is on.... might not happen today