6.2 Diesel Fuel Pump Question
 

I have a 1988 V30 crew cab 6.2 diesel. I'm working through troubleshooting a fuel issue and I discovered that there is an electric fuel pump under the cab on the passenger side mounted to the frame rail. I noticed the wire for this pump goes along the frame rail, up to the passenger fender and is not connected to anything. There's not even a connector on the end of the wire. This truck has been starting and running without issue for over a year without this fuel pump connected. I don't know where the wire from the pump is supposed to go. Does anyone have a wiring diagram for this truck or know where the electric fuel pump is supposed to be wired? Thanks!

Re: 6.2 Diesel Fuel Pump Question
 

Don't know about 1988 but my 1986 CUCV(built to 84 specs per military request) has a mechanical fuel pump in similar place as the SBC. That feeds to the injector pump.

If yours has the mechanical pump, you shouldn't need any other pump in front of the IP.
If yours doesn't, maybe the first stage pump is an in tank pump.
In either case, possible the frame electric pump was a temp solution that was left in place just in case the original problem happened again.

Re: 6.2 Diesel Fuel Pump Question
 

What Dead Parrot said.

Re: 6.2 Diesel Fuel Pump Question
 

You should have a mechanical lift pump as mentioned above. Someone probably added the electric at one point to help with priming after a filter change.

Re: 6.2 Diesel Fuel Pump Question
 

Thanks for the replies. I think it must have been added on at some point. The odd things is, when researching GM parts for a 1988 V30, it shows a mechanical fuel pump and an electric fuel pump.

Re: 6.2 Diesel Fuel Pump Question
 

I thought they used an electric pump at some point. The ford idi guys were talking about them on another forum

Re: 6.2 Diesel Fuel Pump Question
 

I have a '93 G30 van with a 6.2. Nothing electrical in its fuel pumping system.

Re: 6.2 Diesel Fuel Pump Question
 

1993 is the last year of the mechanical injection pump and likely the same goes for the lift pump.

1993 has the DS2 mechanical throttle injection pump 6.5L and likely the mechanical lift pump.
1994 and newer definitely has an electric lift pump and the problematic DS4 electronic throttle injection pump.

Re: 6.2 Diesel Fuel Pump Question
 

The mechanical pumps are a pita to change and trying to bleed after fuel filter changes is difficult. The previous owner of my M1009 installed an electric pump (Mr Gasket type) which eventually died but I replaced it with a 95ish chevy diesel electric pump.

Re: 6.2 Diesel Fuel Pump Question
 

They had Stanadyne 80 box filters. Darn poor excuses for a fuel filter, the base leaks like a sieve, and straight up pain in the posterior to bleed no matter what you use for a lift pump.

You can install the Stanadyne Fuel Manager 100 in the intake valley just like the late 1990's trucks. You can actually bleed that unit fairly easily on the cam driven mechanical pump.

Re: 6.2 Diesel Fuel Pump Question
 

It sounds like a lift pump in your fuel line. I know the first 6.5TDs in used then to assist the mechanical pump, ease it's load. I've had a few 6.2 trucks and can't remember if they used an electric lift pump. The power should come from the oil pressure switch. Pump cuts out when oil pressure drops for safety in accidents.

What kind of fuel issue are you having? Starting problems? If you still have the factory fuel filter on the firewall it could be the culprit. The base will crack and suck in air. I had that problem. Kept having to bleed air out over and over. No replacement for this inferior part available. I went with a 6.5 cartridge type filter that mounts on the back of the engine up top

Re: 6.2 Diesel Fuel Pump Question
 

Buy a Racor 500 series filter assembly, mount it to the firewall and be done with that factory garbage filter. You’ll never have problems again with filter pulling in air. And the racor elements are like $15.