The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 09-16-2022, 05:55 PM   #1
1972K20
Registered User
 
1972K20's Avatar
 
Join Date: Nov 2010
Location: Alabama
Posts: 739
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!
1972K20 is offline   Reply With Quote
Old 09-16-2022, 10:49 PM   #2
Dead Parrot
Registered User
 
Join Date: Aug 2012
Location: Oklahoma City, OK
Posts: 2,461
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.
Dead Parrot is offline   Reply With Quote
Old 09-17-2022, 05:30 AM   #3
GM72K10
Next!
 
GM72K10's Avatar
 
Join Date: Jan 2003
Location: Eastern Pa.
Posts: 2,477
Re: 6.2 Diesel Fuel Pump Question

What Dead Parrot said.
__________________
86 K30 CUCV M1028A1
86 K30 CUCV M1028a2 dually
86 K30 C&C 6.2 4:56s, 4M, 11,000 gvw, ex fire truck, now lowboy dump
More square bodies and CUCVs than I care to admit to
2020 Silverado K3500HD Work truck
GM72K10 is offline   Reply With Quote
Old 09-17-2022, 06:25 PM   #4
Corts60
Just here to tinker
 
Corts60's Avatar
 
Join Date: Jun 2008
Location: Holland, MI
Posts: 3,672
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.
Corts60 is offline   Reply With Quote
Old 09-17-2022, 10:06 PM   #5
1972K20
Registered User
 
1972K20's Avatar
 
Join Date: Nov 2010
Location: Alabama
Posts: 739
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.
1972K20 is offline   Reply With Quote
Old 09-19-2022, 10:04 PM   #6
karlbenz
Registered User
 
Join Date: Nov 2008
Location: kannapolis, nc
Posts: 502
Re: 6.2 Diesel Fuel Pump Question

Quote:
Originally Posted by 1972K20 View Post
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.
I thought they used an electric pump at some point. The ford idi guys were talking about them on another forum
__________________
2000 c3500 utility bed 7.4l 5sp manual old body style. Cab and chassis
1964 GMC K10
karlbenz is offline   Reply With Quote
Old 09-19-2022, 10:11 PM   #7
Willowrun
Senior Member
 
Willowrun's Avatar
 
Join Date: Mar 2013
Location: Ann Arbor, MI
Posts: 1,019
Re: 6.2 Diesel Fuel Pump Question

I have a '93 G30 van with a 6.2. Nothing electrical in its fuel pumping system.
Willowrun is offline   Reply With Quote
Old 09-20-2022, 06:47 PM   #8
hatzie
Moderator
 
hatzie's Avatar
 
Join Date: Oct 2008
Location: Wentworth, NH
Posts: 4,911
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.
__________________
1959 M35A2 LDT465-1D SOLD
1967 Dodge W200 B383, NP420/NP201 SOLD
1969 Dodge Polara 500 B383, A833 SOLD
1972 Ford F250 FE390, NP435/NP205 SOLD
1976 Chevy K20, 6.5L, NV4500/NP208 SOLD
1986 M1008 CUCV SOLD
2000 GMC C2500, TD6.5L, NV4500
2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263
2009 Impala SS LS4 V8


RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...Please include at least the year and model in your threads. It'll be easier to answer your questions.
And please let us know if and how your repairs were successful.
hatzie is offline   Reply With Quote
Old 09-27-2022, 10:22 AM   #9
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
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.
Honest Bob is offline   Reply With Quote
Old 09-27-2022, 12:28 PM   #10
hatzie
Moderator
 
hatzie's Avatar
 
Join Date: Oct 2008
Location: Wentworth, NH
Posts: 4,911
Re: 6.2 Diesel Fuel Pump Question

Quote:
Originally Posted by Honest Bob View Post
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.
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.
__________________
1959 M35A2 LDT465-1D SOLD
1967 Dodge W200 B383, NP420/NP201 SOLD
1969 Dodge Polara 500 B383, A833 SOLD
1972 Ford F250 FE390, NP435/NP205 SOLD
1976 Chevy K20, 6.5L, NV4500/NP208 SOLD
1986 M1008 CUCV SOLD
2000 GMC C2500, TD6.5L, NV4500
2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263
2009 Impala SS LS4 V8


RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...Please include at least the year and model in your threads. It'll be easier to answer your questions.
And please let us know if and how your repairs were successful.
hatzie is offline   Reply With Quote
Old 09-29-2022, 08:58 PM   #11
special-K
Special Order

 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,764
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
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed"

GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project)
GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~
special-K is offline   Reply With Quote
Old 09-30-2022, 05:28 AM   #12
Corts60
Just here to tinker
 
Corts60's Avatar
 
Join Date: Jun 2008
Location: Holland, MI
Posts: 3,672
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.
Corts60 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 09:09 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com