6.2 fuel sending unit problems - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Adam j · 03-12-2018, 08:48 PM

I'm changing the sending unit on my 6.2 and can't find one like it it has 3 outlets and one plug for the gauge and a exterior ground and two of the outlets go into the tank are long and one is short I can't find another like it anywhere it is a old military truck so who knows what it's from and when I look at the one it recommends it has two plugs and the ground is internal please help thanks
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andyh1956 · 03-12-2018, 10:16 PM

Try a Spectra FG05K for driver side or FG05L for pass side.
For surplus try Hillbilly Wizard or Ted's Trucks & Stuff.
These are for M1008 but may be the same for M1009.

Adam j · 03-13-2018, 01:36 PM

Quote:

Originally Posted by andyh1956

Try a Spectra FG05K for driver side or FG05L for pass side.
For surplus try Hillbilly Wizard or Ted's Trucks & Stuff.
These are for M1008 but may be the same for M1009.

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Adam j · 03-13-2018, 01:37 PM

Quote:

Originally Posted by Adam j

Posted via Mobile Device

Those parts don't match the one I have I tried them thanks for the help
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andyh1956 · 03-13-2018, 03:19 PM

When you say two plugs that's electrical plugs correct?
Will your wiring harness plug into one of the plugs or do the wires need to be "Divided" between the plugs?
You have an M1008 or M1009 or is your tank just from a CUCV?

sweetk30 · 03-13-2018, 05:35 PM

post up some pics of what ya got . see if I can match it.

I have 2 tanks with senders from a diesel truck I parted .

looked up for 1985 k30 6.2 diesel . verified 1984 - 1985 - 1986 the vintage of almost all military trucks of this style take the same sender listed . unless military did a weird custom thing .

driver side 3 port https://www.rockauto.com/en/moreinfo...053065&jsn=459

pass side 3 port https://www.rockauto.com/en/moreinfo...053065&jsn=458

these what you looking for ?

1 plug/pin is sender feed . the other is water in fuel ? if I recall.

short is tank vent / 5/16 is return line / 3/8 is fuel supply . ground is flat spade on 1 of the lock tabs in the pic .

**hatzie** · 03-17-2018, 09:43 PM

How old is the fuel filter?

Adam j · 03-18-2018, 12:03 AM

My dad had been using this truck as his everyday driver for a year and it has new fuel in it now we replaced the tank and sending unit and fuel filter and nothing has changed plus the fuel pump is new
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**hatzie** · 03-18-2018, 11:38 AM

Is it surging when the power drops off?

Adam j · 03-18-2018, 12:34 PM

No it's just dies no jumping or nothing like that
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Adam j · 03-18-2018, 04:51 PM

Anyone have any ideas it's still losing power and it seems to be worse when it's hot
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wildwilly4x4 · 03-19-2018, 12:32 AM

check fuel return lines. blow through from injection pump outlet with air back to tank. also check to see if the fuel return fitting in the top of the injection pump is clogging up. there's a glass check ball inside that fitting that can trap junk in there

wildwilly4x4 · 03-19-2018, 12:34 AM

back pressure on the fuel return is actually what kills a 6.2 truck when you shut them off. seen the return hose and that outlet fitting plugged more than once in my fleet of trucks.

andyh1956 · 04-13-2018, 10:35 AM

I found this in my CUCV manuals.
GM part # for Fuel, Tank Meter on M1008 is 25004137.
For the M1009 it is 25004140.
The units are different between the M1008 & M1009

**hatzie** · 04-13-2018, 09:55 PM

The M1009 is a Blazer chassis with the tank between the frame rails.
M1008 M1010 M1028 & M1030, I think I got em all, are pickups with saddle tanks.

andyh1956 · 04-15-2018, 10:48 AM

By looking at the illustrations, the M1009s have four outlets & M1008s have three. The center outlet on the M1008 hooks to a short piece of tubing that drops over to inside the frame & has a cap on it. They list this assy as a "Tank Drain".
I spose you are to hook a pump onto this & suck the tank out.
I'll look in my TMs for the procedure.
But in the short run it looks like a feature not needed for our purposes.

**hatzie** · 04-15-2018, 02:25 PM

You really only need vent, supply, and return for the diesels. The tank drain is superfluous.

GM stopped installing the tank drain in the Civvy rigs around 1984 or 1985 or so. Since the military spec for the trucks was based on an early 1984 chassis, and the military gets nervous about changes, they kept building them exactly the same til Uncle Sam stopped ordering them.

If it's stock pre mid-84 you'll find a valve somewhere around the spring hanger on the frame. It may actually be inside the spring hanger. The TM will probably tell you. You can get rid of this drain line unless you're going for exactly original.

andyh1956 · 04-15-2018, 03:07 PM

Quote:

Originally Posted by hatzie

You really only need vent, supply, and return for the diesels. The tank drain is superfluous.

GM stopped installing the tank drain in the Civvy rigs around 1984 or 1985 or so. Since the military spec for the trucks was based on an early 1984 chassis, and the military gets nervous about changes, they kept building them exactly the same til Uncle Sam stopped ordering them.

If it's stock pre mid-84 you'll find a valve somewhere around the spring hanger on the frame. It may actually be inside the spring hanger. The TM will probably tell you. You can get rid of this drain line unless you're going for exactly original.

"SuperWho"???

**hatzie** · 04-15-2018, 04:22 PM

superfluous
[soo-pur-floo-uh s]

adjective

1. being more than is sufficient or required; excessive.
2. unnecessary or needless.
3. Obsolete. possessing or spending more than enough or necessary; extravagant.

Ahh tends ta use them thar big words sometaahms.

andyh1956 · 04-16-2018, 12:00 AM

This forum is FULL of $10 words today!

03-12-2018, 08:48 PM	#1
Adam j Registered User Join Date: Apr 2012 Location: Lexington south Carolina Posts: 98	6.2 fuel sending unit problems I'm changing the sending unit on my 6.2 and can't find one like it it has 3 outlets and one plug for the gauge and a exterior ground and two of the outlets go into the tank are long and one is short I can't find another like it anywhere it is a old military truck so who knows what it's from and when I look at the one it recommends it has two plugs and the ground is internal please help thanks Posted via Mobile Device

03-12-2018, 10:16 PM	#2
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: 6.2 fuel sending unit problems Try a Spectra FG05K for driver side or FG05L for pass side. For surplus try Hillbilly Wizard or Ted's Trucks & Stuff. These are for M1008 but may be the same for M1009.

03-13-2018, 03:19 PM	#5
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: 6.2 fuel sending unit problems When you say two plugs that's electrical plugs correct? Will your wiring harness plug into one of the plugs or do the wires need to be "Divided" between the plugs? You have an M1008 or M1009 or is your tank just from a CUCV?

03-13-2018, 05:35 PM	#6
sweetk30 Registered User Join Date: May 2012 Location: horseheads,ny rust belt Posts: 2,794	Re: 6.2 fuel sending unit problems post up some pics of what ya got . see if I can match it. I have 2 tanks with senders from a diesel truck I parted . looked up for 1985 k30 6.2 diesel . verified 1984 - 1985 - 1986 the vintage of almost all military trucks of this style take the same sender listed . unless military did a weird custom thing . driver side 3 port https://www.rockauto.com/en/moreinfo...053065&jsn=459 pass side 3 port https://www.rockauto.com/en/moreinfo...053065&jsn=458 these what you looking for ? 1 plug/pin is sender feed . the other is water in fuel ? if I recall. short is tank vent / 5/16 is return line / 3/8 is fuel supply . ground is flat spade on 1 of the lock tabs in the pic . __________________ 77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great. Last edited by sweetk30; 03-13-2018 at 05:48 PM.

03-17-2018, 09:43 PM	#7
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: 6.2 fuel sending unit problems How old is the fuel filter? __________________ 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... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF 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.

03-18-2018, 12:03 AM	#8
Adam j Registered User Join Date: Apr 2012 Location: Lexington south Carolina Posts: 98	My dad had been using this truck as his everyday driver for a year and it has new fuel in it now we replaced the tank and sending unit and fuel filter and nothing has changed plus the fuel pump is new Posted via Mobile Device

03-18-2018, 11:38 AM	#9
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: 6.2 fuel sending unit problems Is it surging when the power drops off? __________________ 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... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF 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.

03-18-2018, 12:34 PM	#10
Adam j Registered User Join Date: Apr 2012 Location: Lexington south Carolina Posts: 98	No it's just dies no jumping or nothing like that Posted via Mobile Device

03-18-2018, 04:51 PM	#11
Adam j Registered User Join Date: Apr 2012 Location: Lexington south Carolina Posts: 98	Anyone have any ideas it's still losing power and it seems to be worse when it's hot Posted via Mobile Device

03-19-2018, 12:32 AM	#12
wildwilly4x4 Registered User Join Date: Aug 2009 Location: Sunray,TX Posts: 251	Re: 6.2 fuel sending unit problems check fuel return lines. blow through from injection pump outlet with air back to tank. also check to see if the fuel return fitting in the top of the injection pump is clogging up. there's a glass check ball inside that fitting that can trap junk in there

03-19-2018, 12:34 AM	#13
wildwilly4x4 Registered User Join Date: Aug 2009 Location: Sunray,TX Posts: 251	Re: 6.2 fuel sending unit problems back pressure on the fuel return is actually what kills a 6.2 truck when you shut them off. seen the return hose and that outlet fitting plugged more than once in my fleet of trucks.

04-13-2018, 10:35 AM	#14
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: 6.2 fuel sending unit problems I found this in my CUCV manuals. GM part # for Fuel, Tank Meter on M1008 is 25004137. For the M1009 it is 25004140. The units are different between the M1008 & M1009

04-13-2018, 09:55 PM	#15
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: 6.2 fuel sending unit problems The M1009 is a Blazer chassis with the tank between the frame rails. M1008 M1010 M1028 & M1030, I think I got em all, are pickups with saddle tanks. __________________ 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... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF 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.

04-15-2018, 10:48 AM	#16
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: 6.2 fuel sending unit problems By looking at the illustrations, the M1009s have four outlets & M1008s have three. The center outlet on the M1008 hooks to a short piece of tubing that drops over to inside the frame & has a cap on it. They list this assy as a "Tank Drain". I spose you are to hook a pump onto this & suck the tank out. I'll look in my TMs for the procedure. But in the short run it looks like a feature not needed for our purposes.

04-15-2018, 02:25 PM	#17
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: 6.2 fuel sending unit problems You really only need vent, supply, and return for the diesels. The tank drain is superfluous. GM stopped installing the tank drain in the Civvy rigs around 1984 or 1985 or so. Since the military spec for the trucks was based on an early 1984 chassis, and the military gets nervous about changes, they kept building them exactly the same til Uncle Sam stopped ordering them. If it's stock pre mid-84 you'll find a valve somewhere around the spring hanger on the frame. It may actually be inside the spring hanger. The TM will probably tell you. You can get rid of this drain line unless you're going for exactly original. __________________ 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... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF 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. Last edited by hatzie; 04-15-2018 at 02:33 PM.



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04-15-2018, 04:22 PM	#19
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: 6.2 fuel sending unit problems superfluous [soo-pur-floo-uh s] adjective 1. being more than is sufficient or required; excessive. 2. unnecessary or needless. 3. Obsolete. possessing or spending more than enough or necessary; extravagant. Ahh tends ta use them thar big words sometaahms. __________________ 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... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF 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.

04-16-2018, 12:00 AM	#20
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: 6.2 fuel sending unit problems This forum is FULL of $10 words today!

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