Author Topic: Quality OE Fuel pumps?  (Read 4237 times)

Offline Scaryfastatx

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Quality OE Fuel pumps?
« on: September 30, 2026, 10:21:05 pm »
Anybody have any guidance?

On my 305 dualjet with return, I had a carter pump and it lasted about 1-2 years

Finally gave out a few weeks ago

I ordered a Delphi and it was dead out of the box, wouldn't hold pressure unless I capped off the return line

Got a replacement Delphi shipped by the vendor

The replacement worked for about 30 minutes and then died, luckily I had some vice grips and was able to make it home.

The replacement won't hold pressure unless the return is capped also

It's crazy that you can't find a good fuel pump anymore

Offline Mr Diesel

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  • Aaron
Re: Quality OE Fuel pumps?
« Reply #1 on: October 01, 2026, 08:24:19 pm »
Are you talking electric or mechanical pump?
1976 C20 Crewcab, 6.2L/SM465
1982 K30 Crewcab , 427TD/TH400
1983 C30, 6.2L/TH400
1983 K30 Crewcab 454/700R4
1986 K10 350/400. 1989 K30 cab/chassis 454/SM465

Offline JohnnyPopper

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  • Old Goof
Re: Quality OE Fuel pumps?
« Reply #2 on: October 06, 2026, 08:36:36 pm »
sounds like mechanical.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Scaryfastatx

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Re: Quality OE Fuel pumps?
« Reply #3 on: October 09, 2026, 09:53:19 am »
Yeah, it's mechanical

So 3 Delphi, none of them had an orifice on the return bung, one of them worked for 30-45 minutes before it lost enough pumping capacity due to the full flow return

I didn't notice it didn't have the orifice was missing until I pulled it off

Also noticed the dreaded A stamped on the, so I guess Delphi white labels through Airtex


Pump #2


Pump #3




I ordered a Carter again, has the orifice and truck is back on the road, I'll take 3 years operation Vs 30 minutes any day

Offline Mr Diesel

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  • Aaron
Re: Quality OE Fuel pumps?
« Reply #4 on: October 09, 2026, 03:09:08 pm »
Garbage aftermarket. I could keep my old junk running forever if there was just some decent replacement repair parts.

I avoid anything stamped in China. Best option is usually Taiwan, followed probably by Mexico, U.S., and any other country besides China.
1976 C20 Crewcab, 6.2L/SM465
1982 K30 Crewcab , 427TD/TH400
1983 C30, 6.2L/TH400
1983 K30 Crewcab 454/700R4
1986 K10 350/400. 1989 K30 cab/chassis 454/SM465

Offline Scaryfastatx

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  • Posts: 88
Re: Quality OE Fuel pumps?
« Reply #5 on: October 14, 2026, 06:16:44 pm »
WELP!

the latest carter M6266 just died after 3 days
2 trips to work, and half a trip to the grocery store...


I've been testing the Delphi ones, and one of them with the return port plugged seems like it might work

Thinking about putting an in line orifice or maybe scavenging the orifice off of the M6266

Also thought maybe turning down some 0.060" jets and shoving them into the return hose


Offline Mr Diesel

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  • Aaron
Re: Quality OE Fuel pumps?
« Reply #6 on: October 14, 2026, 09:30:04 pm »
Can you open them up and find the points of failure? Multiple pumps doing this points to a likely problem elsewhere, unless you can pinpoint the reason for failure.

Last one that failed on me was a plastic pivot piece inside. China part. Replaced it with a Carter that was metal components instead. A carburetor requires very little pump pressure so your failure inside the pump should be pretty obvious.
1976 C20 Crewcab, 6.2L/SM465
1982 K30 Crewcab , 427TD/TH400
1983 C30, 6.2L/TH400
1983 K30 Crewcab 454/700R4
1986 K10 350/400. 1989 K30 cab/chassis 454/SM465