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Mechanical fuel pump replacement suggestions

Tony Mele

Jr. Member
Joined
Apr 3, 2016
Messages
132
Well it seems that my mechanical fuel pump is failing. I've got a clear filter just before the carb and it's barely getting any fuel in it at all. Engine is starving for fuel especially at highway speeds. The filter gets little dribbles of fuel.

Do I go with an off-the-shelf stock 302 fuel pump? Or does anybody on here have a different recommendation?

Thanks
 

spap

Contributor
Bronco Guru
Joined
Jan 2, 2010
Messages
2,457
There are a couple of ways you can go but why not just go the original mech. Fuel pump is
Easy and cheap and works
Saves money in case it is some thing else like a clogged fuel line or the sock on the tank pick up is clogged.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Always troubleshoot before replacing parts. Otherwise you'll just be chasing your tail and possibly loosing better quality parts in the process.

It's really pretty easy to check the system to isolate the problem.
Disconnect the suction hose from the fuel pump and point it into a can, bottle, or jug. Take your air hose and a rag to seal it, and sort of pressurize the tank from the filler neck. If everything is clear, you should get a good stream of fuel into your catch-can. If it's not clear, you won't.
Also, if there's a leak in the suction line (between the tank and pump) it'll be obvious now. You'll see fuel squirting out of the leak.

If all this checks out, you should connect your vacuum gauge to the fuel pump. Most portable automotive vacuum gauges have a fuel pump scale just for this purpose.

This troubleshooting process may sound like a lot of bother, but it's worth the trouble. Good quality older parts will usually outperform the new junk parts.
 

bronconut73

Bronco Guru
Joined
Aug 7, 2012
Messages
9,916
I tried Holley and Edelbrock mechanical fuel pumps. They only lasted a few years.
I bought a Carter mechanical fuel pump from Summit. Ran it for about 15 years, until recently in fact.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,833
That can also be a failing suction hose/line or even the selector valve under the seat is leaking air into the pump. Clogged suction screen in the tank, pinched fuel line, etc. I would start with changing the rubber suction hose and run it out of a gas can. Does it appear to pump good out of the can? Disconnect the line off the filter and put that into a catch can. Start the engine, it will run off the fuel bowl. I think it should pump a pint in 30 seconds or something like that. If it fails after all that, time for a new one.

Or if it is leaking onto the ground or into the crankcase it is time for a new one as well.

But you might just need a buck worth of new rubber hose instead of a new pump.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
Don't buy a Carter mechanical fuel pump the components inside are junk. My last one lasted 2 years. The Carter before that was well over 10 years. The replacement I just bought was Airtex hoping for better results.

I just tore the Carter apart and the suction valve was just horrible. The diaphragm looked good though. I'll try to post pictures if my old brain works later today.
 

savage

Contributor
Bronco Nut
Joined
Apr 18, 2007
Messages
2,482
Loc.
Renton
Don't buy a Carter mechanical fuel pump the components inside are junk. My last one lasted 2 years. The Carter before that was well over 10 years. The replacement I just bought was Airtex hoping for better results.

I just tore the Carter apart and the suction valve was just horrible. The diaphragm looked good though. I'll try to post pictures if my old brain works later today.
I had trouble with the Carter pump, it lasted 2 months. Bought a Airtex and it's still running strong.
 
OP
OP
Tony Mele

Tony Mele

Jr. Member
Joined
Apr 3, 2016
Messages
132
Thanks everyone. I really do appreciate the perspective in the advice. I actually have done most of the troubleshooting suggested here already. Checked all of the lines and everything from the tank on up to the front end. Everything seems fine until I hit the fuel pump. Even that seems to be okay at idle. But the moment I increase the revs it begins to fail. I've got a clear fuel filter just before the carburetor and I can watch the thing literally go dry.
 

ransil

Bronco Guru
Joined
Sep 6, 2003
Messages
8,122
Could be sucking air.
Put a vacuim on it and see if you can draw fuel

Sent from my SM-G920V using Tapatalk
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
Carter fuel pump valve pictures. This pump was 2 years old with less than 2000 miles on it. Made in China for Carter. The disassembled valve is on the suction side. The center hole in the valve is way oversize and with the spring off center pushing the disc over there was an open leak that didn't seal the valve and allowed the pump suction not to work. P.O.S Changed to an Airtex pump so we will see how that goes. Its made in China too.
 

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Tony Mele

Tony Mele

Jr. Member
Joined
Apr 3, 2016
Messages
132
New Edelbrock fuel pump installed. Went that route cuz it has a pressure regulator set at 6 lb. Read some mixed reviews but let's see what happens. Anyway the problem seems fixed. Trucks running smooth as silk
 
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