Fuel pump woes

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RayW
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Joined: Sat Jul 22, 2023 5:50 pm
Location: SE PA

Fuel pump woes

Post by RayW »

Just thought I’d share my recent fuel pump woes in case it could help anyone. I recently had to replace two old failing fuel pumps— one on my 73 Commando 304 and one on my 70 Wagoneer 350 Buick. First, I ordered a Delphi fuel pump for the 304. After start up, engine sounded like it had a horrific valve tap. It was the fuel pump— rocker arm just rattled up and down. Ordered a Carter. Installed the Carter only to find the outlet fitting barely threaded, not even enough threads to tighten the flare nut. Received replacement Carter. Ran fine for a minute, then started idling roughly with fuel coming out of the MC 2100 vents (rebuilt carb BTW). Put my vacuum/fuel pressure gauge on the pump and 10 lbs of pressure (maxed out the gauge). Returned the Carter and ordered a Crown. Same thing— flooding, etc. Fuel pressure gauge again was pegged at 10 psi. Tried a regulator, but with no place for the excess fuel to go, gas just leaked out around the fuel pump bowl where it was crimped to the body of the pump. Fortunately Carl Walck had an old nos Carter pump from probably the 80’s made in Canada. Installed the old Carter and it runs beautifully. 4.5 lbs of pressure from the pump, smooth idle, no flooding or running rich— car’s been running great. Now for the Wagoneer. New Carter pump, same rough idle, flooding, etc. This Carter is putting out 9 lbs of pressure. TSM calls for no more than 5.5 lbs. The Wagoneer fuel pump has a return, so installing a regulator set to 5.5 lbs has been working fine and the Wagoneer has been running great. That’s 5 new pumps, and not one performing to the application’s OE specs. Are there any good, new fuel pumps out there?
1971 Wagoneer, Buick 350, TH400/D20
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