New Fuel Pump Time

[Ernest]

Given all the tuning i've done with my new 650 vacsec 4150 carb to get my ZZ4 running right, mid throttle ping persists, even with stock timing(10initial/32total/3000rpm), plugs(mr43lts) set to .045 gap, i decided to finally check on the fuel system.

I bought a Mr Gasket fuel guage adapter that splices into the fuel line, placed it in between the fuel filter and carburator, also bought the Mr Gasket fuel pressure guage(15psi), used teflon paste on the 1/8'' npt threads to seal the guage to the adapter, ran the engine and the needle bounces in both directions between 5psi and the max of 15psi, to confirm this madness, i connected an actron vacuum/fuel pressure guage, and that pegged at 10psi. max reading.

Even though the carburator float setting never changes, no fuel dribbling out of the straight leg boosters, this fuel pump definately needs replacement IMO, i dont plan on installing one of those holley adjustable fuel regulators that dead heads the fuel for i havent a return line to the gas tank, and besides, i've read it can cause the fuel to heat up and add methanol to the mix, noppers.

Pictures of fuel gauges and in action below.

Any advice on brand name and trusted 5-6 psi stock like mechanical pump?


Thanks

 

[78Delta88]

Delphi Automotive Fuel Pump MF0001 would be a possibility. It designed for q-jet.

O'Reilly's has it for about $25.00

 

[Ernest]

I went with the $24.00 CARTER brand, designated for a 1979 malibu with a 350cid engine even though mine came originally with a 4.4L v8 from NAPA.... i'll put it in this weekend and see how it goes, pressure wise and as well as on the road.