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Lynn
02-28-2016, 04:08 PM
I just built a mild 350 with a retro roller hydraulic cam. Bought the special fuel pump push rod for roller cam.
I re-used the fuel pump that was on the previous engine as it looked pretty new, and functioned well on the two barrel carb that was on that engine. No leaks and no flooding.

Fired up the new engine and after a few seconds gas just pours out the top of the carb (Q-jet. Removed the carb assuming I had some trash in the needle and seat. All looked good, so put it back together. Just put a pressure tester on the fuel pump and immediately went to 10 psi just cranking. Didn't even bother to start it, as 10 psi is obviously way too much.

My options are: try another fuel pump (but I hate throwing parts at something), install an in line regulator (have never needed a regulator on a stock type fuel pump), or ditch the pump and rod and install a low psi electric pump. If the correct mechanical pump would work, that is my preference.

Anyone else ever encounter something like this?

VintageMusclecar
02-28-2016, 05:05 PM
Yep. Parts store replacement fuel pumps are notorious for excessive fuel pressure. Quadrajets do NOT like anything much over 5.5 to 6 psi MAX. I would be looking into one of the Carter OEM replacement pumps.

earntaz
02-28-2016, 05:11 PM
X2

novadude
02-28-2016, 10:36 PM
I'm using one of these with a q-jet

http://www.summitracing.com/parts/CRT-M6900/

Works good with a .130 needle seat and 5/16" float level. Puts out a bit too much pressure for a larger seat. I never had a gauge on it, but I know I had issues when I tried to go larger with the needle seat. With a stock fuel filter in the Q-jet bowl and 3/8" line, this set-up is good enough for 12.9x @ 108 mph in my Chevy II (355 ci).

VintageMusclecar
03-26-2016, 02:32 PM
What fuel pump did you wind up going with Lynn?

Lynn
01-19-2017, 12:16 AM
Looking at some old posts and ran across this.

Just for the record, I used a Carter M4585 from Rock Auto. $14 and some change.