[Pro Street Garry]

I’m running two Holley 600 carbs with a regulator, my old fuel pump has been leaking for a while now so I put a new one on Holley #510-12-801-1 it is rated for 7PSI. My question is on how I have everything set up. One 3/8 line going to the regulator and two 3/8 lines coming out of it, one of the “out” lines has a fuel gage and the other just runs to the other carb. When I run the car the gage reads around 4PSI no matter how I adjust it. Does this mean that its showing me the PSI to just the one carb and the other carb is getting another 4 PSI OR is it a total of 4 PSI for both? Another question is it possable to lose 3 PSI in the line if pump is at the rear of the car?

Thanks guys Garry

[PRO1CAMARO]

The 4 psi after the regulator would be the total psi output to both carbs. Both carbs would see 4psi.

[Fred Ficarra]

Sounds like the fuel pump is set at 4 psi. The regulator can't raise that pressure, only lower it. And the pressure at the carbs shouldn't be much lower than at the rear pump. 3/8 line is used to reduce friction loss, not to provide massive amounts of fuel. A 3/8 line will support about 2500 horse power. The amount of fuel that gets into the carb is small. Just check out your needle and seat. That amounts to little more than a squirt gun.

[Pro Street Garry]

Thanks guys

I had 6 ½ -7 PSI with the old pump. I tried to get the same pump as before but the part # came up empty (20 year old Holley) Maybe it was a 14 PSI regulated down?

I thought I read somewhere that anything less than 5 PSI is N/G, is this true?

Maybe I got a bad pump...it says in the paperwork "Preset to approximately 7 psi"

[ZZ430DropTop67RS]

Garry, I was wondering what kind of gauge you are using to check this.

If it's one of those 2 inch gauges that screws into the line, they are famous for being off.

I would try a temporary quality test gauge.

Edit: I just saw your last post.