Is this correct?

1. Adjusting AFPR (Aeromotive 13101). - Remove the vacuum hose while the car is idling and adjust for desired pressure, I was going to set it at about 45psi, and then fine tune the pressure during a dyno tune session.

2. The pump when it primes with the car not running should pressurize the system to about 40psi and bleed off fairly slowly ???

3. What would be a "normal" idle fuel pressure range?

Background, new motor parallel fuel system. Single Racetronix In-tank Walbro 255 feeding a y block which goes to the end of each rail. Each rail is then connected to an Aeromotive 13101 regulator using side 6AN fittings. Fuel is returned to the tank using the bottom 6AN fitting.

So far can't get the pressure to adjust above 30psi and I have a serious bleed down issue.

 

how do you have the fuel pressure regulator hooked up? the return line is coming of that correct?

 

Yes, return is the bottom 6AN port on the regulator going back to the tank.

I've been thinking about the fuel system and now have another question. Long story short after thinking about my symptoms, (Insufficient Pressure, quick leak down, and no gas in the FPR vacuum line), I pulled my tank thinking I probably had a leak in the plastic hose coming off of the fuel pump to the hard line on the sender unit. Anyways it looks fine, so I'm in the process of trying a replacement pump that I have. Basically what I'm saying is that I ruled out the FPR as a possible problem.

I started thinking about it some more and the regulator I have is a bypass type. So wouldn't it be possible that if it was malfunctioning, that it was allowing fuel to return to the tank before it should. That could cause bleed down and low pressure. Anyways maybe I'm off here but now I'm thinking that the regulator could be a problem as well.

 

what i was getting to is it sounds like its either bypassing the regulator, or for some reason running strait through it.

 

Yep and five will probably get me ten that I pulled the tank and the pump for nothing. Again the good ole LT1 three finger salute.

 

Little update for those that may have this prob in the future. The regulator was indeed bad. Brand new from Aeromotive. Basically regulator was just allowing all fuel to return straight to the tank.

 

glad you got it fixed

 

The Aeroquip AFPR's have been a problem for about 4 years now. A couple years ago one of their people signed up here and posted a "free replacement - no questions asked" on the Aeroquip AFPR's.

1. You set the fuel pressure, no vacuum line, to the stock 43.5psi. Best thing to do is leave it there, and tune the right way with the chip.

2. Yes

3. At idle with the vacuum line connected, the pressure will drop from the "no vacuum" level proportional to intake manifold vacuum. With a stock cam, that would be a 6 to 8psi drop. With a more radical cam, you will see less of a drop, since you will be pulling less vacuum.