patooyee

iTrader: (1)

Is there such a thing?

Blown06

iTrader: (32)

Its not the regulator....its the pump style.
If you're that concerned about it, put a check valve in it.

patooyee

iTrader: (1)

Why do you say that?

I have 2 Walbro pumps with built-in check valves. I have redundant check valves after both. The pressure line goes to flow-through rails and then to the Aeromotive regulator.

I have unhooked the pressure line at the rail and dead-headed it to a pressure gauge. That line holds pressure so the pressure isn't going back through the pumps.

I have pulled both rails with injectors in them and pressurized the system. No fuel comes out of the injectors.

I have unhooked the return line from the FPR and turned the system on. It bypasses fuel out the return port starting at 1psi and after I turn the pump off it continues bypassing until pressure reaches zero. (Which takes about 3 seconds.)

I've called Aeromotive about it and they state that their FPR will not hold pressure with the pump off.

It seems pretty definitive to me ...

dw456post

I would like to know the same thing. I have two dw pumps and am regulating before the rails.

dw456post

I guess I will try the -8 Summit check valve. The only thing that it affects is starting. I have to turn the key to on for about 2 seconds before starting, to let the pressure build, otherwise the starter runs too long.

patooyee

iTrader: (1)

Where are you going to put the check valve? The Summit valve has a cracking pressure of 2psi. That means its only going to hold about 2psi in the line. I'm trying a check valve too but I don't think its going to do what I want it to. I'm thinking of changing the internal spring out for a stiffer one to increase the cracking pressure to hopefully hold more in the line. I have a Prime membership so it was cheaper for me to get this than the Summit valve after they charged $10 to ship it :

http://smile.amazon.com/gp/product/B...?ie=UTF8&psc=1

dw456post

I would put it on the fuel rail feed side of the regulator. That would take the return line out of the problem. If the bypass is one way, it should hold pressure in the fuel rails until the engine fires and then the fuel is there to push the valve open as soon as the pressure drops on the fuel rail side. I have a pressure gauge on my regulator and the pressure is immediate as soon as the ignition is turned on. It just takes a couple of seconds to fill the rails---I guess.
Yeah the summit valve is kind of expensive.

patooyee

iTrader: (1)

Please make sure to post back with how it works. I will do the same.

dw456post

I got the Summit check valve and put it in the fuel line between the regulator and the fuel rails. After I shut off the engine and let it sit for a while, it starts right up, no need for 3-4 seconds priming. Keep in mind that I have the regulator BEFORE the fuel rails. I don't know your setup. The 2# is against the pump, when the valve closes, it holds whatever pressure is on the other side (fuel rails).

patooyee

iTrader: (1)

Thanks, I got a new FPR and my problems seem to be solved for the time being.

dw456post

Well, Forget what I said earlier. After letting it sit for a couple of hours, It will not even start. I will be making a new fuel line.
What FPR did you get?

patooyee

iTrader: (1)

http://www.summitracing.com/parts/fue-51502-1

patooyee

iTrader: (1)

Its worth noting that I did disassemble both regulators before installing. The machine quality and seat type were equal / the same in both. I acknowledge that the seat in my original Aeromotive FPR was damaged by myself not having adequate filtration when I first built the system. It was evident where crud had been trapped on the seat and scratched it. But the overall sealing principal of a steel ball on an aluminum seat just doesn't seem like a great sealing method to me and that is evident by the fact that even my new FPR leaks down over time, albeit a much longer period. With the new one I shut the pump off and it immediately drops from 58 to 40 psi. From there I let it sit for 2 days and returned and it was still sitting at about 5 psi, so WAAAAAY better than the damaged Aeromotive.

I have some summit check valves which operate on a similar principal. They have an aluminum seat with a sprung plastic ball that "seals" against the seat. Even this is not a perfect seal though as they are what I have in my supply line and it does leak down over the course of about a week.

Then I got this new Russell check valve. It is different. It has a sprung cup with a rubber o-ring in it that seats against a large machined flat surface inside the body. I feel like this is a much better design for something meant to seal. I don't know for sure because I haven't plumbed it into anything but just for experimental purposes I do intend to put a heavier spring in it to see if I can play with cracking pressure to achieve a higher pressure hold in the system. Everything in my system is -6AN so I won't have to modify anything to install or de-install it. I'll report back once I'm done tinkering ...

dw456post

I took my Summit check valve apart and the ptfe part that seals was off the spring and stuck in the end of the valve, blocking fuel flow. What a piece of crap.
That thing is going back. It's a pain in the rear to change this thing because it is behind the TVS.

dw456post

Here is a pic of the parts that came out. Looks like the white seal was damaged before they sent it to me. Probably a return that they didn't bother to check.

stevieturbo

I've had a non pressure holding system for over 10 years.


Never once has it posed a problem or been the cause of slow starting.

Stop worrying about it.

dw456post

OK, Talked me into it.