Suggestions for reducing flow through purge valve

[CharlieC]

Howdy guys,

Here's what I have. I run a check valve based conversion with one solenoid valve as a purge valve. The purge valve is hooked up to a timer. The shortest amount that I can set the timer to is about 8 seconds. However, I only need a 3 or 4 second purge (tops) to clear the veg out of my system. In 8 seconds, I push almost a quart of fuel (3/4 of it d2) back to my veg tank. This seems like a waste of diesel.

I have been experimenting with using a ball valve to reduce the flow of fuel, but I was wondering if anyone had other ideas about slowing down the flow of fuel so that in my 8 second purge, I only move about half as much fuel as I am now?

Would it work to put a FPR on the return line? This seems expensive, but would regulate the flow of fuel. Other thoughts?

Thanks!

[ridiculously_necessary]

i would just bottleneck it somehow. look around on mcmaster site fo rsomething you can slip into the line that has like an 1/8" inside diameter or whatever is appropriate.

[mankypro]

I use a brass ball valve and turn it until my purge pressure is 10psi - enough to make the engine still run without chugging and leave it there...

[ridiculously_necessary]

maybe a needle valve? - i think thats what they are called...

[simone0414]

I agree with Manky. Just use a manual ball valve. Low maintenance & once it is set your done. That's what I use & works fine.

[tubular031]

I have a ball valve after the purge valve and have it about half shut. This chokes it enough to keep the fuel psi at about 15 when purging and also is a safety. if my purge valve were to fail on me I would not be able to drive, but since my ball valve is there I can shut it and keep driving. EVERYONE should have a ball valve AFTER the purge valve as a safte. or at least a way to pull the purge line and plug it.

dang it was so clean under there when it was new!

[simone0414]

My ball valve has saved me. My purge valve stuck open a while ago. If I didn't have the ball valve there I would have been done.

[CharlieC]

Cool, thanks guys! I threw a ball valve in and am messing around with how open to keep it. At an 8 second purge, wide open throws about 4x as much fuel through it as needs to be purged. At half open, I got a hard start. Fine tuning it now. Let's just hope it stays put once I set it. PSD's arent exactly vibration free...

I appreciate the input.

[tubular031]

35k or so miles now and mine has not moved at all.