Rep Power: 350

Ok, so I installed my fuel pressure regulator two nights ago and ran my return line finally. We set the base pressure at 45 psi. I had spoken with my tuner and he suggested that I keep the vac line off the regulator until I could tune so that I wouldn't be too rich under boost until I could get retuned.

Well after install, I left the vacuum nipple on the regulator open. Car ran like total *** and booged everytime I gave throttle.

Word to the wise, if you run an adjustable vac referenced fpr, make sure to utilize the vacuum nipple. Apparently, when the engine sees load, the regulator has to adjust for the fuel being consumed. Being that its obviously spring loaded, it has to keep the diaphragm down to compensate for load. Being as our stock systems aren't vac referenced, this was a foreign concept to me but it now makes perfect sense.

Also, for anyone running an aeromotive, do you hear any whining coming from your fprs? I hear a whine and its annoying as hell, lol.

 
Rep Power: 388

I've always taken into account that if it has a connection it should be connected each time i've been told otherwise it never worked right so you were right. Good luck and lets see the new tune man

 
Rep Power: 329

no whining in my FPRS are you sure it isn't your pump?
Or some times the line coming from the tank gets dry cause isn't big enough to run that much fuel needed but it only be when you are diving on reving 4k rpm's or up.

 
Rep Power: 297

I have an aeromotive and it doesnt whine. At most all I hear is a slight hissing and the ticking of the injectors.

 
Rep Power: 303

ya adj fprs are vac refferenced. i have had plenty of experience with that on my old truck. glad to see things are comming together andy. cant wait to see the finished product. you and mex make me jealous. i want boost. but as said before patience is a virtue. i am saving to build my old b18b for the dc 4 i bought. swapped in a b20b for the time being. its nice having some bottom end LOL you dont realize how much your missing in the vic until you drive something with more power.
it would have been fun to tinker with boost on the d17 but i have a much better platform now. but i still enjoy seeing you guys pioneer this industry.

 
Rep Power: 238

Mine makes no sound at all. But then again i am running 3/8"ID aluminum fuel line from the tank to the pump and to the fpr.

And my FPR is before the rail. It has its own fuel feed lines to the injectors and its own return line.

 
Rep Power: 0

Told you so.

 
Rep Power: 302

whats the best fpr out there?

 
Rep Power: 238

depends on your application....

Mine was the best for me because it feeds both fuel rails directly from the regulator and has its own return line. I didnt have to weld a fitting to the stock one like most others do.

But mine is a 2:1 ratio fpr with an input and 3 output ports (-8an) and a return port (-8an) and is adjustable past 100 psi.

 
Rep Power: 350

Ok, so I have everything routed correctly, I'm about 99% sure everything is hooked up correctly. Yet I'm still having problems. The car bogs under any load as if there is a dead cylinder.

After talking to Gery tonight and explaining the setup, he seems to think that the fact I'm using the stock line as the return (being so small) and a hose for a -6 fitting for the feed (significantly bigger) is the culprit causing the fuel pressure to fluctuate because the return can't get the fuel back to the tank quickly enough to give consistant pressure. Anyone have similar issues with this or any other insight?

 
Rep Power: 238

thats not it.....

Mine runs perfectly fine with the stock line as the return. It may be a defect with the regulator. Try swapping it out and see what happens.

The stock return line is calculated to be able to support a return for more than 400 hp. It should have no problems.....

 
Rep Power: 305

hm i have the opposite setup.. stock line is the feed and the ssb line is the return. my first regulator wouldnt hold pressure so i swapped it out with a new one and it works fine. only whine i hear is the initial startup when it pressurizes. Willing to bet that the reg is bad.

 
Rep Power: 350

I wonder if its the regulator itself. First thing tomorrow, I'll be checking the pressure with a gauge at idle and while giving throttle to see if the pressure fluctuates. If it does, I'll run a larger line and see what happens. If that isn't the issue, I'll have to see about getting another regulator although this one is brand spanking new.....(I doubt the regulator is the problem.)
And here's the really weird thing. The whining from the regulator was due to an improper seal at the tank lid. So that was causing hiccups this afternoon but other than that, it ran great. Only differences since were; removing the stock fpr and putting a hose in its place and sealing the tank properly.....
I get the feeling if I put the stock fpr back on it'd run perfectly.

 
Rep Power: 305

yeah i know how you feel.. the back and forth thing is so tiresome. I got so agrivated that my car wouldnt start with that 1st FPR i even sent the rail back to have another bung welded on when come to find out it was the regulator all along. **** happens I guess. goodluck.

 
Rep Power: 303

i would be willing to bet its the regulator as well. if it couldnt return the fuel fast enought to the tank you would have a higher pressure than you are trying to achieve making the car run rich. if its bogging that could be the issue though. what are your afr's under load when it starts to bog???

 
Rep Power: 350

Unless the throttle is ever so slight, it bogs. Under anything over like 40 percent throttle, the a/f's jump to like 10:1.

I'm about to throw a bigger hose on for the return line in a few minutes. I am thinking this should solve the problem, we will see.

 
Rep Power: 297

Myika, its not all about HP, If you have a 1000gph fuel pump pumping at 50 psi and a 100gph pump at 50psi the volume delivered is much greater with the 1000gph pump, thus requiring a bigger return line. The more you pump up, the more you need to pump back. It very well could be the regulator, or just the nature of the setup itself. 6an feed, big aeromotive regulator, and a huge fuel rail. I wouldnt trust a 3/16 ID line to return all that fuel. Its just asking for pressure spikes, esp. on deceleration, IE in between shifts.

 
Rep Power: 350

Well guys, I got the setup correct. Plugs were fouled to the max and the car wouldn't start. I swapped plugs and found I had a misfire on #4. Turns out that injector is shot and not spraying. I'll be working on getting it repaired or replaced next week, we'll see what happens.

 
Rep Power: 0

Ouch. Lucky you caught that Andy. Coulda been another motor mishap.

So a faulty injector and some fouled plugs huh? What AFR were you tuned to Andy?

 
Rep Power: 0

Here's a little reading on fuel pressure regulators. There are also links at the bottom of the page.

http://www.shonutperformance.com/FPR.htm

 
Rep Power: 279

Well least we got it up and running. Hope you get you injector worked out, you call Rc and see if they would fix it? or what? Im still checking on that SRT thing, cause im really currious of it! lol.

 
Rep Power: 350

Nah, RC isnt open today. I'll call first thing monday and see what they're willing to do.

 
Rep Power: 297

I hope they'd be cool about it. For as much as those things cost and the limited amount you ran it they should fix it or replace it for damn near nothing, hehe.

 
Rep Power: 327

my FPR dont make nosie and im tuned without the vacuum nipple hooked up, seems like i get better results without it

 
Rep Power: 350

Paul-my afr's were around 12-12.5 in boost.

The noise has stopped, it was due to the cap not being sealed all the way, the regulator was bleeding the air out of the lines, it isn't whining anymore.

I think the reason the injector went was due to overuse. Everytime I hit 16 psi+, the injectors were maxing out all the way to redline everytime I pushed it hard past 4300 rpm, they were maxing all the way to redline, not a big surprise. I should have put the regulator in a while back. But I wouldn't think of not using it now, I need it to keep the pressure rising under boost so the injectors aren't having to stress as hard.

 
Rep Power: 238

you failed to remember that you are not returning all of that fuel. you are only returning enough to relieve the pressure. The volume is nott an enormous amount. The-time when the return line is returning the Most fuel is when the car is not running. As you make more power, you are returning Less fuel.

 
Rep Power: 297

exacty, so techically the more HP you are running, the smaller the return could (in theory) be, but in reality it doesnt work that way. At idle you are sipping fuel so I'd guess you'd know right off if it was spiking, it would probably load up a lil. I did some thinking about this. As long as the restriction in the return doesnt equal more than your minimum fuel pressure, it shouldn't matter what size it is. I still wont ever run more than 1/16 smaller on my return lines. I'd still rather be safe and go a lil overkill.

 
Rep Power: 0

That seems like a pretty aggressive of a tune.

 
Rep Power: 297

^ wish I could tune my car that lean. Temp changes here are so drastic I end up running 11.0 in the few months of summer we have, if I dont retune. Better safe than sorry though. Cape Cod weather = poop. Anything under 11.8ish on 93 is ok for me.

 
Rep Power: 350

Well, I am thinking I'll be going to Tony Paolo at T-1 when I retune. I've heard nothing but good things about him. While he's not the cheapest I can get, for the amount of power I'm going for, I need a safe, good, reliable tune.

750's are being ordered this week. FPR is working right. All I need to do is get the cam, springs and retainers in the head, then I can retune. Probably the week after this coming I'll be heading that way.