hey guys. i installed my 255 high pressure FP about a month ago and since then she's been idleing at 800 or less. she stalled acouple times on me while i was downshifting from 3-2. once i got off the interstate (only doing about 70-75) and she died at the stop light at the end of the off ramp. any advice on what to do would be nice.

oh i've only had this problem since i installed the new FP.

do you have a fuel pressure regulator for that pump?

I have a Walbro 255 and don't have an after market regulator, and I've never had that problem

http://www.fullthrottlespeed.com/Dynamic/i...c=0012GREG&tpc=

'nuff said.

100% agree with you Nate. I have one and would never look back. Though not everyone has the problems as clearly as you do, everyone that runs that pump on the stock FPR is going to overrun to some extent. An AFPR makes every aspect of tuning easier.

DITTO

wouldn't raising my idle work? cause raising the idle and getting the regulator is just flowing more fuel right?

Ok, here's what's happening...

Your flowing(lets say) 5lph to your engine at idle. Your pump is flowing 250lph.
Your FPR is only meant to return 120lph and can hendle 180lph or so efficiently
The extra fuel backs up in the rail and increasing your fuel pressure. Raising the idle will cause the injectors to use up some of that fuel up, but not enough to make the problem go away.

Now comes the real problem. Under boost your FPR is able to work properly because your using enough fuel. Your pressure will drop to 38lbs then raise up by whatever you boost level is. Lets say your running 15psi. Your fuel pressure is now 53psi in the rail. You let off the gas and expect to idle. Your FPR is trying to make 35psi at this point, but the above situation comes into play. Now add the fact that the pressure is already to high in the rail and now, without the injectors sucking fuel is getting higher. Your injectors open back up at 1600 rpm to catch the idle only to find way to much pressure causing a rich mess. Your car chokes out and dies.

How do you fix this. You get yourself an aftermarket FPR with a larger return line.

well put.

so basically i'm flooding my engine because i'm sending too much fuel? and the afpr will regulate it so that i'm not doing this. the funny thing about it is that my air/fuel gauge reads that i'm running lean when i idle...wouldn't that be a lack of fuel/fuel pressure? and does anyone have an AFPR on hand that they'd sell?

do you have a 'blinky' air/fuel gauge? if so, in my opinion those aren't very reliable and are relatively pointless. they're more of a light show than a good way to tune your car. a wide band 02, a good egt, and data logger will really tell what's going on.


that's just my .02

it a sport - comp autometer a/f ratio gauge...it's got 22lcd's ...i guess that's the "blinky" thing...ok so AFPR = No more stalls

One more question before I agree with that statement. Your recirculating your BOV right? If you venting any it will do the same thing.

yeah he's recirulating, not venting, by the way, i have a 255, and have had a 255 for about 3 months now and i'v never had the slightest problem

Rollout...i'm thinking that since you're running a bigger everything than i am ...that's why you don't have this problem but hey i don't know.

I had a 255 when i was on the stock turbo and still had no problems

every car is different.

2G's run a higher base fuel pressure stock, so they have less of a problem with overrunning the regulator.

actually i believe that nate is referring to his 2g.... but, in either case, different carsrespond differently. women.