Adjustable fuel pressure regulator
08-14-2002, 06:14 PM
#1
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Location: Annandale, VA
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Adjustable fuel pressure regulator
I just tried to install an adjustable fuel pressure regulator on my 91 S2. The regulator mounts up perfectly to the fuel rail, but the billet housing is about an 1/8th of an inch to big. It hits the intake manifold and won't allow me to re-install the fuel rail properly.
Has anyone had this problem? If so what was your solution. Or if you you have one installed (and didn't have this problem) where did you purchase yours? Thanks
Has anyone had this problem? If so what was your solution. Or if you you have one installed (and didn't have this problem) where did you purchase yours? Thanks
08-14-2002, 09:01 PM
#3
Race Director
The S2 FPR is a bolt-on unit, unlike the clamp-on barb type used in the 951. And it goes into the end of the fuel-rail rather than on top like the 951. I'm not sure if you can flip it around and have the mounting holes line up. And I know for sure the fuel-line isn' t long enough to reach around the other side.
What are you using and adjustable FPR on an S2 for anyway? The thing's already way too rich at full-throttle anyway...
What are you using and adjustable FPR on an S2 for anyway? The thing's already way too rich at full-throttle anyway...
08-15-2002, 01:30 AM
#4
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I get a detonation above 3500 rpm when I really get on it, on hotter days. The timing is correct and it doesn't do it on the cooler days say 75 and below. I think the compression was raised slightly when the motor was balanced and blue printed (done by the P.O.). I wanted to try this before possible pulling the head. I don't even drive it on hot days now.
08-15-2002, 01:53 AM
#5
Race Director
What you really need to do is test your air-fuel ratio on the dyno. If it's between 11-12:1 then you'll lose power by going any richer. The next step is to check your air-temp sensor to make sure it's operating correctly. One feature the DME code has is the ability to adjust ignition timing based upon air-temperatures.
Next, check out the chips you have in the DME box. I fought an S2 for close to 10-hours in trying to dial in a fuel mixture only to find out it had aftermarket chips. Swapping those out for stock chips really helped.
Some aftermarket chip programmers will actually disable the ignition-timing adjustment based upon air-temperatures <img src="graemlins/nono.gif" border="0" alt="[nono]" /> . Probably a last-ditch effort to dial in an optimal air-fuel mixture based upon testing spread across several days. However, by removing this feature, you've removed one of the safety as well as performance features of the car.
Also check out both knock-sensors on your car as well. If one of them fails, it will cause the DME's knock-detection feature to be erratic.
So adjusting fuel to make up for knock is really a cover-up, sweep-it-all-under-the-rug solution that may be ignoring the true causes of your problem. Good luck !
Next, check out the chips you have in the DME box. I fought an S2 for close to 10-hours in trying to dial in a fuel mixture only to find out it had aftermarket chips. Swapping those out for stock chips really helped.
Some aftermarket chip programmers will actually disable the ignition-timing adjustment based upon air-temperatures <img src="graemlins/nono.gif" border="0" alt="[nono]" /> . Probably a last-ditch effort to dial in an optimal air-fuel mixture based upon testing spread across several days. However, by removing this feature, you've removed one of the safety as well as performance features of the car.
Also check out both knock-sensors on your car as well. If one of them fails, it will cause the DME's knock-detection feature to be erratic.
So adjusting fuel to make up for knock is really a cover-up, sweep-it-all-under-the-rug solution that may be ignoring the true causes of your problem. Good luck !