Ok as more and more people install adjustable Fuel Pressure Regulators what do you run your Fuel Pressure at.

I orginally installed mine to run with my larger injectors but have since removed the larger injectors and went back to 15# injectors. I have one of the watts fuel pressure guages on my fuel rail so I can moniter fuel pressure.

I have turned it down to 30psi running idle with vaccume applied and 40psi WOT with Zero Vaccume applied. I am trying to squeeze a few more MPG out of the car when doing the daily commute to and from work.
Becuase my FPR can be adjusted at a whim without tools and while the car is running I have no problems turning it up on the weekends.

Currently I spend 30min per day in Stop and Go traffic so the car spends a great deal of time idling in traffic. I have an O2 meter on the dash that says it is not running lean and pretty much stays Stoich.

Oh and the timming is retarded a bit and running on 87oct gas. Cranking compression is 160-170 across the board compression is around 9.5 - 1.

------------------
85GT 2.9 4spd MSD Everything, Big Cam and Nitrous. www.captfiero.com

That's pretty lean for a 2.8. I think you will find that your fuel mileage and power may increase if you increase the pressure 5 to 7 psi. The stock 2.8 usually runs at about 40 idle and 45 or so at WOT. Since you can change it so easily, I'd give it a try. Hope that helps.

Phil

------------------
87 FIERO GT 2.8 5spd

GM auto tech for 27 years. Specializing in electrical and computer problems. Now on workers comp. and it looks like I will be unable to return to work as a tech.

GTDUDE is correct. your pressure is much too low. You need to bump it up. GM service manual calls for over 36 psi so you are way under. I think its actually around 36-42 psi or something like that. You are probably getting a horrible spray pattern cause of this too. EFI needs over 35 psi to really work properly. Dont' know why you turned it down so low.

Went back to stock injectors. Take your nitrous off?

------------------

newbie extreme

I'm running 6.0 psi on my 3.4L. Line pressure never drops below 5.0 psi.
(This is for a carb, not F/I)

As mentioned above, Turning your fuel pressure down that low will cause a leaner condition and worse mileage.
Leaner running will cause the engine to run hotter, Pinging/knocking will occur more during hot days, poor spray pattern will cause your emissions to get worse.

Isn't the GM spec pressure rated with the engine off and no vacuume to the regulater. Which causes high fuel pressure.

I will turn it up to 36psi for the run to work tomorrow then. I have not noticed any ill effects running it this low, but if ya'all think it is doing more harm than good then I will crank it up before I leave in the morning. (Large wheel that I spin with my finger to increase it and watch the pressure increase on the gauge)

As for the Nitrous Comment. Ya I pulled the Nitrous Kit off of the car over the winter. I was in a minor accident. Some guy pulled out in front of me and I T-Boned him. Even though it is not against the law, the local Insurance frowns apon Nitrous Kits in Cars, and I felt it was in my best interest to remove the entire thing. Pulling the injectors was just in hope of getting better gas mileage and without the Nitrous Kit in the car I did not nead them anyway. I will be re-installing it all come spring.