Hi all,
What is the highest reasonable fuel pressure I can use for stock injectors? I am getting a drop off on O2 readings, starting at 840 first frame, 808,789,769,753,then back up to 785,781, then 765, where I get my first retard [2.1, 18 lbs, 86 mph]. It's a hot wired Buick Park Ave. Ultra pump, stock turbo.
Thanks,
Bob Dawson
87GN
96SS
I wouldn't use any more than 50-52 psi (hose off, base pressure).... and only for the track. If you have to run that much on the street, then you have:
- Chip that doesn't get the injector duty cycle high enough
- Not enough fuel pump (that would be a suspect, since you are using a stock replacement pump)
I thought the Buick Park Ave. Ultra pump was equivalent to some of the better aftermarket pumps. That what Zak told me when I bought it. Does anyone know the specs on this pump?
Thanks,
Bob Dawson
SOUND LIKE YOUR YOUR NUMBERS ARE OK,I USED STOCK
INJ UNTIL THIS YEAR. 50LBS VACUUM LINE OFF AND MONITOR YOUR 02 READINGS CONSTANTLY YOU MAY HAVE TO DROP THE BOOST SOMETIME.
Don't think that pump is listed, but there are a lot compared at http://www.gnttype.org/techarea/fuelsystem/fuelpage.html and you might get some info from checking it out.
Should the fuel pressure be set with the vacuum line off the regulator or on. What should the pressure be for a mildly modified GN? (exhaust, fuel pump, chip) thanks.