So, now I am running into a driveability issue with the stroker... 42lb injectors, stock fuel pump (its fine) holley adjustable fuel pressure regulator.

At the dyno, I was running fat, so we just changed the fuel pressure regulator to get it to lean up. (it was just a club dyno day, not tuning day)

I was at 43 psi, now its at 37 with it running and vacuum unhooked.

Will the lower psi cause puddling of the fuel or something? The car likes to surge and buck now at lower rpms (mostly under 1900 rpms) and it didn't do it before.

Yeah, its a bigger cam, but only 23X 23X. It ran with minimal surging before the change at the dyno, now it seems to buck alot and run crappy at low rpms. But, once you get above 2500 rpms it is like I hit the nos or something, it fricken kicks down and hauls. Like I switched gears, but I didn't...

So, what is the optimal PSI to set that bad boy to, then I can tune around that.

THANKS!
(yes I searched, but nothing worth while showed up, just fuel pump questions and non-pertinant things)

 

Set it at stock FP and change the tune for the top end.
37 with no vacuum is about 30PSI which is a bit low to act correctly.

 

As stated above, have the car dyno tuned.

 

In answer to your question about lower pressure causing surging.....in short, yes. Plain and simple.

 

what is stock, 43.5? 47? 49? I have heard so many different numbers lately...

 

43.5 with the vacuum line unhooked.

 

ok cool! THANKS!