[140HORSE]

My girlfriend has a 93 fox with a FI 351, .40 over, pro chomp heads, mild cam???, edelbrock victor5.0 intake & 42lb inj. It seemed super rich at idle and while cruising so the fuel pressure gauge said 42 psi with the vacuum out. I turned it down to 35 and seemed a lot better and it never popped or leaned out all the way to 6000rpm and even the plugs looked clean with a bronze strap. My ? Is sometimes the fuel pressure drops to 29 while cruising, is 35-29 psi too low for FI? I'm pretty new to the injected stuff, as always, any help is greatly appreciated.

 

[outlawcoupe]

42 seems like a lot of injector for a mild NA 351. With that much injector if the MAF is off at all it could cause issues. I would have it put on a chassis dyno and maybe have a chip burnt for it.

 

[140HORSE]

Thanks man, I agree. The previous owner had a n2o kit on it and I guess he thought the bigger inj would be better. HED is only a half hour away so we are deaf gonna get some Dyno time

 

[GilroyRacing]

38-42 is normal

 

[GilroyRacing]

Is there a tune/chip/programmer on the car?

 

[140HORSE]

Not that I'm aware of, and I know the previous owner pretty well and he said he never had it tuned

 

[GilroyRacing]

That is something you should look into.

 

[140HORSE]

We're def taking it to HED soon. What i'm trying to ask is if 29-35psi is too low? Will the injectors work properly with this psi? Is there anything "bad" that could happen?