Fuel system question.
 

hey guys, since swapping to a 350 ive been having nothing buy problems with my fuel system. I had a question for you guys on this subject matter since im positive i dont know as much as you guys on this.
Originally the motor was built with 24lb SVO injectors, i later found out that because ford runs a 35psi and thirdgens run at 41psi, that my 24lb SVO injectors became 26-28lb injectors. I bought some 24lb bosch injectors from southbay and it made the car have more power, runs better and the whole 9 yards. I was doing burnouts from a standstill and chirping into 2ns gear, then i found out that i was also sporting a fuel leak at the FPR, replaced the O-ring and sealed up the leak, but now i'm not burning out as much, seems the response time of the motor is slowed.
my question is should i get an adjustable FPR and lower the pressure? or are my 24lb injectors too much? should i go back to 22lbs? or is the car running the way it is supposed to and going to less fuel would be worse for the motor?


my engine setup is:
350 tpi, aluminum summit heads, bosch 24lb injectors, accel base, slp runners, hooker headers, crane 2032 cam, tuned performance custom tune. i always seem to forget about tiny stuff also done to the motor but thats the main things done to it

Re: Fuel system question.
 

Did you recheck your fuel pressure after you fixed the leak?

Yes, pressure is at about 40 psi

Re: Fuel system question.
 

i'd go for the adjustable FPR and crank it up. i'm no expert but in my experience FI motors generally respond better with higher pressures.

Re: Fuel system question.
 

but wouldnt that then make me run at a higher lb/hr rate? i'm concerned the problem is too much fuel for my setup, unless this is the right amount. I would go back to 22lb injectors but i'm concerned id burn up the pistons somewhat quickly.

Re: Fuel system question.
 

does the car smell like it's running rich? how do your plugs look? is the timing correct? is your TPS set right? could be something simple? but i wouldnt be afraid to crank the FP up to 50psi.

Re: Fuel system question.
 

NO! the Ford are rated at 43.5psi They are rated the same as the GM

Re: Fuel system question.
 

It will run better if you get the injector size re-adjusted in the tune for 24lb injectors

It smells rich, but it sorta always has. I haven't pulled the plugs yet but I'm sure after all summer of it running rich they'd be kinda black. Tps should be right, not sure how to set it, don't have a scanner. And if I get an afpr I'll see about cranking it

When I was doing my research for a while I found a few pages saying they run at 35 psi. Either way after putting 24lb Bosch injectors in, the car ran better, and didn't smell as rich as it was running with the svo's. The prom is tuned for 24lb injectors.

If I got an afpr, would it be ok to lower the pressure? I'm afraid too lean would wind up burning up the Pistons or run the engine too hot.

Any thoughts?

Re: Fuel system question.
 

The ECM will compensate the inj PW for higher or lower pressure...that said, you lose atomization as you lower the fuel pressure.

I'd start off with a scan tool and see what's up, if in fact it's been running rich before, you may have fouled the O2 sensor.

It's a brand new o2 sensor. It does have a home made cool air intake, so maybe it's cuz of pulling too much air that it's been running rich. But you guys don't think 24lb is too much for my setup?

Re: Fuel system question.
 

Naw...can never have too much air:)

Only way to tell for sure, would be to plug in and see what the ECM is seeing..even though the chip was burned for 24lb/hr injectors, you still need to take a look to see what's going on.

Re: Fuel system question.
 

ok thanks guys, I have an ALDL cable, but could never get it to work....maybe i'll try selling it and get like an obd1 scanner. thanks guys.