gimpyg001

i swapped my 305 tpi for a 350. but used all of my 305 parts. i heard if i install an adjustable fuel regulator it will increase my performance. if so what preasure should i set it to

jstuart83

well just on theory the normal pressure for a 350 is around 43-48 pounds at idle with the #22 injectors so a 305 has #19. Lets just say for example even get close to making a #19 flow as much fuel as a #22 you may have to push the fuel pressure up to around 54-58 psi which is going to put a strain on the injectors and cause the to fail eventually. The best answer for your question change the injectors to a #22. I keep hearing that a #24 ford injector will work on a stock l98 but im waiting on someone to confirm this for me before i believe it. But a # 19 is too small to tap the full potential of your 350, an adjustable fuel pressure regulator may help a little but what you pay for one of those you could get a set of injectors

The Devastator

Your fuel pressure should be set to whatever your chip expects. If you increase or decrease fuel pressure it changes the air/fuel ratio throughout the entire range of operation. What the ecm begins to see is that it isn't creating the AF ratio that is trying to so it dials back pulse width accordingly.

Essentially what happens is your engine runs rich for a split second before the ecm pulls the pulse width back to correct.

An increase in fuel pressure does create an increase in performance by improving atomization up to a point. However your injectors must be engineered to handle the increased pressure and your ecm must also have that base fuel pressure in its fuel tables for its enrichment calculations. Otherwise its going to be hunting all over for its desired AF ratio.

On an OEM setup, too much fuel pressure will cause injectors to be overloaded. This can cause premature injector failure as well as burn out the drivers in the ecm in extreme cases.

I beleive that the 305 and 350s may share the same pph rate injectors however I'm pretty sure that the fuel/spark tables are different. Are you running the same chip on that 350 as the 305?

jstuart83

the 305 uses a #19 injector and the 350 uses a #22 i dont believe there the same pph rate. also according to my factory repair manual unless i read over something and im pretty sure from when i took apart my fuel rail there is no fuel pressure monitoring circuit goint to the ECM, the two major systems that affect the air fuel mixture ratio is from the MAS/MAP sensor and the o2 sensor which is a narrow band used on third generations, only tells the ECM hey im rich or im lean. most newer cars wide band o2 sensors that allow for constaint adjustment more procise reading

gimpyg001

yes everything other than the block and the heads is from the 305. it runs fine. but i put a full msd system on it and i was wondering if i could push anymore out of it

gimpyg001

let my know if the ford injectors will work when you find out. thanks

southbay08

I agree, 19lb for the 305, 22's for the 350. You can actually use the 22's in the 305 but you will not receive optimal mpg.

RED86Z28

You can get Bosh III design 22lb injectors this place. Adjustable regulators are garbage.
http://fuelinjectorconnection.com/sh...&productId=134

southbay08

We can also help with the design lll's, we have plenty in stock.
www.southbayfuelinjectors.com