Hey all, I recently put in a set of the accel 24lb injectors into my 89 GTA. Been trying to get a pin point on what to set the fuel pressure at, currently im set to 39-38 psi. From what ive been told by my cousin 37.5 is what his injector flow chart is recommending. If i go any lower in pressure, as it revs up and the car comes back down to idle, it drops rpm and comes back up.

Also, out of 3 high rpm pulls, 1 of them it broke up and started sputtering. The other 2 were perfect. Im wondering if a vacuum leak can cause this also?

Any pointers would be great. TIA

 

You need a tune for anything larger than stock. The injectors are not designed to run at lower than about 39 psi (Ford pressure). They are designed to work properly and have the published voltage offsets, low/high PW flow characteristics, etc at the recommended pressure.

Adjusting the fuel pressure is not a suitable replacement for a proper tune. The results are unpredictable and drive-ability, economy, and smooth operation will ultimately suffer. Especially going to lower pressures - this dramatically affects the voltage offsets.

GD

 

not sure if this is the part number you have. but holley has the offset specs

https://documents.holley.com/accel_i...ons_150124.pdf