Thread: Injector tuning ?

I'm installing 42lb injectors tomorrow.
And of course tuning it for the bigger injectors.
But i also have a fuel pump rewire kit coming on thursday.
Question.
If i install the injectors and tune.
Would i have to retune once i install the fuel pump rewire kit again?
Would installing that fuel pump rewire kit throw my tune off?
Since its supposed to increase the fuel flow.

you shouldnt have to retune for the fuel pump rewire.

Originally Posted by Bio248

you shouldnt have to retune for the fuel pump rewire.

He might. When I did the resistor bypass, I had to do some serious tuning to fix the very negative fuel trims. I would think that the same would apply to the rewire to a lesser degree.

its possible, but i cant see it doing much at all except on the top end where it is the only place youre losing fuel due to low voltages.

Originally Posted by Bio248

its possible, but i cant see it doing much at all except on the top end where it is the only place youre losing fuel due to low voltages.

But the system will be sitting at a higher pressure any time the engine is running. More fuel will be injected for the same pulse width, and the fuel trim will have to go negative as the PCM compensates.

It may or may not move your trims significantly. You'll just have to do it and see. At the worst one or two MAF tunes would do it.

Ok thanx for the info guys.

Originally Posted by TDCRacing

I can see where everyone is comming from. It seems like the only place that it would make a difference would be where you were not getting enough fuel at before. But I see these other guy's points also.



Be sure to put that 42.5 IFR table in the pcm also. I have one if you need it.

I think the guys tuning me has one.
If not, i'll pm you.
Thanx!

Originally Posted by TDCRacing

I have one if you need it.

I will soon. Care to copy me one?

Good info, thanx for ur help!