I just rebuilt my engine and put in a primary fuel rail with 750cc injectors. My old fuel set up was 1600-850. I have the PFC. So i changed the injectors on the computer to 750's to see if it would richen up. It didn't. I was wondering if i should maybe drop it to 650 or 550 in the computer?
If Anyone who knows the PFC could chime in it would be greatly appreciated.
Yes i do know that the car will have to be re-tunned but i need advice for until then.

 

When I switched to 850cc primaries, there was another setting that I had to change as well as the injector size. I don't remember exactly, but I think it was the duty cycle. You might want to try increasing that. It was on the same page as the injector size setting with the datalogit.

Also try posting in the PowerFC section.

 

What if i don't have a Data log it? can it still be controlled with the commander?

 

Where did you get the 750's? How are you measuring your air to fuel ratio? I would look into those injectors...

 

You are trying to tune by changing the reported injector sizes? That is going to change fuel delivery everywhere, which is not what you want. Even with the Commander you can adjust fuel on a cell by cell basis.

How are you measuring AFRs and where is it running rich?

 

I am measuring AFRs through a wideband O2 sensor. It goes to 13.5-14.6-15 + thats why im not driving it

 

yeah that's super lean under boost...play it safe and get it tuned

 

This is not under boost. This is under normal driving. I'm about to go get top feed 850cc injectors tomorrow to see if this will fix the problem.

 

a bigger injector isnt gonna cause it to magically get richer, you need to tell the pfc ur not using the stock injectors and then tune it to get more fuel.