Thread: 42# injectors on an 04

Going from stock 04 injectors to 42# Ford injectors is just a matter of doing 36/42 and multiplying that percentage down the whole IFR table, right? This is on the PT table, not the HPT one. I've been reading some other threads that made me think that maybe I needed a different percentage.

Been on vacation, so just getting back to this. I answered some of my questions already. I have this posted over on ClubGP too (ClubGP Message Forum troubleshooting). So, I read the writeup over there (Fuel). Good info. My question I still have, though, is whether I should edit my IFR table in the PT (the "normal" one, not the one that looks backwards) by using the 36/42 ratio or if there's no simple equation to start with on the 04s. I did try that on that table, and my trims were still way negative (usually at least -12). I unplugged the MAF to check my VE tune, and I honestly didn't have much variance there (although I couldn't really push it much due to the amount of KR I got with just slight increase in throttle). I just loaded a MAF tune tonight to correct the huge negative numbers outside of PE, but I'm wondering if my IFR is still out of whack which is why it's having to pull so much fuel (I haven't had an opportunity to drive the car since loading the updated table). I'd like to make sure my IFRs are at least close before heading too far into MAF-land and having to start over again because I started with bad numbers.

its either one way or the other 36/42 or 42/36. i know in DHP versus HPTuners you need to go different directions with the tables to add fuel.

Yeah, I've just read (like on that fueling link) that the 04+ IFR is rather goofy due to the fact that the returnless fuel system causes different flow rates depending on manifold pressure and whatnot. So I wasn't sure if using 36/42 was actually accurate with my setup or not. It also seems odd that I'd be -12 to -17 after importing the IFR changes. It was a stock bin to start with, and the only other parts that were changed were the torque settings and other "initial tweaks" from the WebRacin tune, but none of that was fuel related except for the PE AFR stuff. so it should have been a clean change. Just seems like a large amount to have to alter with the MAF.