I just installed 24# injectors and drove about 2 miles and my check engine light came on. I went to valvoline and they said my mixture was to rich or lean? I thought that if I added a mass air flow that was calibrated for 24# injectors that I would be ok. CAN ANYONE HELP???????????

 

Did you get a superchip or computer reprogrammed. I would guess it is all screwed up with all that extra air and fuel coming in. just my two cents.

 

whoops double post......

 

HI!... higson2 : Why did you change to larger 24lb injectors? Does your engine (modded) require you to run larger injectors. The stock 19LB (orange) injectors can support up to 304H.P (flywheel) at 80% duty cycle. 24LB injectors will support up to 384H.P (flywheel) at 80% duty cycle. You really don't want to exceed 80% duty cycle. So if your engine is not making at least 304H.P (flywheel) and you have installed 24LB injectors you are just wasting your money. It sounds to me like your running WAY too rich. You better get your computer or chip recalibrated for the larger MAF and 24LB injectors or you can wash your cylinders and destroy your CATS. I installed 24LB'ers about 2.5 years ago and had to get my SUPERHIP recalibrated for them via MIKE TROYER. My problems was I was making a lot more H.P than my stock 19LB injectors could handle and it was causing a fuel starvation problem above 4500RPM at WOT. I also added a WALBRO 190LPH in tank fuel pump and a AEROMOTIVE adjustable fuel pressure regulator. Now my fuel starvation problem is gone and my 5.4 pulls HARD up to, and past 5400rpm.

 

i would talk to who you bought the stuff from. are you sure the maf sensor is calibrated for 24#? if the maf is setup correct it should run as smooth and good as it did with the stock 19#.
maybe put the sock sensor on and see if it runs the same.

 

MAF would be the first place to start, it needs to be calibrated for the larger injectors. Chip would also need to be calibrated.

I second Neal, why the switch? The only time you need to jump up to 24# or 30# injectors is if you are running a turbo or a supercharger.

 

i might be wrong but i think having the maf calibrated is enough and it should run fine without a chip.

only reason i would change injectors would be if i had plans for a supercharger(i would skip 24's and go to 30's) or if i had a lot of mods or i needed new injectors and the 24s are a little insurance for future mods.

ever wonder why Ford put 19's on a 260 hp 5.4, but up-graded to 24's on the first lightnings and the 93 cobra that where both rated at lower h.p. than the current 5.4?