I have been reading a lot about the fuel injectors, but I still have some questions. What is the stock size for a 1999 F-150 5.4? Also, when should I upgrade? Right now I have a FIPK from K&N, Gibson dual exhaust and 75mm throttle body. I want to to the troyer performance reprogrammer and the 90mm Lightning MAF. Should I upgrade my injectors. Thanks for the help.

 

HI!... The stock injectors in the 4.6/5.4 are 19LBS (orange body). They will support up to 304H.P (flywheel) at 90% duty cycle. A 24LB injector (light blue body) will support 384H.P (flywheel). Your current mods do not require you to upgrade to larger injectors.

 

Thank you for your help. If I ever want to upgrade, don't I have to have the reprogrammer programmed for larger injectors? Thanks again

 

If you change your injector size or use a 90mm lightning maf, you'll need a custom tune unless you went with a Pro-M maf that can be calibrated for the right injector size when you order it. I don't see any need with your mods.

 

should i have to change injectors. i have 98 ford f150 4x2 with k&n injection kit, bbk throttle body, helix power tower spacer, gms mass air flow sensor, pacesetter headers and performance exhaust. hypertech power programer and electirc fans. would it make a difference if i changed those?? thanks for the input

 

HI!... 4.6 or 5.4?????

 

Neal

what about #30 (red). i have them in my stang with aprox 350hp at the flywheel and then a 150 shot of Nos in a wet system.
Are they ok or should i go bigger?

 

i have the 4.6.

 

Listen the NEAL he has it right.
The injector size is based on hp production.
You would have to do mods that increase hp dramatcly before larger injectors are needed.
The only way that happenes is with a blower for outside (the engine) changes to the motor.

 

my mpg & power went down after I put in 19lb SVO injectors.