I have a 1990 f150 with a stock fuel pump could I use 21 pound injectors??

 

I believe you can.

 

How is your motor modded? If stock, is there any reason to upsize? I don't thing it'll gain you anything, but could be wrong.

 

Yess its a stock motor..it has headers but that's about it. I just have a feeling that my injectors are gummed up n possibly bad.I just wanted to by sum brand new fresh injectors so I know that they are new and in good shape.I was just wondering.I'm not trying to gain any kind of power.just better response maybe

 

What's wrong with fresh stock 19's? The 21's won't do a thing for you with a stock motor.

Before replacing them, run some Techron through the fuel. That may clean them up.

 

Difference is 2lbs

 

Hey, no one likes a smart ***..

 

So can I run them with a stock pump???will it pump hard enough?and what should the pressure be regulated on the rail?right now its at 30.

 

I've heard you can , but I'm not sold on it, not unless you re-map. Just guessing, but when you increase the injector size, - seems that you need to increase the pulse width setting in the PCM (for correct pulsewidth\duty cycle). I could be wrong, maybe the PCM can re-map, to a certain point. Like, it may be okay up too 90% throttle, but you could lean out wide open.

Other than that, -a tuner could dial in that much of a jump. You won't gain anything.

 

Dang Pat beat me to it. LOL

Dumping more fuel isn't going to make it run rich? Or is that not enough increase to cause the computer to not be able to correct for it?

 

:d ___

 

:d

.........

 

Just buy a new set of 19#ers and take all the guise work out of it!

 

Would it hurt to put 21#rs in???would anyting not function correctly besides maybe my computer??

 

If your computer isn't right, then your truck won't run right.