Questions about fuel Injectors

[black_demon69]

If the 4.0l has 19lbs Injectors would it increase horse power to install 24lbs Injectors?

 

[ericbphoto]

I doubt it. The ECU fires an injector for a calculated period of time. With a bigger injector, at the same fuel pressure, the injector doesn't need to be open as long to give the proper amount of fuel. So the ECU is supposed to figure that out and adjust the "open time" usually called duty cycle. If the injector size is too far out of range, then the ECU won't be able to correct and your fuel ratios will be wrong. In other words, don't do it unless you understand all the ramifications and have tools and skill to retune it to work properly.

 

[PetroleumJunkie412]

Ericbphoto is correct.

Increasing injector size without tuning will likely make your engine not run, or run like sh*t.

I run 24lb injectors on my 2.9, but I also have an aftermarket ECU. Injector changes for most tuning systems are 3-4 keystrokes. My ECU is set up to change the fuel map to match the volume of fuel my injectors can flow

If you do want a crisper throttle response, you can go to multiple hole injectors. May not do much for power, though. Then again, it may. Ymmv.

Looking for easy ways to get a little more oomph out of the 4.slow? (serious question, not sarcasm ??)





@ericbphoto: I really hate being "that guy", but injector opening time is pulsewidth. Duty cycle is a percentage of how much fuel an injector can flow. So at a given pulsewidth of X, an injector is at Y% of its duty cycle. Sorry if I'm coming off as a dick.

 

[ericbphoto]

@ericbphoto: I really hate being "that guy", but injector opening time is pulsewidth. Duty cycle is a percentage of how much fuel an injector can flow. So at a given pulsewidth of X, an injector is at Y% of its duty cycle. Sorry if I'm coming off as a dick.

No problem. I know enough to give some advice and to know that I don't know it all. I have some friends in drag racing and I am learning a lot from them. But I haven't built an engine with stand-alone ECU yet. I have just enough knowledge to get started and to figure out what else I still need to learn. I may have gotten a term wrong. But I was in the ballpark with helping him figure out it's not "that easy".

 

[PetroleumJunkie412]

No problem. I know enough to give some advice and to know that I don't know it all. I have some friends in drag racing and I am learning a lot from them. But I haven't built an engine with stand-alone ECU yet. I have just enough knowledge to get started and to figure out what else I still need to learn. I may have gotten a term wrong. But I was in the ballpark with helping him figure out it's not "that easy".

Don't kid yourself, you know a hell of a lot more than you think ??

Standalone ECU is crazy easy. If I can do it, anyone can.

 

[black_demon69]

Thanks for the responses you all have confirmed what I was thinking. I am looking to replace Injectors because I have 3 that have gone bad somehow during the rebuild. (they worked fine prior to tear down)

Due to money will probably just replace the 3 and clean the 3 working ones. (I know they should be replaced all @ the same time)

 

[black_demon69]

1994 FORD RANGER Accel 150619 ACCEL Fuel Injectors | Summit Racing

Free Shipping - ACCEL Fuel Injectors with qualifying orders of $109. Shop Fuel Injectors at Summit Racing.

www.summitracing.com

What do you think about those

 

[Lance Morgan]

Ericbphoto is correct.

Increasing injector size without tuning will likely make your engine not run, or run like sh*t.

I run 24lb injectors on my 2.9, but I also have an aftermarket ECU. Injector changes for most tuning systems are 3-4 keystrokes. My ECU is set up to change the fuel map to match the volume of fuel my injectors can flow

If you do want a crisper throttle response, you can go to multiple hole injectors. May not do much for power, though. Then again, it may. Ymmv.

Looking for easy ways to get a little more oomph out of the 4.slow? (serious question, not sarcasm ??)





@ericbphoto: I really hate being "that guy", but injector opening time is pulsewidth. Duty cycle is a percentage of how much fuel an injector can flow. So at a given pulsewidth of X, an injector is at Y% of its duty cycle. Sorry if I'm coming off as a dick.

I put v10 injecters in my stock 2.5 it helped it a lot low end and mid throttle responce

 

[Lance Morgan]

Iv addeded a turbo and intercooler and haven't programmed stock computer so my question is what are you guys using to rewrite maps and what are you using to program the computer cause I absolutely have to change the maps to get this girl to run right

 

[Lance Morgan]

Anybody know what size injecters are in a 460

 

[rusty ol ranger]

Anybody know what size injecters are in a 460

24lb/hr.

Stuffing heavier fuel injectors in a stock engine is more less like the guy bolting a 750 double pumper on a stock 302, minus the flooding.

Now, if you up the amount of air coming in by a large margin (by forced induction, etc) then heavier injectors will help assuming the ECM is reading all that extra airflow