H.O. fuel injectors...Does any non-OEM fuel injector put out 21lbs at 39 psi?

[Gojeep]

Double post removed.

 

[mustangconv85]

anyone

so can anyone tell me which one of these injectors would work for my 88 cherokee with stock motor http://www.accel-dfi.com/pdf/FuelInjectors_07.pdf thanks

 

[92DripCherokee]

bosch #19 yellow top

 

[JNickel101]

That is what I said when I stated that it is only in closed loop above 175*F. That is the same as saying it is in open loop below 175*F.

I understand what you meant by open/closed...i wasnt debating that...what I was saying is that regardless of your injector type, when you start up, its in open loop, so you'll be "wasting" fuel - I dont understand the need for the adjustable MAP sensor UNLESS you are frequently running below 175* or running at 80%+ throttle. otherwise, it wouldnt be used, right?

EDIT: maybe i'm not understanding - but what i'm reading, no matter what size injectors you have, as long as your jeep is in "closed" loop (using the O2 sensors) and you are under 80% throttle, your ECU will adjust the air/fuel mixture based on the readings it gets from your O2 sensors....

so the only down side to having larger injectors is that during warmup, you'll burn a little more fuel, and if you really get on the gas, it will run rich....

GoJeep, I know you know your stuff....but I dont - so I'm trying to learn

 

[Gojeep]

Yes you have it right now.
During warm up you will use more fuel with larger injectors and over 80% throttle.
Any other time the ECU with make sure you stay at 14.7:1 air to fuel ratio regardless of injector size by altering the time it stays open within limits. So bigger flow injectors would have the injector open a shorter amount of time to deliever the exact same amount of fuel under closed loop conditions than a stock injector.
Now if you have fitted a stroker, like I did recently for someone, I fitted 24 lb injectors as it was too lean under full throttle causing it to ping with stock injectors and raising the engine temperature as well. Even with the 24 lb injectors it was still running too lean at WOT at 14.7 rather than 12.7 that you want at WOT. This is why the ECU is not controlling it above 80% throttle as you want it richer to keep the cylinders cooler and to stop detonation. So I had to build an adjustable MAP sensor to keep the injector open longer to richen up the mixture above 80% throttle.

 

[JNickel101]

So is it even worth it to "upgrade" my injectors? I was just looking for better fuel atomization with a 4 port nozzle....

 

[xL8 APEKSx]

With simple mods, you really don't need a larger injector. It's not like we rev the snot out of these engines anyway, or spend any time at/near redline (at least I don't), which is when you will typically max out the duty cycle of your OE units.

If you just have intake/exhaust type mods, you aren't coming anywhere near max duty cycle on the stock injectors. There's usually enough wiggle room in the OE setup for the ECU to compensate for a few things.

 

[JNickel101]

arrrrggghh....lol...

I know I'm not maxing out the injectors capacity, however...

for better fuel atomization, I would like a 4-port injector vs the stock single port injector....

does one exist for the rating i'd need on my 2000XJ?

 

[xL8 APEKSx]

Check to make sure part numbers didn't supercede to a 4-port injector. On some VW applications (Bosch injectors), the OE units were single-pintle, but those superceded to a more current 4-hole pintle cap.

 

[JNickel101]

Gotcha, thanks!

but there isnt a Ford/Mustang injector that would work for a 2000's specs? I tried looking at 5.0motorsports or whatever...but that site is very poorly built. i get a headache looking at it.

 

[xL8 APEKSx]

I'm sure there's something that would work. I wouldn't sorry too much about operating pressure, as that's easily sidestepped with an adjustable FPR. Just get it in the ballpark. A difference of 10psi is really a minor difference in flow...not like you're gonna go from 210cc to 440cc with a bump of a few PSI of pressure. There's calculators all over the internet, I'm sure you're familiar with them at this point!

Just match low or high impedence, and the style you want. You should be good to go more or less.