Fuel Injectors

-Alero- · 03-28-2005, 03:46 AM

hey i noticed in the alero upgrade section, there is no longer a link for 3400 aftermarket fuel injectors. where can i get aftermarket fuel injectors for my N/A alero? also do you guys recommend upgrading the injectors? or should i leave em stock?

BlackJack · 03-28-2005, 04:04 AM

heard someone mention using injectors from an Envoy (GMC suv)

-Alero- · 03-28-2005, 04:06 AM

i think it was S/C or one of those supercharged feller's that had trailblazer injectors or something.

03-28-2005, 10:42 AM

yes any of the trailblazer bravada or envoy will work.

if you should do it depends on what mods you have done. if you feel that you are running out of fuel then by all means do it. if i am not mistaking the factory ones are 22# and the envoys are 28# someone correct me if i am wrong i can't honestly remember what they are i have been running them for so long now

03-28-2005, 11:14 AM

unless your boosted via a REAL turbo or supercharger, you should not need to change your injectors, ever.

and if you do decide to do it anyway, you will need to have your PCM reprogrammed for them in order to run/idle correctly.

03-28-2005, 12:03 PM

^^^ i disagree i never had to have mine reprogramed and there are a lot of people who did not need it either. i got the injectors when i was running n2o and never had a problem

03-28-2005, 01:17 PM

i said to idle and run correctly

i had 22# injectors running my car and it was programmed for 19#.

it ran and drive fine, fuel consumption was lousy though.

you can make it run with bigger injectors, but tuning it correctly is the only way to do it right.

03-28-2005, 04:23 PM

again i never had a problem. it ran and idled fine never threw a code or anything. seems odd how everything i have done that you advise against or say is bad idea's or what ever the case maybe, has not been an issue. i respect everyones opion i really do but you seem to have something to say against everything that i have done, want to do. just an observation. this thread is not for a battle. just seemed kind of odd that is all

03-28-2005, 04:41 PM

first of all i am not trying to do anything either, just stating what i have found and what i have observed.

what you gotta understand about OBD2 systems and fuel injectors is that the PCM is programed for the size of the injector. if you place a larger injector into your engine and not change the value in the pcm your going to run rich. point blank. that is proven. you may not notice a driveabilty issue or throw a code or whatever, it really depends on how much larger you go.

for example....

stock is 22# injectors. so you slap some 26# injectors in. your pcm is set up to open the injector for a certain amount of time (m/Sec).

the 22# value is about 380 mSec/gram. so now you put in a 26# injector and keep it open for 380 mSec your going to dump in a LOT more fuel that 1 gram. why you ask? because the 26# injector flows more. its simple to figure out really since each injector is rated at ~43.5psi. what this does is just dumps more fuel in. your car will run rich and the PCM will "sense" that this is happening and back off some of your other parimeters to control the fuel. by doing this it will cause your Short Term Fuel Trims and your Long Term Fuel Trims to be WAY OFF. and when your STFT's and LTFT's are way off (rich), then you will have excessive fuel consumption.

basically its simple math. and no matter what you did, your buddy did, the guy down the street did, or some other guy did on the internet, the #'s wont change and the values are constant and the conclusion is the same.

03-28-2005, 04:45 PM

well this i agree with it does dump more fuel. i thought this was the whole idea of the thread was to add more fuel. or am i missing something. i just don't know anymore

03-28-2005, 04:55 PM

lol, yea, the thread is about adding more fuel... but when you put in bigger injectors, to make it run RIGHT, you have to reprogram the PCM to accept the larger injectors so you have CONTROLLED fueling and not just dumping it in.

if you REALLY want more fuel and your N/A, i would recommend getting an adjustable fuel pressure regulator. that will add more fuel with higher fuel pressure and only do it when you need it (top of the rpm band).

again, i will say this, if your N/A and have no plans on getting a turbo or supercharger then you should not have any reason to get bigger injectors for a 3400 engine. your not ever going to get enough power from your N/A setup to ever run your stock injectors into a static situation.

-Alero- · 03-28-2005, 07:25 PM

hmmm, why i never

SilverBullet256 · 03-30-2005, 12:57 AM

is it just me or are germ and sc/alero kinda like adversaries of boost, both with the power of boost but each one from a different side, one from super and one from turbo, the light and dark side shall i say

03-30-2005, 09:04 AM

lol

its always good to have more people chiming in.

when people only get one side of the spectrum, they tend to downgrade the other end and never had any info/experience with it.

03-30-2005, 10:00 AM

Quote:

Originally posted by SilverBullet256@Mar 29 2005, 09:57 PM
is it just me or are germ and sc/alero kinda like adversaries of boost, both with the power of boost but each one from a different side, one from super and one from turbo, the light and dark side shall i say

Quoted post

yeah i think that is a safe statement. i am sure if springs was on the board more he would have a lot to say as well. bt i agree with germ the more you know the better off you are going to be. damn i sound like a comercial now