If i put 42.5 lbs. stage 1 gm injectors in my stock car will it be that out of control without a tune? I'm going to tune when I have more money exhaust and a smaller pulley size. Sorry this is a noob question. Will gm throw their tune on it if they didn't install the injectors?

 

don't install the injectors with out a tune

 

You can install the injectors without a tune and it'll drive fine, however once you go full throttle it will dump fuel like crazy. I only recommend doing so just to get it to a tuner from your garage. It's best to do it all at once.

 

I would not drive the car in boost, or above like 30% throttle with those injectors without a tune man. I HIGHLY recommend getting a custom tune before you flood your motor.

 

i just always tell people not to do it...cuz most of the time they will say "oh its running fine...lets race" seen it happen, heard of it happening...no need for more to do it

i knew a kid that put 60's and a 2.7 on with no tune and drove 50 miles to a tuner like that...we all(06black, myself and others local) told him not to do it...but he did

he got to us fine, but damn people just dont listen

 

While cruising and in stoich everything is fine. But get into boost/pe/wot is where you get into trouble and really screw things up. I 99.99% always tell people not to do it unless they are literally just driving down the block/street and I always recommend to baby the **** out of it. I will NEVER let one of my clients drive to me though without a tune if they are using new injectors, hence why I travel to them =D.

 

I usually install the injectors and what ever other parts said individual wants in my garage and then tune them for it. Like I said I don't recommend it, but it will work fine to get to a tuner as long as you do not cross into boost. I did this for my GM Stage 2 way back when. Got the parts and installed them, and then drove the stealership the next day for the tune.

 

As everyone else said, its ok for a short time if you dont give it much gas. I know a guy who put 60's and a 2.4 (yes 2.4) on and ran the stock tune. He beat that car with no cooling mods and no tunefor like 2 months and never blew up. I have no idea in the world how that thing stayed running but it did. But I would never beat on it without a tune, he was just dumb. And his car was really slow and sounded horrible when he went WOT

 

under vacuum (bellow 100kpa) the pcm will use the 02 sensor to read the crosscounts and figure out if the car is rich or lean, and based on that it adjusts the fuel trims (long term fuel trim) to suit. the car will drive ok for a short time till the fuel trims get over -18% (means its rich, -18% means its trying to take away 18% fuel from the programmed tables) and then itll set a p0172, fuel system rich code. the car may have a couple hiccups and drive a tad funny, but it will get you were you need to be.

now under boost (above 100kpa) the pcm does not use the 02 sensor for fuel calculations, its directly off the programmed tables. the car will run very rich, sputter, smoke, ect. if run too long like this you will wash the cylenders out and unseat the rings, have excess carbon build up, foul spark plugs, ect.

my recomendation, dont do it. i wouldnt even change the injectors and drive it to a tuning shop, i would do it on the spot.

 

Ok thanks for all the help. 2K5SS/SC? the dealership threw their tune on the car. How much did that run you I am talking to my local dealer and seeing if they will do that for me but I won't know until monday.

 

I bought the GM Stage 2 kit from the stealership, installed it myself, and then they verified the installation and flashed the tune in. Probably the only good thing they did for me as a matter of a fact.

 

Oh ok well I bought some gm injectors from a guy on here you think if I gave them a little cash they would do the same for me?

 

they can't flash it on for you unless you have the code that comes with the kit.

 

if you want. i can put a gm stage tune on the car.

 

That would be cool area shoot me a pm with your price I have talked to you about the price of your custom tunes but Im not quite ready for that yet

 

gm base tunes are free. they didn't require any brain power on my end to make