Hey all,

I installed 370cc injectors the other night, per what many people have chosen to do after their stock injectors crapped out. The RC's were the cheaper alternative to the stock replacements. I thought that the extra 10cc of flow wouldnt make a big difference, given i hadnt read anything negative about going slightly bigger.

Now that they're installed, the car has developed a stutter under low-rpm, part throttle conditions. The code is for Rich Fuel Condition, or something to that effect.

Is there anything I can do to resolve the problem while keeping these injectors? Are the injectors even the problem, or is it something else that as manifested itself at a purely coincidental time? Perhaps I need a tune or a chip or something?

Any help would be greatly appreciated!
Thanks

DCs2

 

FYI - its an 02 with 87k miles

 

I don't think you're suppose to modify the injectors without a tune. Larger injectors are less consistent with what they inject at low throttle / idle conditions. Imagine using a fire hose to fill beer cups.

 

Yep, your suppost to have something that can control your fuel when you upgrade your injectors. People upgrade their fuel system when they are pushing more air into their motors (i.e. turbo, supercharger, nitrous). So they dont run lean. On a stock motor with the same intake its taking less air, and putting more fuel than needed. So of course you will run rich. Either get it tuned for those injectors, or get some OEM injectors.

 

Did you at least reset your ECU? The ecu might be able to handle the 370cc injectors but it is going to need to readjust the fuel trims and relearn for sure.

I run 390cc injectors in my 3000GT which comes stock with 360s as well and it's doing just fine, however the 3000GT ecu may have more wiggle room with the fuel trims.

 

To get it tuned, would I need a VAFC or something like that? What are my options?

 

im pretty sure to get it tuned you need a new ecu dont quote me but i heard only the 06 and up are tunable with stock ecu. someone tell me if im wrong lol

 

^ No sir, you can tune with an ap1 ecu. With something like a VAFC you have to get it WOT tuned because the ECU will erase all your settings if its at partial throttle tuning. WOT tuning will not be erased. 06+ ECU's can be reflashed since it doesnt have a permanent memory, so its easy to get a reflash like that.

 

ugh i want to punch myself for not spending another 70 bucks and just getting OEM ones.

 

ah i see thanks suzuka-blue-s2k.

Well DCs2ooo have you tried adjusting the idle on the throttle body? it probably wont solve the problem but it seems worth fussing with before spending any more money