should i get bigger injectors`

[brandonclum]

Ok guys here we go. I have a rebuilt 1g auto with stock 390cc injectors and stock fuel pump i have a 16g turbo installed at stock boost setting so here is the question i fired it up a few weeks ago and wasn't getting spark so did the obvious and changed everything plugs wires ignitor and coils that didn't work so i sent the ecm in that did the trick fixed right no got it back and now it sputters under boost at like 4k could this be caused by lack of fuel on stock boost or does this sound like a boost leak? also i do have a fmic and piping maft setup. thanks in advance for the help guys your the best.

 

[clipto]

I would grab a walbro 255 fuel pump too, but yes those injectors are way to small for a 16g I would look into anything above the stock 450cc injector range for the 16g. Also most will depend on what you have to tune with, if you go ecmlink you can get big injectors and get 1000cc injectors and call it good. Otherwise somewhere from 450cc to whatever will be good for you and will help with the fuel cutout. Just keep the 16g on stock wastegate pressure for now until you get fuel mods.Just missed you had a maft, do you also happen to have a wideband?

 

[cisco818]

Before you buy new injectors u should definately do an air leak test. Its easy and you don't have to spend money.

 

[brandonclum]

On my way to get the stuff for the boost tester now ill let you guys know what the results are.

 

[habitatguy187]

Before you buy new injectors u should definately do an air leak test. Its easy and you don't have to spend money.

On stock boost(11psi) the injectors should be fine. But yes, you should definitely upgrade them when you want to turn the boost up.

 

[MercenaryX2]

What plugs and wires did you put in? And what did you gap the plugs to?

 

[brandonclum]

Ok guys I did the boost leak test and found a few leaks but question im getting bubbles from the idle screw normal??? i'm hearing a leak down by the lower TB also with new gaskets? Also I am running NGK iridiums and ngk regular wires and the gap is at .032

 

[undefined0000]

Grab yourself a cheap M/T computer and 450cc injectors. I ran a M/T computer with 390cc injectors (unknowingly) for the longest time along with a 16g and I wondered why the car ran weird. The only differences are you'll have to turn your idle up a bit because there is only one idle mode rather than 2 on the auto computer and the computer won't pull timing in between shifts, which puts a little more wear on the tranny.

 

[k_maxson907]

I had a similar issue and it turned out to be fuel cut out from boost creep. You could always go ahead and upgrade your fuel system with a walbro 255, larger injectors, and an afpr.

 

[habitatguy187]

Ok guys I did the boost leak test and found a few leaks but question im getting bubbles from the idle screw normal??? i'm hearing a leak down by the lower TB also with new gaskets?

Tiny little bubbles are ok. Check the egr valve for the leak you think you hear.

 

[MercenaryX2]

Wow... no. Fix all your boost leaks. A leak is a leak

 

[brandonclum]

im running a M/T ecm and i do have 450 injectors just not in due to one of them has a busted black nipple boot thing the injector itself is ok just the boot broke not the o ring that it sits in just the black part that sits in the o ring deal into the head. wow that was confusing... but anyway I think the leak is coming from the idle screw and the pcv valve ill get that fixed but can i buy a kit to fix the injector bottom black nipple coat that is broke?

 

[undefined0000]

im running a M/T ecm and i do have 450 injectors just not in due to one of them has a busted black nipple boot thing the injector itself is ok just the boot broke not the o ring that it sits in just the black part that sits in the o ring deal into the head. wow that was confusing... but anyway I think the leak is coming from the idle screw and the pcv valve ill get that fixed but can i buy a kit to fix the injector bottom black nipple coat that is broke?

Is that actually part of the injector or are you referring to a lower injector seal? That's a leak I had for the longest time, I changed em out and my vacuum at 1k idle went from about 13inHg to 17-18inHg.

 

[cisco818]

told ya fix the boost leaks first. its inexpensive and that will take care of your problem. if it keeps up (wich it shouldnt) then change the injectors. but first fix the leaks