big injectors?

[96awd16g]

Is it possible for the stock ecu without any sort of tuning to run bigger injectors? I bought my dsm about a month ago and it has been very rich.

Its got all new plugs and wires (bpr7es) , etc. I have a narrow band afr gauge and have been reading plugs and slowly leaned out the MAS screw to flush with the housing and its still extremely rich.

I can get a best of about 21 mpg driving very easy and problem seems to be worst below 4500-5000 rpm and then it cleans up fairly well. Fuel pump is not yet rewired, but in the works (have been waiting since i already have too much fuel). Boost has been 14-16 and im still very rich at 16 psi.

What do ya guys think? bigger fuel pump? injectors? or should I look somewhere else?

ALSO I scanned for obd-2 codes and came up with no downstream 02, etc, as well as what I believe was a p0170. Code wasnt listed in vfaq, so I did a basic goggle search and came up with, "It also indicates that the fuel trims reached their limit of adding fuel while trying to compensate for a actual or perceived rich condition. When the fuel trims reach their rich correction limit, the PCM (Powertrain Control Module) sets a P0170, indicating a problem or malfunction in the fuel trims."

 

[92AWDHX40]

if your running bigger injectors you will need a way to tune for the extra fuel.

 

[dral24]

yeah what he said nd if the only gain u want is to run larger injectors get a maft with the gm maf

 

[96awd16g]

But it is possible for it to run the bigger injectors as is? I was questioning whether it would run at all with larger injectors and how to identify what they are if they arent stock. Anyone have pics of stock injectors? or know color? or are they all black?

 

[Sam@RRE]

Wow...a lot of wrong info here. If your car is running rich already, why would you think bigger injectors will fix that? That just adds more fuel. GM mafs and MAF-T just plain ol suck. The only thing they ever had going for them is that you can run it blow through and vent your BOV. Other than that it sucks.

Get a logger and log your front o2 sensor. The sensor could be dead and stuck at low voltage, and the ecu think the car is running lean. Thus adds more fuel till the trims are maxed out and throws the P0170 code and your car is left burning fuel uselessly and with a CEL on. Dont start adding parts, its the single worst thing you can do that will put you in an endless fubared loop of chasing your tail.

Stock 2G injectors are black, the have 450 molded into the sides of em.

If the car had bigger injectors in it, it would barely run and stall everywhere.

 

[jrohner]

Many things could make it run rich, including running larger than stock injectors with no way to compensate for them.

Wow...a lot of wrong info here. If your car is running rich already, why would you think bigger injectors will fix that? That just adds more fuel.

He thinks he already has larger than stock injectors, not that he should get them.

But it is possible for it to run the bigger injectors as is? I was questioning whether it would run at all with larger injectors and how to identify what they are if they arent stock. Anyone have pics of stock injectors? or know color? or are they all black?

2g injectors are black. The pintle caps are usually green and have two holes in them, which you can see if you pull out the injectors. Get the numbers off the injectors or post pics of them (pulled out of the car).

 

[dral24]

well if they r stock dsm injectors they usually say the cc size on the side i.e. black top turbo inkectors should say 450 on them, but there r blue top 450's as well..
evo injectors come yellow nd r 560 i believe but also come with pink tops,
tricky thing is n/a 1g also come with pink tops nd r 240cc i think, nd n/a 3000gts r pink top 245's

as for your question no u cant run bigger injectors with stock u u have to run a piggyback program to trick the ecu..

injectors:
pink - 240cc - 1g n/t 2.0L
blue - 275cc - some mirages
not sure on color - 310cc - 1g n/t (94 se cars)
white/tan/light grey - 390cc
blue - 450cc - 1g turbo/galant vr4
black - 450cc - 2g turbo
yellow - 510cc - jdm galant rs (not vr4)
salmon pink - 560cc - evo 8,9

now do not quote me but this is the info i've gathered
here is what to look for this is a black top 450 if u look it says MDL450

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[96awd16g]

Yes correct I believe it had larger injectors when I bought the car.

I will try to pull the injector later this evening or tomorrow morning. A larger fuel pump in no way could cause it to be excessively rich? It simply flows more as the demand goes up, doesnt constantly flow more, correct?

Thanks that helps termendously!

Also when I first got the car it did occasionally stall and always idle dropped way low before coming back to 750-800 rpm, black soot even on the outer rim of the exhaust tip, plugs have been black as can be and ran substantially better with new plugs (bpr7es vs. bpr8es) and wires. Car didnt begin to idle fairly well til I backed the MAS screw out flush and have messed with the BISS

 

[dral24]

thats correct

 

[96awd16g]

Well no news on the injector tonight. Got distracted putting it on a diet and removing spoiler (love it btw!). But no work for me tomorrow so will be pulling injector tomorrow as well as doing a few other little things.

How much boost (16g, believed to be small) can I safely run on a stock rewired fuel pump with stock or 550cc injectors? I typically run 92 gas, on rare occasion 91. Would I be able to tell if fuel pump has been replaced/upgraded by just pulling it out of the tank?

 

[dsmkight]

try an aem WIDEBAND that will let u know your a/f ratio more accurately

 

[TSi Kid]

Safe? 14 lbs

What're you able to run before fuel cut? 17-19ish

 

[96awd16g]

Thanks, I've been trying to keep it around 14-15 psi but with how rich its been i've played some and already seen fuel cut around 17 psi. I just don't want to be doing that all the time til I know what's going on here.

Agreed, I most definitely need a wideband, but it's in the works. : thumb:

 

[artymillz]

I'm currently running 550s in my 97 gst with a stock ecu and the car runs fairly well....my main problem is my greddy type RS blowing into the atmosphere