6SOARER

iTrader: (20)

Some of you may know that I've been having stuttering issues with my 1.5 build. I been struggling to diagnose the problem and need some help. The CEL isnt ON but I wanted to see if the computer was storing any codes. I pulled a code25, system to LEAN. So this explains why my car is running like crap.

You 1.5JZ guys, are you using your stock injectors?

Since the 1.5 uses a slightly larger displacement block, wouldnt we have to compensate more fuel for the additional air?

Im stuck and have a feeling that my fuel system is at fault. I dont wanna drop money that I dont have and start throwing parts that are not going to fix my problem.


I want to run a fuel pressure test to see if it I got sufficient pressure, where would I tap into?

Are the GE injectors larger than the 1JZs? I was going to test out the GE injectors to see if it helps my LEAN condition.

Superjatt

iTrader: (1)

I have injectors if you wana test them out. shoot me a text bro

RyanV

iTrader: (9)

Do you have a wideband installed to see when it's going lean or if it's all the time?


1JZ=370cc
2jzge=315cc

6SOARER

iTrader: (20)

I dont have one hooked up yet.

I ran it on the dynomameter which puts a load on the car and took a sample of the exhaust with the 5 gas analyer. My CO2 readings were 11.2%(14.7 is ideal-stoichemetric) and my O2 levels measured 3.5-3.7%.

Guess the GE injectors arent going to work. Im gonna need those 440s AJ when I get that intake manifold off.

Biggu

iTrader: (12)

When was the last time you changed out your spark plugs?

6SOARER

iTrader: (20)

I replaced them last month with some fresh NGKs(that everyone is using on the 1Js) gapped at .028. I threw some heat shrink tube over the boots on the coils also but it didnt help

Superjatt

iTrader: (1)

At which RPMS does this happen btw?

6SOARER

iTrader: (20)

As soon as I gun it, full throttle. It can occur at 2500 to high rpm.

I really think its a fuel issue. You know I cant remember what fuel dampner Im running, the GE or the 1JZ, I wonder if running a GE dampner can be my problem?


The 1JZ dampner did not bolt on to the block cause the GE block is a little taller than the 1JZ. Im going to try swapping those out before I hit you up for those 440s.

Superjatt

iTrader: (1)

I saw a thread somewhere were the guy didnt even have to take out the manifold to get to the injectors, he just used a flathead to take em out. YOUR choice mang if you need em i got em

Yahoo27

Are you running a safc?? I'm pretty sure your gonna have to start adding fuel with the 3.0 block because it's bigger.

I have 550cc injectors on my 1jz I had to pull alot of fuel, then when I went 1.5jz I had to pull less fuel, so the 3 liter does make a big difference

6SOARER

iTrader: (20)

Im not running a SAFC.

The car runs great when its COLD, in open loop. But that last too long cause when it warms up the problem occur

6SOARER

iTrader: (20)

can a GE dampner cause my stuttering issues?

Ali SC3

iTrader: (10)

if it is running fine the rest of the time i dont see why a ge damper would have any affect. I hit boost just fine with the ge damper and ge fuel rail on my na-t. sounds like you need some 440s or 550s and a wideband. every turbo car should have one. seriously.

Luv2xl

iTrader: (5)

are you running a fine tune instrument such as a AFC? If so, try adding fuel see what happens.

Yahoo27

I've read somewhere and experienced it with my car is that when you first start the car it will run rich until it reaches it's normal operating temperature. So for your problem when it first starts the stock injectors are putting in more fuel than at normal idle, which puts your afr at a better AFR than when it's warmed up, so it will run better until the car is warmed up. You should really get bigger injectors or an safc and add some fuel in there or even both :P