Got the car tuned, things seemed fine on the dyno, tuned to 11.5, made 700whp (if you recall the post).

Brought it home, took it out to see if I got the exhaust leak fixed, seems alot better.

Car is running dead nuts lean in boost, rolled into it, hit 13.8 on my wideband.

Of course lifted, threw some fuel at it, in fact about 20% more, seemed to bring it down at the onset of boost, and then shot back into the 12's. Obviously something is up.

Came home, pulled the plugs, and this is what I found.

NGK 8's


Cyl 1.




Cyl 2.


Cyl 3.


Cyl 4.



ID2000's, AEM rail, BAS, 9.6:1 motor.

I know e85 (ethanol) burns differently, and "white is right" according to what I've read, and is different than 93 octane for example. However you can see that 2-4 are soot black from the extra fuel.

So why is their a descrpency across the cylinders.

Did a compression test when I brough the car home from the dyno, and it was +/- 6psi across the board, I'm going to do a leakdown here in a day or 2 when I have a free minute to check everything is still ok.

Thoughts?

 

How confident are you that the exhaust leak is fixed? That's where I would start.

 

How new is your 02 sensor ?

 

Get your injectors checked/cleaned and get the flow rates of each like I did. Then put the highest flowing one on cylinder 4. This probably won't fix your issue but at least you will know that cylinder 4 is getting the most fuel since it runs hottest. Also, I'm not positive, but can't each injector be controlled independently with the AEM? Maybe they are off a bit. Just an idea.

 

X2 I would hook up to your aem to your laptop and see if the afr are reading the same as your wideband gauge.

 

i would get the injectors cleaned and check that might be ur issue...did u have ur car sitting for a long period of time? for example 4-5 weeks or more?

 

I'm not sure how an exhaust leak even if still present would cause one cylinder to differ from the rest, the leak is AFTER the head flange/manifold.

 

Brand new, it's an AEM inline UEGO, installed 2 weeks before I tuned it along with my AEM v2.

 

I'm referring to cyl 1 as closest to you when you open the hood, and 4 would be nearest the firewall. Individual cylinder trim is all zero'd out, I can add fuel per cylender on a % basis, but I wouldn't understand why one injector would be that much off compared to the rest, unless it's clogged or failing.

They were brand new, no dyno or road time.

Where did you send yours to get tested/etc and how much?

 

First thing I did to compare, they are the same. Regardless of that fact, I'm concerned why my plugs are different.