"Decel" function on MT LTX8
 

Scenario:

Car smokes (bluish smoke = rich) on deceleration.

Question:

The "decel" function is currently set at 25. Would decreasing to 19-15 help or advisable? Could there be a vac leak somewhere? Perhaps the injectors are dirty or going south?

Also, NOTHING has changed on the car. I started noticing the smoke the last couple of weeks.

Thoughts?

Thanks in advance.

I always thought blue smoke == oil being burnt


What does it smell like? Does the exhaust smell really bad of raw fuel?

If it is oil:

Does it smoke more when you run it up a gear? if so.. may be oil control rings. could be turbo as well.. did you use a restricter pill on your turbo's oil inlet?

blueish=oil.... so either look at your turbo or your motor... A good hint would be to smeel the oil...

Btw, when you are on decel, what vac #'s do you see??? Im guessing over 23" ?? right?

It smells like fuel. It does not smoke when you're on the pedal, only on deceleration. I can run and gun it with no smoke. It seems like the car still dumps fuel after you let off the gas. The smoke goes away after about 5-10 seconds.

Yes...25"

I don't smell oil, its more fuel.

How old are the injectors? What fuel pressure are you running? If you have a 1:1 regulator how much boost?

No, I meant the oil... See if it smells like gas... If it is, then it prolly diluted the oil and might be passing through your oil seals or turbo seals..

Got it!

Now if the above is the case, wouldn't the car be smoking whether your on load or decelerating or idle?

Thanks !

Are you on the stock turbo ???

No.

13bre, T66 - q-trim- .84a/r, premix 100:1,

I'm looking at the possibility of fouled plugs. Will replace and provide update. Also a wiring check for the 50th time.

Checked the turbo and the ic pipes, no oil whatsoever. Engine oil has no scent of gas. Checked all vacuum hoses - everything is connected well. Compression checked out fine.

TIA

^^^^

How did I miss this post...anyway.

The injectors are 1.5 yrs old (550pris and 1600secs). Fuel pressure is about 40 normal and 57-60 on boost (20psi).

After the plugs, I'm taking out the injectors for inspection.

Thanks!

Well the only odd thing about it being fuel is that if it was dumping in a large amount of fuel, i would expect the oil to smell like fuel as well.

Still worth it to look at the injectors though. If this started without you making any changes i would not make changes to your EMS.. Unless its possible you just didnt notice it before?

It could be that you used too much premix.... I dont see a problem with a lil smoke while on premix.... BTW, why would you check wiring ?? If the car runs, then its definately not a wiring problem...

It has been running flawlessly for months until a couple of weeks ago. I've been on premix for 2 yrs now using the 100:1 ratio with no issues. I don't think this is the case.

What is the recommended oil/fuel mixture?

Something may have come loose on the wiring over time. Plug leads, bad wiring or a faulty CAS could send a bad signal and potentialy pulse the injectors twice as normal.