I have "visual smoke on snap idle test"

[BrianWalker]

I think this a problem. The engine is stock. 111k miles. I did pass the smog check (the OBD recall was performed by the dealer before the smog check).



Performing the throttle snap and seeing smoke, my guess is injectors.

Smoke means fuel(power) or excess fuel from what I've read about here and should not be there if I don't run a "fueling box".

On acceleration from a stop it also acts like it has a "flat spot", then goes and has a puff of black smoke. Almost like a flat spot from a dirty or malfunctioning carburator.



Any ideas?

 

[thomasrmmr]

hi; normally , if i blip the throttle to the floor quickly it does and has always thrown a slight black puff ; i beleave the turbo hasnt caught to the fuel , thats all normal unless blue smoke oil white smoke foiled injector - raw fuel or compression problem ,

 

[thomasrmmr]

oh mine is an 2006 hpcr motor w/ 84500 miles stock great power too,

 

[JJPage]

When you do the snap test, roll into the throttle instead slamming it down, they will never know the difference. As long as you hit 2800 rpm or above you should be ok.



The first time I did the opacity test, I failed, the second time, I almost failed because I placed a block of wood under the carpet beneath the accellerator pedal..... not sure what I was thinking... but the truck barely made 2800rpm and they said they could not obtain a sufficient reading at that rpm.



I did pass with a 39% opacity reading, 40% is max and still pass is WA.

 

[JDiehl]

Get a smarty and load the half power software.

 

[Bob4x4]

What I have noticed on the 3rd gens... ... ... the trucks that are driven for fuel mileage(too easy) will tend to smoke more when the throttle is hit hard occaisoinally. I am thinking it is just the soot built up in the pipes being blown out. Drive it harder for a while and I am going to guess it will clean up some.

 

[Regcabguy]

I probably fit in that catagory. Due to nagging smoke on the '07 with my Smarty,I removed it. The first dozen or so times I laid into the throttle hard,tons of black smoke came out. Since then,a 450 mile freeway trip and more extreme throttle application has apparently cleaned out the soot built up in the cat and muffler. Maybe the slightly elevated egt's are helping also. I miss the enhanced driveability,but now the exhaust is clean. My air filter is new with the psm cai,so restricted airflow is not an issue.

 

[BrianWalker]

Thanks for the ideas.

I'll be glad to put the hammer down more often and see what happens.

Even at $3. 20/gal, it's cheaper than buying a Prius at $25k when the truck is paid off.



Brian