what would cause small intermitent puffs of black smoke at WOT.

 

Youve got 4 trucks listed - which one are you talkking about?

 

the 97 model 12 valve

 

Well, youve got a 100 plate slid all the way forward and the AFC housing slid too - that could have something to do with the smoke, dont ya think?

 

Hey now, there's no need for sarcasity (sarcastity, sarcasticness?)


Just a guess, since you're undervalved , you're hitting the wastegate.
It opens to let off excess boost and suddenly you don't have the air to cool the fire so you get a puff of smoke, then once the excess is bled off, the wastegate closes and puts the fire out till the next time the wastegate opens.
This happens very fast, so it looks like puffs.


phox

 

yea i thought it might but i posted a post earlier today that i have reajusted the afc and starwheel i need to update my sig still getting used to this new look,but anyway i didn't get any replies to that post. after reajusting everything my boost comes on hard and strong at 2200rpm it used to come on at 1600 to 1800rpm, i like the way it pulls now but i developed this intermitent puff of smoke?

 

phox mudler that might explain it because before i reajusted everything i had the wastgate disabled and it wasn,t doing it thanks.

 

No sarcasm here - didnt mean it that way !

Im quite suprised there wasnt a puff of smoke before plow adjusted the AFC and starwheel.

 

The puffs may be dependant on your boost level.. If you are just at the 35 psi mark (or about that) then the gate will pulse open and closed as the drive pressure in the exhaust manifold will also fluctuate which will pulse the gate.

I don't get puffs, but you do see the gate open. There is a good blast of smoke from the start then it greys out to a mist and then starts to darken up as the RPM rises and the boost tops out at 35 psi. Then the smoke starts to get darker until the stock governor backs out the fuel.

Short puffs may indicate a sticky injector. I had that happen on my 89 waaay back. One injector was hanging up and would cause puffs enough to fill a 5 gallon pail intermittantly under full throttle.