I have been noticing that when im into the pedal pretty good and looking into the side mirror watching the exhaust i will have a thin trail of smoke and all of a sudden a big black puff will come out of the exhaust. I have a hot tune from dp tuner and i understand that black smoke is expected under hard acceleration but thought it was odd to see a big black puff sometimes. almost seems like it may be coming from one cylinder but its not consistent. what do you guys think? is this a bad sign?

 

Put it on the hottest tune you have, get out on a stretch and let it rip for a bit. Say 0-60 Hard into it.

I don't run a heavy tune but it does load up because I drive it comfortably let's say

I don't switch tunes unless it's a passing situation, but when I'm on it, the USAF sends out the water cannon aircraft.

Complete stock with nothing aftermarket except for the TS chip and my wife, (so help me god........


Might just be buildup?!

Denny

 

Is the black puff in all tunes or just the "DP hot tune"?

Is the black puff when the transmission is shifting up, or just randomly?

Any other pattern or signifying marker of the black puff of smoke other than when you are into the fuel pedal hard?

 

I always have it in 80 up tow tune since I tow everyday. I am pretty sure that it does it in 80 horsepower daily also. The Puffs are random and I don't believe it is when it's shifting. Usually when I'm in third gear and in about 3/4 throttle. Nothing significant to say when it happens though. Sometimes it will be just one big Puff and sometimes it will do it 2 or 3 times in a row. Is that a sign of unburnt fuel in one cylinder Maybe? Is this a sign of a cylinder going bad? I only have 170,000 on it.

 

What exhaust do you have?
Do you let it idle for extended periods?
I have seen this happen in diesels that idle a lot. Soot builds up on the walls of the exhaust system and in the muffler. When the engine starts pulling or working hard, chunks of the soot become dislodged and break up as they pass down the exhaust pipe until they exit as a puff of black.
I'm not sure that this is your problem, but it is a possibility.

 

i have a stock exhaust, and i do have to let it idle alot. i am constantly on the phone for buisness, so i have to sit in the truck to get away from all the chainsaws and heavy equipment noise. you might be onto something here hd rider.