LB7: Lots of black smoke in hot weather, almost none in cold?

[whatnot]

What would cause excessive smoke when the weather is hot?
During the winter I have almost no smoke and much better throttle response. Once the outside temperature gets above about 50 it starts to smoke and turbo lag gets bad. As it gets hotter it seems to get worse. (it will pour out black smoke with 28-30 psi of boost)

What would be just a small puff smoke at 32 degrees would completely black out the road if I would let it. I pretty much have to watch the mirror to keep from putting out excessive amounts of smoke (or turn the DSP5 down to a lower tune but then it is really sluggish)

It has Idaho Rob EFI Live tuning and injectors were replaced recently and that made no difference with the smoke.

It has been doing this for years.

 

[LWATSON]

I might would check the MAP sensor or is it referred to MAF? the one in the intake. Do you have an aftermarket air filter?

 

[NC-smokinlmm]

I had Robs tuning on my last truck and it did the exact same thing. I'm pretty sure its tuning related...

 

[THEFERMANATOR]

I might would check the MAP sensor or is it referred to MAF? the one in the intake. Do you have an aftermarket air filter?

2 completely different sensors. MAP is manifold air pressure sensor. It could be used to refer to the atmospheric pressure sensor which tells the ECM elevation, or the turbo boost pressure sensor. MAF is mass air flow sensor and measures the amount of airflow going into the engine. It is mounted in the air intake right behind the airbox.

I had Robs tuning on my last truck and it did the exact same thing. I'm pretty sure its tuning related...

It could be air density. At 32 degrees out you have quite a bit more air molecules crammed into the same space than you do at 80 degrees out. My LB7 with my own tuning runs clean as can be at 50 degrees out, barely hazes at 70 degrees, but at 90 she will belch out a cloud and clean out to a moderate haze when I get on it. I need to get a boost valve because at 22-24 pounds of boost I'm just not getting enough air into the engine to clean it up whereas at 50 degrees at I get enough air mass into the engine to clean up the smoke. Tuning can help with this as you can set it up to not fuel as hard at higher temps.

 

[S Phinney]

It does sound tun I no related but why not log it and communicate with Rob so it gets straightened out for you. I m sure he will fix that problem if it us related to tuning.

 

[56taskforce]

It does sound tun I no related but why not log it and communicate with Rob so it gets straightened out for you. I m sure he will fix that problem if it us related to tuning.

X2 even if it isn't tune related Rob may be able to see something else going on and let you know.

 

[Bryce418]

It's all about air density. It gets especially bad when your at a stop light with the a/c on. The condenser heat soaks the intercooler and the intake air temp sensor (part of the maf sensor) doesn't see that much temp differential. The lbz,lmm and lml have a temp sensor in the y-bridge for that purpose.

 

[PACougar]

I'm guessing this isn't ac heat soak related, he says it starts at 50 degrees. Unless he means Celsius :roflmao:

 

[THEFERMANATOR]

But it can still be heat soak related. As ambients go up, intake air temps into the engine go up exponentionally. Not only is the incoming air into the filter hotter, the intercooler isn't pulling as much heat out since the air going across it is hotter. It could be something in the tuning, but I bet you will find other trucks will do the same thing with others tuning in them.

 

[Bustedknuckles]

What would cause excessive smoke when the weather is hot?
During the winter I have almost no smoke and much better throttle response. Once the outside temperature gets above about 50 it starts to smoke and turbo lag gets bad. As it gets hotter it seems to get worse. (it will pour out black smoke with 28-30 psi of boost)

What would be just a small puff smoke at 32 degrees would completely black out the road if I would let it. I pretty much have to watch the mirror to keep from putting out excessive amounts of smoke (or turn the DSP5 down to a lower tune but then it is really sluggish)

It has Idaho Rob EFI Live tuning and injectors were replaced recently and that made no difference with the smoke.

It has been doing this for years.

Mine is the exact same way with Robs tunes. The corners of my truck will turn black just driving around one day. I talked to the guys at ATP and am going to send them a log hopefully this week.

 

[Bustedknuckles]

This is one day of driving. I hand washed it and drove it home from work and then drove around Saturday and it looks this bad already!

 

[thunder550]

My LLY seems to smoke more in the heat as well.

 

[THEFERMANATOR]

This is one day of driving. I hand washed it and drove it home from work and then drove around Saturday and it looks this bad already!

I put a turn down on ine because I got tired of the soot on the quarter panel.

 

[Bustedknuckles]

I put a turn down on ine because I got tired of the soot on the quarter panel.

It pains me to do that because I hate the looks of them especially since I have duals but I may have to.

 

[whatnot]

Thanks for all the replies. The posts by PACouger just made me think of something, the climate control turns on the A/C at 50 degrees. Maybe that does have something to do with it.
I haven't used EFI Live that much. What exactly should I log?
I have had the tune for a couple years now. I did call Rob about it once because the other guy there I talked to before buying it kept going on and on about how bad smoke was and how they make clean tunes. When I talked to Rob, I was just trying to ask if it was normal but he was apparently getting impression that I was complaining. I got no where with the phone call and didn't try again.

Is there a better tune to try that is similar performance without all the smoke?

 

[whatnot]

This is one day of driving. I hand washed it and drove it home from work and then drove around Saturday and it looks this bad already!

I have Line-X on the bottom of my truck so I don't have that problem.

 

[Dozerboy]

This is one day of driving. I hand washed it and drove it home from work and then drove around Saturday and it looks this bad already!

Thats more of a problem of your tip not sticking out enough. I had to add a tip to my new exhaust it was so bad I couldn't drive 5 miles without soot on my fender. Mine is now just a little past the tire, but I also have mud flaps that probably made me have to go out farther.

 

[whatnot]

I think this is cracked above the bottom rib. How much would that contribute to the smoke problem?

 

[02greysixer]

An exhaust leak could create more smoke for sure. And like dozer said that soot on the fender has a lot to do with tip placement. You either need to bring them out and away from the fender or pull them in basically under the truck. I went the pull it under the truck route with my white truck, I never really have soot on my fender.

 

[NC-smokinlmm]

I think this is cracked above the bottom rib. How much would that contribute to the smoke problem?

That's not gonna cause excessive smoke if it's cracked. It's in the tuning like I told you before...