Too much black smoke

[dheavychevy38]

Ok i have a 97 chevy 3/4 ton 4x4 the truck is stock except a straight through exhaust. I have 113,000 miles on it. The problem is when i am towing my trailer or have my a/c on it smokes so bad past half throttle it has me worried that i will get a ticket and i feal bad for the people behind me. I have a fresh oil change,air filter, and fuel filter. I have tried fuel treatments. I have 15 in at the turbo and 25 in at the pump. You can hear the turbo out of the exhaust at around 1500 to 1800 rpms anything past that nothin and then the blake smoke. I have guages on order so i don't know what boost is yet when driveing. Any idea's would be great Thanks Denny

[93GMCSierra]

Sounds very possible that your not getting any or enough boost at higher rpm. Could be vac related from the sounds of it, or possible the wastegate is sticking?

[dheavychevy38]

The wastegate moves freely when the truck is off. I was thinking of running a t off of the wastegate and run a line in the truck with a vaccum gauge and go for a ride.

[JohnC]

I think you will find the vacuum drops to zero when the smoke starts. Most likely the wastegate solenoid is failing, but it has a small filter you can try cleaning first. Any DTC's?

[dheavychevy38]

the only one is p1216d that is the only code

[cheyenne1500]

Try to block off the egr. That has been the root of many of my problems. my truck has no more egr and its been running strong for a long time!

[dheavychevy38]

Mine is the f motor which means no egr i think