HELP BLACK SMOKE WHEN COLD

[DILLIGAFRI]

Help 98 K-1500 90K miles Truck runs great but smokes bad when cold. Had prob with wastegate solinide and replaced that and boost sensor also. Bad smoke when cold, not as bad warm but noticable up till 1600-1800rpm then goes away like I turned off a switch. Any ideas I am starting to wonder about the PMD? Truck runs great up to 90mph
Thanks
Dave

[Polar Diesel]

Did you check all the EGR equipment?

[DILLIGAFRI]

I hadn't thought about the egr since it is black smoke and has no codes. I had a code for the wastegate before I changed the solinoide.

[Polar Diesel]

well i would guess if your dumping way too much exhaust in it might burn too rich, alot less oxygen especially at idle. The computer shuts the egr down as you increase power demand. It would be worth checking. Un hook and plug the vacuum line to egr valve and run it, see what happens.

[charliepeterson]

Un hook and plug the vacuum line to egr valve and run it, see what happens.


"This is the Test Mode for off road use only"
Very good advice!

[Scooby]

Dont unplug the electrical connector for the egr solenoid though. It will cause a code. Just disconnect & plug the vacuum line. Thats the way mine has run for a while now. While maybe unnecessary, I also installed a "TEST PLATE" :D in place of the egr valve just in case the valve could be pushed open by exhaust pressure. I used a piece of 3/8 plate, and the original bolts.

[DILLIGAFRI]

Pluging EGR has stoped the smoke !!! However I got a service engine soon light this morning Guess I will have to check the codes again tonight. One prob solved but created another