Is this means bad injectors

[dersark]

My 04 duramax has 43000 mils with no problems, excellent power. If I do hard acceleration black smoke comes out of tail pipe. Is this means anything. Thanks, Sark

[DmaxMaverick]

LB7 or LLY? It doesn't sound like injectors with either.

If it's an LB7, you probably have a dirty air filter or the boost isn't spooling. Check the boost hose that goes from the turbo compressor housing to the wastegate actuator (small 3/8" rubber hose).

If it's an LLY, the turbo vane servo has probably failed, become loose, or the connector is loose/dirty. Not too uncommon, and a warranty item (5yr/100K). Do you have any DTC's (SES lamp on)? Could be a dirty air filter, just the same.

[dersark]

It is LB7 and air filter is clean according to the indicator. I do not know where to look for that hose. Thanks

[DmaxMaverick]

It is LB7 and air filter is clean according to the indicator. I do not know where to look for that hose. Thanks


The hose nipple sticks out of the forward part of the compressor housing (aluminum snail looking thing). Visible if you remove the black plastic cover. Or, follow it from the WG actuator, which is the canister on the RH (US passenger side) of the turbo. Just a ~10" black hose, with nothing on the hose between the actuator and turbo.

[JohnnyR]

DmaxMaverick

If it's an LLY, the turbo vane servo has probably failed, become loose, or the connector is loose/dirty. Not too uncommon, and a warranty item (5yr/100K). Do you have any DTC's (SES lamp on)? Could be a dirty air filter, just the same.

If the turbo vane servo has failed, will it set a DTC? My LLY smokes a lot when I get on it. I thought it was just because I don't get on it often. Where is the servo located so I can check the switch.