I know this has been beat to death, I'm sorry. My '89 CTD on start up will puff a cloud of black smoke, (normal), but then it blasts out blue smoke for as long as it wants until I get the old truck moving and seems to clear up after 1/4 mile. I know most big trucks smoke blue at start up, including since it is getting cold. I pulled the DP and checked to see if there was any oil in the pipe and there wasn't. Other threads were talking about a sensor, but my non intercooled motor doesn't have any. Does it? Gid heaters kick on everytime it's around 40degrees out. What do you think is causing the smokin? Besides she's old, and 250,000 on her feet.

 

Sounds like the KSB isn't working. Take the relief valve out of the KSB housing (looks like a bolt on the end that doesn't have a wire) and make sure the plunger inside isn't stuck.

 

The KSB sensor is on the intake manifold and allows power to the solenoid on the pump to advance timing. check with a test light if you have power going in from the fuel shut off solenoid and coming out from the sensor. It should be the rear one of the two that are there. (the other is an IAT) No power coming out you need a sensor. To verify you can put the sensor in the freezer and check if it has continuity or not. (it should if operating correctly) I think it allows voltage to the solenoid until it reaches 15C. Part number should be 3408645 from Cummins about $60 CDN.

 

The early CTD's aka non ic have a constant supply to the KSB unlike the ic models which are opposite. To make the timing advance on them you need to remove the 12v power supply. I am not sure how to test them electrically but I would do what Wanna said and make sure the plunger is free. I am going to check mine on Friday. I never really paid attention by mine does push some blue smoke out at idle also.

Ryan

 

Guess someone beat me to the reply. The way I explained it is for Intercooled only I guess. Testing electrically would be the opposite heat it up and check for continuity.

 

Sorry I hope that my reply did not come off sounding rude. I have been reading some posts about hot wiring the KSB to get more timing and I actually just unhooked mine and I can't feel a difference that is why I am going to pull mine apart Friday

 

Thanks for all the replys, I was hoping it would be something simple. Anyone have picts or a write up on the KSB? I would like to get this fixed, some people at work aren't impressed by the fog in the parking lot.

Just found a pict. Do you just pop the connector off and loosen the big nut and pull the whole thing out?

 

Wait'll it gets real cold:



I'm not aware of any writeups, but maybe there's some pics floating around on my harddrive--I'll have a look-see

 

Sweet pic. I just saw someone else posted a blue smoke post, and wanna said check the voltage at the ksb. On the '89s do they have constant 12v voltage until the engine warms up? or does it get voltage after it is warm? Thanks again guys.

 

Non intercooleds get 12 volts when the brain box says it's warm enough. There should be no power to the KSB on a cold start.