I thought my truck has been a little smokey on these cold mornings. Found out the KSB isn't coming on. It's the thermostatic switch in the manifold. I applied 12v directly to the KSB, and, Presto!, the smoke cleared up and she was far less clattery. Anyone know what temp it's supposed to switch at? Thanks!

 

I was told that it is supposed to cut out at 90*F at the manifold.

 

You were told correctly.

 

So it was the thermostatic switch for sure. Got a new one yesterday. The new design is better. The bulb has fins so that it can react to air temperatures quicker. $35 from cummins. I did have to educate the parts guy that this part even existed. He kept telling me I had to go to Bosch for anything to do with the injection pump. I kept saying, No it's screwed into the intake manifold. It all worked out in the end.

 

part number please?

 

What does the KSB switch regulate ? Not sure if this is related, but is it common for the Cummins to turn-over like 3 or 4 times on cold starts (outside temps 20 - 25 Deg. F) with no plug in.

 

The KSB causes the timing advance mechanism to "lock on" after a cold start. This reduces white smoke and makes the engine run better. It does not affect starting.

3 or 4 revolutions or you have to crank it 3 or 4 times? 3 or 4 revolutions I'd say the battery is tired or you have some resistance in the wiring. Having to crank it 3 or 4 times to get it to light off I'd say the engine is tired.

 

Sorry...I meant 3 or 4 revolutions, but this only happens on the coldest days. Would a newer stronger battery make a difference? I think mine is a little dated.

 

Probably. Check for voltage drop across the cables before spending money on a battery, though. Disconnect the shutdown solenoid so the engine won't start, then put a voltmeter between the positive battery terminal and the starter terminal. Have someone crank the engine over. You should see no more than 0.2 volts. Do the same thing on the negative side (negative terminal to engine block ground point). If you see more than 0.2 volts, clean the connections and try again. If it's still bad, replace the bad cable(s). If it passes the voltage drop test, then put a battery in it.

 

Part number is 3408645. Merry Christmas!!

 

It should only take a couple of compression strokes....even in the single digits F mine will fire on 3 or 4 compressions.