What is the solenoid on the side of the pump for? The connector broke on mine and nothing happened....

I just found it, KSB? cold start solenoid. What does it do???

 

Advances the pump timing around 5* when the solenoid is powered via a thermal switch in the intake.

 

THe only "Dumb guestion" is the one that you didn't ask.

 

Is it an additional 5deg over the full advance of the pump? If it is I could wire it to a hobbs switch to activate that solenoid at 20 psi or so.
Just a thought...

 

Doesn't quite work that way, full advance is full advance and activating the KSB at full advance won't to anything usefull. What it does is increase the internal pump case pressure which intern pushes the timing piston further in the bore. Its usually a bad practice to use the KSB for additional timing, it could compromise seals and usually burns out the solenoid if used for lengthy periods of time.

 

It appears to be the same solenoid design as the fuel cutoff solenoid which is a continuous duty unit. But if it doesn't buy me any extra timing I can forget about it. It was just a though. I really need to pull the pump apart and shave that piston down a bit.

 

So on the intercooled trucks the solenoid should have voltage when intake temps are low and the key is on, right? I checked mine one morning just after I started the truck and had 0 volts (probably about 40*F).

 

That's correct. That's the wrong way to check it, though. If the grids were working then the switch may have been too warm. Same issue if it was plugged in. The best way to check it would be to disable the grids by pulling one of the coil wires off each relay, then turn the key on and check for voltage at the KSB.

 

Thanks for the tip, I'll try that just to make sure it's working.