What function does the KSB solenoid valve have?

[BSMcCauley]

A buddy of mine has aquired his dad's completely stock 1990 2500 2WD truck. It seems that after 380,000 miles the turbo diesel wore that truck out. As a side note, the only maintenance that has ever been performed on this engine is regular oil and filter changes and they never ever had any trouble with it. After sitting for almost a year, it fired up when the first injector fired without even having a fuel line connected to the lift pump! Anyway, my friend is on the home stretch of cramming that Cummins into his old International Scout 4X4 after that truck wore out it's original engine. While rigging up the wiring, we were trying to figure out what the function of the KSB solenoid valve mounted on the injector pump is. It appears to have been wired up with the manifold grid heater so that when the grid heater is off, the KSB valve is on. I told him not to worry about what it does, just hook it up the way the Dodge boys had it, but he wants to know why it is in there. Any ideas out there?? Thanks for the help!

 

[paccool]

The short answer is it is a "cold start solenoid" that advances the injection timing until the engine warms up. It uses a temperature switch mounted in the intake manifold, the switch is open above 90 degrees F. Below that the KSB is turned on.

 

[BushWakr - RIP]

The KSB, as paccool noted, is for increasing the pump's internal pressure thereby effectively raising the 'timing'. This reduces emissions, and smooths out the idle when cold.

The heater elements warm incoming air on cold starts. Both can/will function together if required by outside/incoming air temps.

They are not mutually exclusive.

In other words, one of them running does not exclude the other from working ...



bob.

 

[BSMcCauley]

Thanks for the info!!

 

[Greenleaf]

I was wondering what that was. The busses don't use it. Scott