bigragu

On my D250, there are 2 wires connecting on 2 male electrical prongs side by side to each other. There is one blue wire, which is bunched with the wire going to the TPS sensor, and a red wire bunched withe the wire attached to the KSB solenoid. They are attached to the 2 prongs close to the power screw, underneath the AFC housing boost line. On my 93 D250, the blue line connected to the prong pointing towards the drivers side wheel well, and the red line connection points to the firewall. On my W250, the wires are flip flopped. Please explain what these are for, and is flip flopped OK? If not, where should they be?

Chrisreyn

OK the connector under the fuel screw is the Fuel Shut Off Solinoid( FSO )
It does just as the name implies, shuts off the fuel flow to teh engine when you turn teh key off.
the wiring runs from teh FSO, to teh temp sending unit (rear of block, top drivers side) to teh KSB..I may not be exactly right on this, I am going from memory which gets weaker every day, but it the basic circuit is as I describe
IIRC the blue with a black tracer goes to teh temp sending unit and the red/white is the poewr to teh FSO.
If you'll do a search of FSO, there are numerous threads about the wires and problems with them. The mostcommon of which is the FSO wires having a loose or poor connection, causeign the engine to cut out or a no-start situation.. the fix is to replace the spade terminals with a ring terminal on teh FSO.
Some only have ONE wire at the FSO....

wannadiesel

It doesn't matter, the two prongs are part of the same piece of metal, it's used as a junction block.

bigragu

Thanks, people.

BearKiller

Is that a blue wire, with a white stripe, that I see plugged to the KSB terminal?? (I think I named it right--the other gizmo, down low on the left side, that has the wire connected.)

The non-IC 91 model, that I just bought, has no wire hooked at that point.

There is a long blue/white-stripe wire, with female connector, hanging loose from a plug-full of wires, that will reach that point easily.

On my 89 engine, the wire is a short jumper from the FSO, ?? I think??.

What effect does it have on the 91, with no wire connected to the KSB??

Thanks.

wannadiesel

On the non-intercooled trucks it advances the timing if it's unplugged.

BearKiller

Is this ^^^^^^ the wire I want??

Thanks.

wannadiesel

The information I have says the wire is dark blue. Plug a test light into the wire in question and start the truck from cold. You should have light when the engine is first started and the light should go out as the engine warms up.