This is a helper thread for future readers, not a question.

There is some bad info out there about this simple little solenoid. I found out because I've recently been through the ringer with my 22r carb not idling, and this was a suspected culprit for a while.

The bad info is that

A) You need this solenoid for the truck to run properly (mostly false)
B) This can cause idling problems (mostly true....key word "CAN")
C) The white wire is a ground wire (mostly false)

I'd just like to clear this up for future mechanics.

All this solenoid is intended to do is prevent dieseling when you turn the truck off. That's it AFAIK....nothing else. It does this by opening up (ie. letting fuel in) when voltage is applied, and closing (cutting fuel off) when voltage is taken away....and voltage is (or SHOULD BE) applied by turning the IGN ON, and it's taken away by turning IGN off.

So, It will only cause idling problems if it's closed or partially closed/stuck or not receiving voltage....in which case it will likely cause a lean condition and starve the carb of fuel. But on it's own, it will never cause the issue I was having, and I've seen some other people go through (ie. way too much fuel, truck running too rich). Again, all it can do is cut off fuel, not add more fuel on it's own. So that was never a feasible culprit in my case, and I suspect many others. Nonetheless, I replaced mine with a cheapo Chinese one that seems to be working fine.....for now anyway.

It's also worth noting, unlike what has been said in some forums, the white wire on the fuel cut solenoid is not ground, it goes to the stupid emissions computer by either left or right side kick panel (was right, US passenger side in my '86 4wd truck). This computer probably controls a ground connection to that white wire.....so it should usually be getting ground on that wire, but it has to go through the dumb emissions comp to get there. So calling it a ground wire is mostly inaccurate. It seems to be switched via the comp. On my truck, the emissions comp seems to be worthless, and there is no ground on the white wire no matter what I try (pulled comp, resoldered all connectors, replaced a bad diode....still worthless). The cheap Chineseum fuel cut solenoid off Fleabay is actually a better/simpler design. It's a single wire, which is hooked to the black wire, which receives voltage when IGN is on (thus allowing fuel to flow) and receives no voltage when IGN is off (thus cutting fuel)....it gets ground direct from the carb body (just like choke heater and outer vent). No emissions computer involved....very simple and effective. So I'm either going to keep this one one, or fix my stock solenoid with tons of ultrasonic bath and carb cleaner and then solder the white wire to the solenoid housing, so it's always grounded via the carb body....or just wire the white wire direct to ground.

Either way, the take away is that if you want to eliminate this solenoid as a possible source of trouble with idling/running.

1. It's only a possible problem if you're starved for fuel....it'll never cause a rich condition on it's own.
2. If unsure, just remove it and plug the hole with a short bolt (not one so long that it might go in all the way and block the passageway). All that will happen is that turning IGN to off won't immediately cut fuel, so you might get a little dieseling. Otherwise, it will allow fuel to flow properly as it's supposed to, completely eliminating this solenoid as a possible problem.

 

Why is there a blank space in your discourse (posting)?

Because you cut-and-pasted two paragraphs from somewhere else. For some curious reason, when you do that the color is set to black-on-black (i.e., invisible).

Just hit Edit, highlight your "missing" text, select the Font control, then set the color to Automatic. Don't use any other color, unless you know what you're doing.

 

do you have a link or product number for the solenoid you found? I can’t seem to find one anywhere