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johnhicks · 05-17-2022, 06:38 PM

1992 6BT

Last September I had a no-start situation but I hand-actuated the old fuel solenoid a couple of times and gave it a squirt of T9. That fixed it until December when the problem recurred but I was actually arriving to check into my winter park.

I replaced the fuel solenoid and all seemed well upon testing. I've been sitting about five months. This morning trying to crank up to go to a shop for an oil change was no-go. I squeezed the solenoid a couple of times, and it fired right up.

The shop guy found it impossible to get it started without manually pushing the solenoid up, but he couldn't get into diagnosing anything and we couldn't stay there.

Now, back at he CG...it feels like the entire mechanism is binding against something when it goes down, or off, and the pull voltage can't pull it up to start. I haven't found anything it could be binding against.

And now a repeat. I gave the entire linkage a good wash of T9 and worked it a few minutes. No binding, and it fired right up! It's a new solenoid and obviously I'm getting the pull voltage, so what could be binding?

Is it possible that the valve it's rotating is actually binding, or a seal? Ideas?

Thanks in advance.

wolfe10 · 05-17-2022, 06:51 PM

Do you have the new/improved/quite a bit larger than OE fuel shutoff solenoid?

Have you verified voltage to it-- low voltage can cause the same symptoms.

And, as I suspect you know, the "work around " is to wire it open for "run" and release it to shut down the engine.

johnhicks · 05-17-2022, 08:08 PM

I have the Chinese version, which appeared to be the same size as the original, and the mounting holes match up. As for voltage, when it wouldn't start we tried boosting with house batteries and still no-go. Checking actual voltage is on tomorrows project list.

The odd thing is that I could feel it binding in the down position but couldn't after squirting T9 all over everything...and then it started.

Is it possible for that valve (?) or shaft to bind up in that way? If this is something I'll need to take the oil can to regularly that's ok, but it seems strange.

153stars · 05-18-2022, 07:55 PM

A magnetic solenoid/coil likes to have it's steel/iron core fully engaged when energized or coil will over heat. If there's a plastic sleeve or bore may have melted some . Maybe you can disconnect it and manually work the crap out of it to temporally free it up some. Just buy another.

johnhicks · 05-18-2022, 09:19 PM

The solenoid bottoms out when engaged.

I was fiddling around with it today and found that after bathing the linkage (not the solenoid itself) in T9 the mechanism moved freely with no binding at all. Since T9 is essentially super-WD-40, I gave what I believe is the pivot point a really good squirt of Pacbrake high-temp oil; that may last longer than T9. We'll see what happens.

Has anyone ever seen any instruction to lubricate the valve shaft?

Alpine36 · 05-18-2022, 10:00 PM

I seem to recall the 6BT electromechanical fuel solenoid is controlled via a relay. (at least our old fleet of Freightliners were way back when)
Don't overlook that relay and associated wiring for any voltage drops.
For some reason my aging brain cells recall a few of those relays failing...
Good luck

153stars · 05-19-2022, 06:48 PM

I don't it as far as having hands on it but some solenoid kits had the rest of bell crank parts as well

johnhicks · 05-19-2022, 09:14 PM

Where might that relay be lurking? This is an Oshkosh XC (Freightliner XC) chassis. I looked inside the rear frame rails I could see, but...

johnhicks · 07-24-2022, 10:28 AM

I believe my problem has been resolved by lubricating the linkage and a new starter battery.

ArtJoyce · 07-24-2022, 11:04 AM

John, I think I would replace it or get a spare part. Last thing you need is for it to fail in nowhere land with no part available for days.

johnhicks · 07-24-2022, 12:36 PM

The solenoid is new too; that's what was puzzling. I replaced the solenoid but still had problems. Never did find a relay.

Raider10000 · 08-04-2022, 02:04 PM

I have a similar no start situation after my 2000 Dutchstar Cummins 330 ISC sat for about 4 months. I have looked high and low, even removed the upper cover in the bedroom, but cannot find Fuel solenoid Valve or the linkage. Anybody got any ideas? Thanks