Engine won't shutoff!

[1stgensleeper]

So last night I was at a friends party and he wanted a ride in the ol' girl, so i took him out, made a few hard runs and went back to his house. I let the engine cool down but when i turned the key to the off position, it did nothing. I tried it a few more times and it still wouldn't shutoff. So i then pulled the boot off before the intake horn and choked the engine with a large, flat, thick piece of plastic. The engine then shutoff. What would cause then engine to not shut off? I posted this in the electrical section because I'm convinced that it's something in the ignition system. Any suggestions are greatly appreciated.

[RumbleFish]

Sounds like you need a fuel shutoff solenoid, or fss. Do you have the fuel cranked up a lot?

[1stgensleeper]

I have the pump turned up 2 3/4 turns with an m&h #4 fuel pin. Thats basically it for fuel mods.

[cmann250]

Hammering it and then letting off quickly isn't good for the FSS. The end chips and can get stuck in the DVs. If the end is chipped, it doesn't cut off the fuel

Mine's been turned up for a year plus and I've yet to have a hiccup out of the FSS, which I find odd

The lever on the side of the pump shuts it off. Counter clockwise is I remember right

[PToombs]

Counter clockwise is I remember right

It only goes 1 way buddy, and clockwise it is.

If you don't want to keep buying shut off solenoids, you can put a cable on the shut off lever. I personally don't like them, but lots of guys have them.

[cmann250]

Counter clockwise is I remember right

It only goes 1 way buddy, and clockwise it is.

It is CCW, I went and checked. It has to be to make it a PULL cable. Just trying to help the new guy

[BC847]

You're both wrong.

As seen from the driver's seat, one simply pulls on the bottom of the lever. It is spring-loaded and as found, only moves one way.

See the attached image (Mechanical Fuel Shut-Off).









As cmann250 mentioned, with turning up the fuel and hammering it, the increased volume of fuel flowing past the FSS plunger and into the associated orifice, tends to rip a plug from the plunger and sucks it into the Head/Rotor assembly where it either goes into the Delivery-Valve(s) (DVs), or back into the case by way of the Fuel Control Collar.

You said you took it out to show a friend how well it runs (basically ), that suggests you're gonna continue to beef it up, a little more anyway. Assuming that's the case, you'd do well to learn to "Roll Of The Throttle" instead of side-stepping the throttle. The FSS will survive in that setting (with a little modification) and there's a good chance you'll avoid other possible fuel system problems as well.

Just my $0.02.

[1stgensleeper]

I have heard that you should roll out of the throttle and i always try to for those very reasons. When I turn the key to the off position, what goes on in the injection pump that makes the engine shutoff? Is the shutoff solenoid activated which causes the engine to stop? Thanks for the help guys, I need to get this thing fixed quick.

[1stgensleeper]

BTW, I'm sorry if I posted this in the wrong section. I figured it was an electrical issue. Silly me!

[PToombs]

I forgot the lever hangs down not up!

Under the solenoid is a spring and a plunger. The solenoid is a coil and the magnetic field of it being on pulls the plunger up against the spring. When the power goes off it drops and covers the hole the fuel goes thru. When it chips the fuel goes thru the chipped spot and keeps the truck running, usually at a lower idle.

[1stgensleeper]

Ok, so that would mean that I dont have a chip , or a freaking huge one because when I turn it to off, it doesnt change rpms at all. I think the solenoid is just bad, because I always try and roll out of the throttle rather than yank my foot off of it. Thanks for all the help guys.

[PToombs]

Yup, sounds like you tore off a big piece of it. Search around on here you can find a link to them fairly cheap, about $30 IIRC. If you want to replace it that is.

[1stgensleeper]

Is there a posibility that the solenoid is bad but not chipped? I was also wondering if it is chipped, will this chunk of solenoid do any damage to my pump/engine?

[PToombs]

If the solenoid was bad it wouldn't start, that part is the coil. The plunger is the part that moves and has the rubber tip on it. I tried gently sanding mine down to give it a new edge on the tip, (it's shaped like a cup on the end) like others have done, and it didn't work for me. I used a wire wheel and removed the rubber, then welded a small (like a #6) nut on the end and run it that way. It seems to work for me.

I've read on here that the missing piece will lodge in the delivery valve (DV). It will just restrict fuel to that injector. I've lost several and haven't had a problem yet. But don't go by my results.

[BC847]

@ sleeper: In the top of the two images depicted above (fig. 17),

Part no 4 is the fuel shut off solenoid (FSS). That black arrow shown pointing down is on the plunger of the FSS. Where the tip of that arrow is, is the rubber tip we're talking about.


Hope this helps.