12HT not switching off?

[negneg]

My 12HT does not want to switch off.... she starts with half a turn of a key and idles fine... i drove to a shop and when i got there, i turned her off, depressed the button switched ignition off and she continued to idle....???

(i had the motor rebuilt in January this year and i noticed that after the build, i would switch her off and she would idle for about 3second and then the motor would stop... i sometimes was quick on the key and it was out of the ignition before the motor switched off. )

the ignition went off, all gauges dropped and there was no power to the sunroof as when it is on the ACC position... but cruiser still idled. i stalled her to stop the motor. i then went to the fuel station, same thing would not switch off... stalled her again..... then when i reached home, i parked as always and switched off the engine expecting it to carry on and it switched off after about 3 second as usual....

has anyone had this issue before and what was the "fix/solution/culprit"

thanks

 

[Granite Grinder]

Probably better to post this in the diesel forum, if you haven't already.
I'll take a stab though, I believe the 12H-T uses a VSV valve to move a butterfly vane in the air intake to "choke" the engine, which in turn shut the engine off. At least that's how it works for a 13B-T. I'd check to see if the VSV (Vacuum Switching Valve) is functioning. I don't have a 12H-T, so I don't know the location but it shouldn't be hard to trace.
Again, I don't have a 12H-T, so the mechanics for extinguishing the engine might differ i.e. EDIC motor

 

[Dynosoar]

There is a thing called an EDIC (Electronic Diesel Injection Cutoff, I think) that cuts the fuel to the injection pump. That should be checked first, it may just be a loose wire.


Dynosoar

 

[dirtfriendly4x4]

There is a thing called an EDIC (Electronic Diesel Injection Cutoff, I think) that cuts the fuel to the injection pump. That should be checked first, it may just be a loose wire.


Dynosoar

x2 to dynosoar.. i have a 2h i never used the EDIC. i just connect a cable to the cutoff switch using a hood open cable. so my 60 will still be on even when the key is on off. the engine will only stop when i pull the cable to the plunger which chokes the fuel going to the pump.

my edic used to be on top of the starter side, mounted near the firewall on the intake manifold nearest to the firewall and intact with 2 size 12 bolts.

if your looking at the engine bay it will be on the left side of your view. if your looking from inside the car it will be on your right side of the engine. i hope this helps good luck.

 

[daboheme]

12H-T doesn't have EDIC. Has a vacuum activated butterfly valve to starve engine of air, thereby shutting it off. You can manually shut it off no problem. Valve is just before the intake manifold. Check for vacuum leaks on piping. Had the same issue a while back.

 

[Dieseler]

X2 on the VSV check the hoses had the same problem once I blew out the valve and it has worked since then. .

 

[negneg]

Ok, will check it out. is it just a switch that needs replacing??

 

[Granite Grinder]

x2 to dynosoar.. i have a 2h i never used the EDIC. i just connect a cable to the cutoff switch using a hood open cable. so my 60 will still be on even when the key is on off. the engine will only stop when i pull the cable to the plunger which chokes the fuel going to the pump.

I'll wager your 2H is in front of a manual transmission, the 2H with an automatic transmission uses a VSV, same as a 12H-T.

 

[Granite Grinder]

Ok, will check it out. is it just a switch that needs replacing??

Like others posted above, check the tubing first, then I'd check the wiring. The valve isn't prone to wearing out, they do, but I'd suspect vacuum or electrical first.

 

[dirtfriendly4x4]

I'll wager your 2H is in front of a manual transmission, the 2H with an automatic transmission uses a VSV, same as a 12H-T.

well i never had a 2h in automatic transmission. thanks for the info though
i had a 13b but also uses the pump thing on manual. so yah i'd check hoses for the vacuum to the valve thing.

the best thing in MUD and its possibilities

 

[alpha eddy]

it happened to me... check your vsv (check manual) and then check your battery life..... always happen when battery to low.... then check the vacuum hose...

 

[negneg]

So i traced it to a cracked vacuum hose. cut about 1" of either side it problem solved!

trimmed all hoses while i was at it!

thanks guys!