12HT Shut off Butterfly (1 Viewer)

[LyndenCruiser79]

Hey guys,

I know that this is an old thread.... But I ran into the same problem.

I have a 1987 HJ61, I recently replaced the turbo and put everything back together and now the 12 HT wont shut down.

I followed the manual's suggestions for checking the VSV and the actuator... it all seems to be working well, full travel on the butterfly valve linkage from run to stop... no problems there... I suspect either a bad seat on the butterfly valve or the intake is sucking air somewhere...

My question is this: Is there a way to test for an intake suck? I've heard of starting fluid, or ether... is this a dangerous way to test??

Any suggestions or advice is welcomed!

 

[roscoFJ73]

You dont use starting fluid for this.
Can you visually check the butterfly valve? If it wasnt closing there would be a gap.

 

[Greg_B]

While the engine is running move the lever at the butterfly vacuum pot by hand to close the butterfly valve. Does the engine shut down? If it does it's got to be in the vacuum or electrical signal wire to the VSV.

hth's
gb

 

[LyndenCruiser79]

While the engine is running move the lever at the butterfly vacuum pot by hand to close the butterfly valve. Does the engine shut down? If it does it's got to be in the vacuum or electrical signal wire to the VSV.

hth's
gb

I performed that test and it did not shut down... I will have to pull the air connector tube off again and do a thorough inspection of the butterfly valve/seating, but there was nothing super obvious yesterday when I looked at it.

As far as testing the VSV, I blew through the tubes with it disconnected and verified that it is functioning properly (with and without power).

I also looked at the butterfly valve linkage from the actuator and its action looks good (hitting both open and shut stops fully).

That is why I am narrowing down on either butterfly valve not seating properly or a leak on the intake manifold assembly...

I know on gasoline motors, I have used an unlit benzo torch to diagnose an air sucking problem... worked well for that, just wondered if I could do something similar with a diesel motor, either propane, starter fluid, etc.

 

[roscoFJ73]

Does the engine stumble or change RPM when you try to shut it down?

Have you done a search on MUD, you are not the first to have this problem?

12HT Wont Shut Down-help please!

Hey guys, my HJ61 12HT won't shut down when I turn the key off and I have to stall it out to shut it down. I turn the key off and the turbo timee keeps it running, which I hit the stop button straight away unless I've been on a long run and that turns it off as normal. Now I hit the off button...

forum.ih8mud.com

 

[LyndenCruiser79]

Does the engine stumble or change RPM when you try to shut it down?

Have you done a search on MUD, you are not the first to have this problem?

12HT Wont Shut Down-help please!

Hey guys, my HJ61 12HT won't shut down when I turn the key off and I have to stall it out to shut it down. I turn the key off and the turbo timee keeps it running, which I hit the stop button straight away unless I've been on a long run and that turns it off as normal. Now I hit the off button...

forum.ih8mud.com

The engine does drop rpms with the key off.

I searched the forums, didn't really find something quite like this. Sounded like most guys just gave the actuator some TLC and it all functioned again, or installed a automatic shut off cable to pull in that butterfly valve. Unfortunately, my problem is something else...

 

[roscoFJ73]

If the butterfly valve is the sole component that shuts the engine down, then obviously it is not closing properly or there is a big leak some where. You mentioned squirting some starter fluid around the possible areas of leakage, I would use some light oil. Dont drown it, just a few drops to see if it gets sucked into the engine.

 

[LyndenCruiser79]

If the butterfly valve is the sole component that shuts the engine down, then obviously it is not closing properly or there is a big leak some where. You mentioned squirting some starter fluid around the possible areas of leakage, I would use some light oil. Dont drown it, just a few drops to see if it gets sucked into the engine.

That's a great idea. I'll try that on the next opportunity I get to fiddle with it.
Thanks!

 

[FJBen]

That's a great idea. I'll try that on the next opportunity I get to fiddle with it.
Thanks!

Did you ever get around to checking this? I've got a 13BT and it just started doing the same thing. I 100% suspect it's sucking air in the intake, some of those bottom bolts are a pain to get to. And replacing the intake gasket is a pain.

 

[LyndenCruiser79]

Did you ever get around to checking this? I've got a 13BT and it just started doing the same thing. I 100% suspect it's sucking air in the intake, some of those bottom bolts are a pain to get to. And replacing the intake gasket is a pain.

So... I finally found time to pull this apart and it appears that the butterfly valve plate was bent... I tried some field metal forming ... which improved the shut off prob... but not entirely... I think I may have to pull that whole throttle shutter block off and put it on a workbench to get it to properly seal. It's tricky because it really doesnt take much deformation to have a problem... did you ever have any luck with yours?

 

[FJBen]

So... I finally found time to pull this apart and it appears that the butterfly valve plate was bent... I tried some field metal forming ... which improved the shut off prob... but not entirely... I think I may have to pull that whole throttle shutter block off and put it on a workbench to get it to properly seal. It's tricky because it really doesnt take much deformation to have a problem... did you ever have any luck with yours?

Yep, I had a bad fitting intake gasket. Bought the OEM one and all was well. As long as it’s straight you should be good. There are 2 stops that I think are Allen keys, that limit how far the shutter goes each way. Those also make quite a bit of difference. Fairly easy to pull it all off and inspect it.
Very strange that it’s bent.

 

[KamarulF]

My 12HT recently had similar issue in the butterfly but mine was engine shutdown which was caused by faulty relay and earthing. As i was 2 hours from nearest workshop, to start it back, i unplugged one vacuum hose from gearbox, start the engine, unplug hose to actuator, then plug back vacuum hose to gearbox. Just to share