12HT cold start issue
- Thread starter CenTXFJ60
- Start date
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Man i need to get a straight pipe on mine.. so jealous haha..
Mine kinda starts like yours but i just hold the key on longer than the normal "flick" once i held the key it finnaly turned over and stayed on..
that white smoke is normal when cold mine was puffing white till warm and was idling at 1000 rpm or so again till it got warm..
You said its just this 12ht of yours that does this? Is your fuel turned up more than normal?
Mine kinda starts like yours but i just hold the key on longer than the normal "flick" once i held the key it finnaly turned over and stayed on..
that white smoke is normal when cold mine was puffing white till warm and was idling at 1000 rpm or so again till it got warm..
You said its just this 12ht of yours that does this? Is your fuel turned up more than normal?
Glow the damn thing. Not enough heat. My 13BT does the same thing without enough heat. I have been around diesels since the mid sixties, every diesel I have been around does that without enough heat. You should have seen the old Allis Chalmers smoke when started with the little gas kicker motor, it looked like a forest fire until the diesel warmed up.
Have a look at the shut down butterfly when your trying to start the engine. If the vacuum is low the engine wont fire until the vacuum builds opening the valve/butterfly. The fuel injection is still working causing your grey/black smoke when it does fire. Check your vacuum lines for a leak.
CenTXFJ60
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- Thread starter
- #25
You are right about that. I plan to source some 12V relays so I can do this. I plan to research what other folks are using when converting from 24 to 12V. But on the other hand I’ve had 2-3 other 12HT’s (2 without glow screens functioning) and they fire right up.
Uh, 12H-T's should start even without glow or preheat. The factory glow is not much help anyway.
But definitely check how the butterfly operates.
Did you service the injectors? 30 years without operating can leave a mark.
But definitely check how the butterfly operates.
Did you service the injectors? 30 years without operating can leave a mark.
Yes it works. Outside temp was somewhere between -0c / -5c when i recorded the vid, looks like it wasn't cold enough for the glow system to operate.
Ah, factory lockers with correct indicator lights. Can't beat that.
I have expanded my fleet to 4 Cruisers and every one has them. 
Can you tell me what a shut down Buttfly is ?
Can you guys tell me what and where the shut down Buttfly is located ?
It's under here.
David*BJ70
Looking forward to reach the end of the world
Not helping so much to this thread, but I want to say I store my 12HT Cruiser for the winter and the glow screen is unplug due to a relay problem.
Let's say what you can expect from a healthy 12HT without glow screen when it cold outside : In late November, I made a last back country road adventure and the temperature went to -15°C (5°F) overnight and the engine started on the first key turn. For the first 30 seconds (+/-), it run rather roughly and puff white smoke but it start… which it surprise me. I thought I had to turn the key more than once.
Let's say what you can expect from a healthy 12HT without glow screen when it cold outside : In late November, I made a last back country road adventure and the temperature went to -15°C (5°F) overnight and the engine started on the first key turn. For the first 30 seconds (+/-), it run rather roughly and puff white smoke but it start… which it surprise me. I thought I had to turn the key more than once.
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This is a great idea in the process of elimination. It's been a while since I played with a 12HT but pretty sure it's set up the same as the 13BT: If you pull the vacuum line going to the shutdown pot the butterfly valve should default to the open position. Plug the end of the vacuum line so the system will build vacuum for the brake and clutch boosters. I had to do this with my 13BT this last summer to get back to the shop and replace the VSV after it decided to fail one day in traffic at a stop light. Also did this last year with a buddies BJ74 during the middle of a trip in Utah as his VSV starting randomly shutting down the engine on a trail. To shut the engine down close the butterfly valve manually or push the fuel lever on the side of the injection pump to shut off the fuel.
hth's
gb
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CenTXFJ60
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- #40
traveling for work but plan to test this when I get back. Early on before I wired in the VSV I ran an open system. Just used a vac line from the butterfly and one from the alternator and kept them in the cab. Touched them together to shut down. So the other morning I’m pretty sure I unplug the vac line from the diaphragm controlling the butterfly and there was no change in starting. Will confirm with another test. Here’s a pic of my original shut down system (a bit ghetto). Still thinking of adding a vacuum lever/dial type switch inside my cab and deleting the VSV. I had a similar situation last summer doing 75MPH way out in West TX and the motor shut down. By the time I coasted to a stop it dawned on me the VSV had to be the culprit.
