12ht motor cutting out (1 Viewer)

[webby61]

Hi All,
I rebuilt my 12ht HJ61 motor 2 years ago, plus injector pump and turbo.
Around 8mths ago whilst driving down highway, the motor cuts out.
Replaced alternator/battery/ all fusible links/earths etc to resolve problem.
Then month or so later it does it again, have had auto elect out.
replaced wiring harness in steering column, relays etc.
When it shuts down, it may take 8-10 cranks for motor to restart, or sometime it take longer.
Fuel not the issue, as once it starts it bellows out black smoke from excess fuel.
Has new vaccum pump.
Injectors and pump re kitted, new fuel filters.
its driving me round the bend, as soon as it shut down I call the auto elect so he can see for himself, but
usually by the time he get there it will restart.
regards

 

[Crick60]

Initially I suspect the VSV or more specifically the coil on the vsv, maybe try change it out with the 4wd engage or idle up vsv. It's a bit fiddley but a pretty simple job.

 

[webby61]

I'll plead ignorant , where are the coils in the vsv, and how vsv are on these engines.

 

[roscoFJ73]

VSV = vacuum solenoid valve.It shuts down the airflow into the engine when you turn the ignition to off.

https://forum.ih8mud.com/attachments/vacuumswitchvalve-jpg.824820/

Im not 100% sure that is the problem. I think if it wasnt working you would have trouble shutting the engine down ,but its worth having a look to make sure wiring and vacuum tubes are in place.

 

[Crick60]

The coil on the vsv is always on while the motor is on or in the on position so when you key to off or ignition it deenergises the coil, re routing the air and kills the motor. If that coil or plug or wire connection is poor or faulty it could be a problem.
I think toyota over rated the coil to deal with it being on all the time and to minimise heat and over complication with timing and relay circuits.

Like I said its a nice easy starting place if you can get your head around how to change the air for one of the other valves, you get usually get one from a wrecker or spares place for near nothing. All you have to do is remove the filter from the other style vsv and put a smaller tube in there and connect it up to one end and the other pole is used leaving one spare for the filter to go back on, it's a bit backyard but you figure out pretty quick if it's the problem.

Or next time it happens you can test the vsv by either get close to it and listen and touch the coil area for clicking or by taking a hose if and checking for vacuum or lack there of (check the FSM).