Help?! 80 series - engine not switching off... randoms

[frank rabbets]

Its described as "Electromagnetic Shutoff Valve". I therefore assume it must be some sort of solenoid. I've not heard of one failing. It would have to fail in the open position. I would think a spring closes the valve when electomagnetism is not on and therefore it would be foolproof especially if made by Bosh. When the engine runs on you could try cutting the electrical supply to the valve and the engine can't run on unless the valve is faulty.

As an aside, in the old days, petrol engines ran on due to hot carbon in the combustion chambers. The hot carbon acted as a sparking plug and petrol supply was maintained due to a mechanical pump run off the camshaft. Sometimes one would have to drop the clutch in gear to stop the engine.

 

[Dave_S]

Thanks Frank - will have to see if/when it happens again. To be honest other than a problem here, or the engine consuming its own engine oil (which seems unlikely), or with the ignition switch itself, I'm at a bit of a loss!

 

[Grimbo]

Its most likely one of two things ....

Andy hit the nail on the head with fused starter solenoid contacts ......the solenoid is a plunger and contacts the batt + one side and the starter supply the other ....the batt + contact erodes faster than the starter one and causes the solenoid plunger to tip sideways in the bore it travels in .......you can buy a kit from Toyota and it's worth doing anyway because at some point this will happen .... I've had both my 80's do this.....as with yours it will then "cure " itself for a while before sticking again and poss to such a degree the only way to stop the starter is disconnect the battery . They will start and then run with only a slight whirring noise ....it's only when you go to stop the engine it becomes apparent .......

Secondly the stop solenoid stuck in the run position.

This can happen but very rarely as it is spring assisted down , much more common failure of these is the reverse .......as in the engine will run for a period of time then just stop as though the key was turned off .
The stop solenoid is a little coil that when energised causes a magnetic field that pulls the little plunger inside up against a spring and holds it there .....key off and magnetic field gone so spring pushes plunger down and closes fuel delivery . Often as heat and age affect the electric coil they can become weak and as they heat up resistance changes and the strength of the magnetic field drops away allowing the plunger to drop so stopping the engine. This can be a pain to diagnose as a multi meter will show a good 12+ volts at the coil. It can often take 30+ mins of running before this happens and if left to cool down the vehicle will restart as though nothing wrong .
Easiest way to diagnose this fault is remove solenoid , remove plunger and refit solenoid.....now only stalling the vehicle will cause the engine to stop unless you have a fuel problem .

 

[IRLGW]

I know of a guy with an 80 running on bio diesel. eventually it ate the seals on the fuel pump and it leaked fuel into the sump and the engine started doing that before it took off one day and he was very lucky to get it stopped. He got a turbo recon and it persisted which is how the pump was diagnosed.

 

[Dave_S]

Cheers Grimbo. Worth more investigation then.

We've never run bio so I think we're safe on that count IRLGW.

 

[moggy1968]

Landrover turbo diesels of old used to blow oil back up into the air filter, eventually that would get enough that the engine would start to combust on this after shutting down, although this was characterised by the revs increasing uncontrollably until the engine expired. Only way to stop it was cover the air filter or stall the engine.

 

[AndycruiserguyLomas]

Its most likely one of two things ....

Andy hit the nail on the head with fused starter solenoid contacts ......the solenoid is a plunger and contacts the batt + one side and the starter supply the other ....the batt + contact erodes faster than the starter one and causes the solenoid plunger to tip sideways in the bore it travels in .......you can buy a kit from Toyota and it's worth doing anyway because at some point this will happen .... I've had both my 80's do this.....as with yours it will then "cure " itself for a while before sticking again and poss to such a degree the only way to stop the starter is disconnect the battery . They will start and then run with only a slight whirring noise ....it's only when you go to stop the engine it becomes apparent .......

This has happened to me twice in the last 21 years I have owned 80's and can strike at any time. The first time the 80 was only 4 years old (in 1999) with 50k on it. I wondered what was going on as I'd only moved about 50 yards ( putting it in the garage) and when switching off the engine was still turning.It took me a good half minute to figure out what was actually happening and turning the key to start a couple of times disengaged it. I then didn't use it again till I'd replaced the contacts which obviously cured the problem but the starter was always a little noisier after that.
The second time was on my present 97 80 a couple of years ago but I instantly knew the problem and swapped the starter for a nearly new one off the "spares" truck.

This might not be your problem Dave but if it was me I'd have the starter off and check the contacts anyway. Fuel system wise these are pretty bullet proof, with all the ones I've had and run ( and passed onto other members) never had to touch any part or mess about with valves, solenoids or the like. Its always better to look for the simpler explanations than looking too "in depth" as 99% of the time its a simple solution.

 

[AndycruiserguyLomas]

Landrover turbo diesels of old used to blow oil back up into the air filter, eventually that would get enough that the engine would start to combust on this after shutting down, although this was characterised by the revs increasing uncontrollably until the engine expired. Only way to stop it was cover the air filter or stall the engine.

Apples and pears Andy, I've never seen ( or heard of) a 1HD-T being so worn out that that would happen. The 60 series engine I rebuilt with non existent piston rings hadn't even contaminated the air filter at all.

 

[Dave_S]

Cheers guys. The main reason I didn't think it would be the starter is that I'm pretty sure Jan would have spotted the noise.. but of course as I wasn't there and didn't hear it, I can't swear to that. Guess I'll be looking at the starter over the weekend. Thanks.

 

[frank rabbets]

I get the feeling Jan heard the engine cranking and not actually running as with key turned off it could not run unless faulty valve.

 

[richrock]

Mine did something similar, wouldn't stop one day then was fine for ages. A few months later it did it again and didn't stop until the starter motor had burned out itself and the 12/24v relay.

 

[moggy1968]

Apples and pears Andy, I've never seen ( or heard of) a 1HD-T being so worn out that that would happen. The 60 series engine I rebuilt with non existent piston rings hadn't even contaminated the air filter at all.

I think you mean rotten apples and a peach

 

[AndycruiserguyLomas]

I think you mean rotten apples and a peach

Ha, yes I'll go with that Andy.

 

[Dave_S]

So... truck did it again today, apparently, and after a bit of chat the starter motor idea is sounding more plausible (so apologies for doubting anyone previously!). Anyway, guess I'll be pulling the starter at the weekend and having a look-see. Joy...

 

[Dave_S]

Update... life got in the way and I completely forgot about this, as the truck "fixed" itself again... until today. Yup - definitely the starter jamming on this time, so I know what we need to do now! Does anyone have a link to the required solenoid rebuild kit please? I'll start trawling the web, but hoped one of you nice people would have the answer at your fingertips... Thanks guys.

 

[Dave_S]

Oh... might have answered my own question... this one?

https://www.roughtrax4x4.com/genuine-toyota-starter-solenoid-repair-kit.html

 

[StarCruiser]

That one has the basic size contacts. Have a chat with Mike at Robson and Francis, he has got me an upgraded set in the past which are around twice the size, two semi circles and a plunger.

Apology accepted BTW.

 

[Dave_S]

Cheers SC, appreciated. Will give them a call in the morning, thanks.

 

[mettisse]

Andy - not sure I follow - the truck wouldn't switch off, when running - not sure how the starter contacts would have any bearing on this. Am I missing something?

CG and go - yeah - weird... and as is often the case I can't get it to duplicate the problem now - its starting and stopping normally, no weird noises or anything.

If anyone can point me at the cut off relay, I'll take a look at that - just don't know where the blasted thing is, as the diagram I found on line for this is completely unhelpful!

Cheers guys

Within the last 6 weeks I’ve had to replace the starter motor with the problem of similar description, the funny noise was the starter trying successfully trying restart the engine, and to stop it, I disconnected the battery, if you have the correct spanner handy for an emergency to stop the noise/ engine, and save yourself anxiety, because if it is the starter, it will happen again. I hope that your solution is easier and cheaper than mine. Best regards, Bill Westley

 

[Dave_S]

As an aside, looking at the solenoid rebuild prices, I wonder whether I would be better simply buying another (new) starter motor? Anyone with experience of aftermarket starters for the 4.2 24v?