Prado 95 series 1KZ-TE 3.0l high revving (1 Viewer)

[Cayman1738]

Hey everyone
I'm currently reviving my old Prado and I have been able to rebuild the engine. After putting everything together, when I start the car, it starts revving high without touching me doing anything. I suspected it was the fuel pump and I got another one and it still had the same issue. I have changed the spill valve as well, still the same. This issue is really disturbing me cause its the last thing before I can drive the car again. Anyone here who has any idea what I should do?

 

[KiwiBogan]

Hey mate, this sounds really odd. The first thing that comes to mind is "runaway diesel" which is where oil is making it's way into the combustion chamber resulting in a self perpetuating ignition situation. Turning off the key will not stop this. You have to stall the car buy putting it in a high gear and releasing the clutch. Or blocking the air intake into the engine.

If the key turns the engine off when it is over revving, then I would suspect maybe something to do with your throttle position sensor?

 

[Cayman1738]

Hey mate, this sounds really odd. The first thing that comes to mind is "runaway diesel" which is where oil is making it's way into the combustion chamber resulting in a self perpetuating ignition situation. Turning off the key will not stop this. You have to stall the car buy putting it in a high gear and releasing the clutch. Or blocking the air intake into the engine.

If the key turns the engine off when it is over revving, then I would suspect maybe something to do with your throttle position se

Hey KiwiBogan,
I first thought it was the throttle position sensor, I disconnected it and the was still high revving. I removed the fuel injectors and saw that 2 of them had some oil, ended up checking the pistons and saw that the piston rings were bring the oil into the chamber.
That also explained why it was removing clouds of dark white smoke when I start the engine. And the engine would turn off when I turn the key off

I'll keep you guys update on the progress

 

[KiwiBogan]

Hey KiwiBogan,
I first thought it was the throttle position sensor, I disconnected it and the was still high revving. I removed the fuel injectors and saw that 2 of them had some oil, ended up checking the pistons and saw that the piston rings were bring the oil into the chamber.
That also explained why it was removing clouds of dark white smoke when I start the engine. And the engine would turn off when I turn the key off

I'll keep you guys update on the progress

Ahh yes of course. It's when you removed the butterfly from the throttle body that the engine won't turn off during a runaway diesel situation.

I'm about to have my 1kz-te rebuilt due to the rings being knackered so have been experiencing oil in the combustion chamber but not that bad. Sounds like you needed to bore, hone and use oversized pistons during your rebuild maybe? Good luck! I'm about to rebuild my 1kz-te so I'm interested to hear how you get on.

 

[jasonMartins]

Dunno if it is worldwide but in Europe the 1KZ-TE has a throttle body like petrol engines... So my first guess would be that the throttle is not closing properly leading to a higher manifold pressure than normal...

Also check for wrong connected hoses so ambient air can enter the manifold

Reving high means more like a little higher than expected (less than 1500) or like 2500 rpm plus?

 

[pradontever]

Prado 95 series 1KZ-TE 3.0L Manual E12 Injector Pump 'Runway Diesel'​

Hi all,
I am new to the Forum.
I have read all threads posted regarding High Revving but my experience is different.
I have owned this Prado over the past seven years, service every 6 months she runs perfectly fine up until couple weeks ago.
Recently I have noticed that my Prado throttle is sticky when changing gears, meaning the throttle appears hesitant won't drop the RPM straight away after releasing the Accelerator to push the Clutch Peddle.
It would take about a second to a second and half for the RPM to drop.
This leads to the Runaway Diesel issue I am experiencing three times while driving over the last couple of weeks, very scary.
This happened after I changed mostly 3rd to 4th or even 5th gear.
The motor maxed out the RPM sending the vehicle speeding out control thick black smoke blowing out the exhaust pipe.
I have managed to shut down the engine as quick as I can by switching Off at the ignition and pressing the Off button on the Turbo Timer control panel.
This happened late at night on a four lanes empty road after I serviced the Throttle Body thinking it was the caused.
I safely pulled over to the far left slip lane out of traffic and thought I might have blown my engine because the engine was thumping sounds I heard just before I killed it.
Got out assessing the tail pipe, under vehicle and under the bonnet, no signs of oil leaks, felt a bit relieved.
Checked the engine oil dipstick and coolant, the levels are at the level I serviced it three months ago, still clean as it only get driven 7-10 days, little use.
I have tried restarting the motor several times, it turns over but it won't start and the battery is showing sign of getting weaker.
Let it rest for 40mins, start it up again and she's starts with thick white smoke blowing out the back tail pipe.
After about a minute and a half the tail pipe is cleared no smoke like it normally is, limped back to my mate workshop.
Switch it off, plugged in the scanner to scan for error code, turned key to ON position but not starting the engine. No error code were detected.
So I believe it is not oil in the cylinders problem otherwise it would be smoke blowing all the time, right.
I am thinking this may be electronics related issues like ECU, Injector Driver Module or Accelerator Sensor which this model have.
Does anyone out there have encounter this incident?
Can anyone shed light what causes this Runaway Diesel?
I welcome any comments.
Thanks in advance.

 

[KiwiBogan]

Sounds really odd man. I wonder if it's something to do with this thing that your accelerator pedal operates? I don't know much about it I'm afraid. Maybe check those plugs are seated properly in the sensor and check the wires aren't frayed or damaged at the back of the plugs.

Reading your post again, it does sound like over fuelling (with the black smoke). Possibly an issue with the spill control valve getting stuck open?

Have a read through this. Might be of use?

Interesting discovery on 1kz-te and 2lt-te fuel pumps.

This maybe common knowledge to most but thought I would share. Over the last year or so my 1kz-te engine had been reving occasionaly, at idle, between 400 and 800rpm. After going through the fuel system the problem still persisted. Finaly 1 month plus ago the fuse on the battery terminal...

forum.ih8mud.com

 

[pradontever]

Sounds really odd man. I wonder if it's something to do with this thing that your accelerator pedal operates? I don't know much about it I'm afraid. Maybe check those plugs are seated properly in the sensor and check the wires aren't frayed or damaged at the back of the plugs.

Reading your post again, it does sound like over fuelling (with the black smoke). Possibly an issue with the spill control valve getting stuck open?

Have a read through this. Might be of use?

Interesting discovery on 1kz-te and 2lt-te fuel pumps.

This maybe common knowledge to most but thought I would share. Over the last year or so my 1kz-te engine had been reving occasionaly, at idle, between 400 and 800rpm. After going through the fuel system the problem still persisted. Finaly 1 month plus ago the fuse on the battery terminal...

forum.ih8mud.com

View attachment 3551511

Thank you so much for replying.
I will check the Spill Control Valve when I am next over at my mate workshop, that's where she is atm.
Peddle Sensor photo is identical to mine.

 

[pradontever]

Thank you so much for replying.
I will check the Spill Control Valve when I am next over at my mate workshop, that's where she is atm.
Peddle Sensor photo is identical to mine.

 

[pradontever]

Hello,
I am back.
It wasn't the Spill Control Valve/Solenoid, I serviced while I am at it, it is working as it designed to.
It turns out I have serious diesel leak into the engine oil system.
Checked the oil dipstick, level was extremely high, thin and strong diesel smell.
My good mechanic friend concluded the injectors must be leaking badly flooding the combustion chambers then make it way to the oil sump over the two weeks. There's no other way diesel can get into the oil sump.
I have pulled out the old injectors, all were missing the small washer between the Top Hat and the injector nozzle.
My mechanic friend said, the missing washers are unlikely the caused the diesel leak.
Two of them looks pretty bad, I am waiting for feedback from injectors specialist where I have got them from on an exchanged deal.
Refer to attached photos of dirty injectors, 4x replacement injectors with red caps and Spill Control Valve/Solenoid condition after serviced for your review.
I have installed the reconditioned ones with genuine Denso nozzle.
So far so good, I am letting it all settled down for a while before revving it.
I'll keep you all posted in due course how it all goes.