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1KZ-TE Goes Wild

Xena

New Member
Joined
Jul 14, 2016
Messages
32
Country Flag
philippines
Dear All,
Close to frustration, I am posting my engine problem here in hopes that someone has encountered this challenge and was able to solve the mystery.

I'm from the Philippines and a proud owner of a 1997 Land Cruiser Prado, a KZJ95, my daily drive to work and everywhere.
It is equipped with a 1KZ-TE engine and an auto transmission.

I am also surfing the net and all other forum groups for Prado's and Landcruisers and other diesel sites. But so far I have not found a solution.

Last October 23, after coming home from a 25km uneventful drive, I got off and let the engine nicely idle but then in about a minute of idling it suddenly went wild giving off black smoke very similar to that of a "diesel runaway". I ran back to the car and saw engine RPM was beyond red mark on the tach. I turned off ignition. I then tried to re-start the engine and as soon as it started, began screaming again and RPM went redline and super black smoke filled the street.

Initial inspection showed that wires #1 and #2 on the Turbo Pressure Sensor was cut. I re-soldered the wires following its color code, but problem still same.

Note that EGR was already removed a long time ago and thus the venturi butterfly/valve has long since been removed. VSV's already removed long time ago.

No ECU DTC displayed, no check engine lights . Tried disconnecting the individual sensors one at a time and do a test restart and engine check will show the corresponding disconnected sensor in error. This tells me DTC is working

Troubleshooting done as of this time

1. Replaced turbo pressure sensor with original new Toyota part
2. Swapped ECU with known good spare
3. Swapped TPS with known good spare
4. Inspected all ECU sensor wires and connectors using Fluke digital meter. Referred to a Prado Electrical and ECU diagram.
5. Performed voltage and resistance tests based on Toyota service manuals. Tested Engine Speed Sensor, Correction resistors, TPS, Water temp sensor, Crank Position sensor, Fuel Temp Sensor, Spill Control Valve, Timing Control Valve. SPV and TCV have correct resistance and clicks when voltage is applied.
6. Disabled Positive Crankcase vent system as I saw oil on the intake area. Note PCV passes thru an oil catch tank which is regularly emptied during 5k oil change.
7. Removed and cleaned intake manifold of any oil residue.
8. Removed and cleaned injector nozzle and glow plugs.
9. Performed cylinder purging of any oil that may be there. Only a little came out and exhaust ports didn't show oil and only carbon deposits
10. Replaced Turbo when I still saw oil in intake even after disabling PCV. No more oil after replacement and cylinder purging but engine still wild at start up. Turbo is now new and no more oil seen.
11. Cylinder purging is done via cranking the engine over and over with high pressure air being pumped into the intake valves and whatever air or oil inside are being spewed out from the exhaust, injector nozzle and glow plug ports
12. Replaced engine oil and filter and no significant oil reduction noticed. No excessive emission smoke noticed prior to failure.
13. Drained Injection pump and replaced fuel filter and switched fuel source from main tank to recently filled sub-tank
14. Removed spill valve and cleaned fuel filter under it.
15. Removed Fuel Temp Sensor and cleaned fuel filter.
16. Tried to let the engine run a little longer than start/off, maybe 30 seconds of redline. I was hoping that any oil residues would burn off. . . no luck here too

In all these actions only the smoke color changed from black to gray when a new turbo was installed but then engine still goes redline upon startup.

I have now removed the Injection pump and will send it to a good calibration center.

Hoping for your kind assistance, I shall be forever grateful.

Jim
 
Hi Jim and welcome to this most friendly forum. Sounds like you've replaced most of it already. I would have suggested Spill control valves as a first port of call, you clearly don't have a runaway as you can turn it off so that rules out anything engine oil related. So it must be fuel. Now that you've sent your injection pump away, as long as it is fully overhauled with new Spill control valves, I would be surprised if this does not cure the issue. This info is based on troubleshooting not actual experience of the same situation. Someone on here may have had the same issue and be able to be more specific. @Beau may have more info.
 
Malfunctioning spill control valve seems most likely to me , there's a cap on top of it you can pull to adjust fueling just yank it off with pliers (it slots back on) to reveal a 12mm lock nut holding a 6mm adjust nut , turn anti-clockwise to turn fuel down . If you need to turn it up again do it in very small increments or you will end up with a runaway engine :shifty:
 
The only time I've got the exact same problem you've described is when I turned the spill control valve adjustment (mentioned above by Shayne) too much. Screwed it in too much. You've already sent off the pump, but if you had it you could wind back out to reduce the fueling and see if this changes.

Alternatively, maybe the Spill control valve was internally blocked and wouldn't operate as normal causing the pump to drive in as much fuel as it allows. A correct spill control valve ohm reading wouldn't spot this. Good luck with the fix. Hopefully the high rev RPM's haven't done any damage. When I had the runaway engine, I'm sure it somehow chewed a glow plug tip at 5000RPM.
 
Star Cruiser,
Thank you so much for the welcome. I've actually been registered for some time now and have greatly enjoyed reading the coversations and valuable tips and resolution articles here. The forums made me keep my ride for a long time to come.
Yes, I too was left thinking that theres no other part but the spill valve. But then again resistance and voltage reactions checks out. Such a head scratcher
 
Have you checked if the oil level has risen after running the engine? Its a long shot but if the injector washers/seals have gone you may be getting diesel washing through to the sump, this can cause runaway also.
 
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Shayne and Beau,
Yes sirs ive tried the spv adjustment as well. Turned counter clock and stopped at 3 full turns but still same. Not even a hint of improvement. Turned again clockwise past the starting point but still same. I have to state though that i did not do any small increment turning even on the clockwise adjust. It was one full turn each time.
Thank you so much for your replies
In times of dire need, its such a relief to know that someone is out there to share their thoughts and experience
 
Trevor,
Yes sir, i have drained and measured engine oil levels at that point when I replaced turbo. A 5k oil change was performed 2 months ago and there was very little change, if any. I also replace with new oil when i restarted after turbo replace. When i took out the injector nozzles as part of isolation, i also replaced the nozzle seats and washers with new ones
 
It is possible to turn a seal when refitting injectors which could lead to this but in fairness I would expect to either see a level change in oil or at the very least smell diesel contamination in the sump oil if this were the case. So it sounds like the problem is elsewhere.
 
Trevor,
Yes sit, I also thought about this possibility that is why I tried to eliminate all possible sources of uncontrolled fuel be it via the crankcase blowby gasses or the turbine oil seals which led me to get a brand new turbo charger. Cold compression tests also gave indications that piston rings were in order. Valves and seals were also ok as per compression and the fact that I had a cylinder head change 3 years back because of that nasty headcrack which the KZ is famous for. I even tried to observe the intake valve moving by starting the engine with the intake manifold removed..... no oil coming down the valve shafts
 
… ive tried the spv adjustment as well. Turned counter clock and stopped at 3 full turns but still same. Not even a hint of improvement. Turned again clockwise past the starting point but still same. I have to state though that i did not do any small increment turning even on the clockwise adjust. It was one full turn each time.

Then there's your problem Xena. If you've adjusted it and it made no difference then for some reason fuel is getting past it and not being affected by your adjustments. This could be that it has become stuck or a seal has failed somewhere inside. I'm confident your pump if properly serviced and tested, will return and your problem will be gone. It's not going to be sump oil related because you turned it off with the key.
 
StarCruiser, Shayne and Beau thinks its an SPV failure too.
Fingers crossed.

Jim
 
I've turned my SPV down to the stop , about 3 full turns , and was surprised to find it was still perfectly driveable , The real difference was that it ran out of go in the higher revs - feels almost like the clutch slipping .

If you can't adjust it then its likely shot . The only other thing i can think of is low boost pressure either due to a poorly adjusted wastegate actuator or an air leak in the intake , 14psi is max boost (around 7 is normal) , fuel can't burn without air so an adequate amount of air is just as important as fuel .
 
I've turned my SPV down to the stop , about 3 full turns , and was surprised to find it was still perfectly driveable , The real difference was that it ran out of go in the higher revs - feels almost like the clutch slipping .

If you can't adjust it then its likely shot . The only other thing i can think of is low boost pressure either due to a poorly adjusted wastegate actuator or an air leak in the intake , 14psi is max boost (around 7 is normal) , fuel can't burn without air so an adequate amount of air is just as important as fuel .
And the black smoke would indicate an excess of fuel entering the cylinders. Seeingvas this happened when the vehicle was running and not being adjusted, I doubt it would be an adjustment issue, more something that has broken within the fuel delivery system (pump) rather than stuck, even. Maybe a spring has let go, as something has altered to let it suddenly behave as if the throttle is wide open. A governor spring perhaps or a seal that's let go.
 
Gents,
Your points are noted and well taken
Results from calibrators would be coming in about a day or two. I am so hoping to finally solve this enigma

Jim
 
I'm still waiting for final repairs tentatively completed by tomorrow
Spill Valve shall be replaced and the plunger will be machined with a new bushing, as per calibration shop.
I guess there's nothing much inside the IP and so I truly hope this fixes the problem.

As I was surfing the web for information, I came across a file for the IP Test Specifications, specifically for
VE4/12E2100RND013 Labeled as specifically used for Toyota Land Cruiser 1KZ-TE.

It states that the height of the SPV screw to be at 3.0-5.2 mm.
SPV Screw.JPG

Hoping this could be of help to those who might encounter this situation or question
 
I guess there's nothing much inside the IP and so I truly hope this fixes the problem.
They're noted as very reliable, so I guess you could say there's not much to go wrong but they are probably the most complex precision engineered part in your engine. It's imperative that no dirt whatsoever gets into any part of the pump or injection lines or injectors as one grain will cause serious wear and failure. Lines and ports should be immediately plugged or capped on removal to avoid contamination.
 
They're noted as very reliable, so I guess you could say there's not much to go wrong but they are probably the most complex precision engineered part in your engine. It's imperative that no dirt whatsoever gets into any part of the pump or injection lines or injectors as one grain will cause serious wear and failure. Lines and ports should be immediately plugged or capped on removal to avoid contamination.
Noted StarCruiser
 
At the mercy of the IP Calibration shop, they also want to replace the correction resistors which i've tested over n over to be good.... sigh.
 
These pumps aren't prone to failure so if its going into silly money i would like at buying a used replacement
 
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