98 Toyota Prado duel fuel check engine light frustration.

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nucopia

nucopia

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issue with my 98 5vz-fe dual fuel . First fault code was only Code 55 (no signal to ecu for crank revolutions between 1800-5600rpm- *open short in knock sensor circuit*knock sensor may be loose *ecu) replaced both knock sensors with new units also replaced bottom harness and did continuity checks from top hatness to escu no problem with wiring , next replaced ECU. Still the same . Did another codes check, same 55 code came back .
After replacing with two new knock sensors plus replaced the bottom harness with a new unit from Japan, and replaced the ECU. I now still have the old 55 code ??
Car drives ok but once it warms up the check engine light still comes on after temp gage moves to normal running temp and revs hit around 3,000rpm whilst driving. If i stop and turn off the engine and start up again the light stays off as long as i dont drive and rev over 3,000rpms. I tried putting two bottles of lifter quiet in over the weekend and that helped slightly with the lifter noise but has not resolved the other issues with the check engine light. Fuel economy is crap and it runs ok until i need to drive on any moderate to steep grade, when it has next to no power.
Have a very good mate that is an engine rebuilder who is keen to help me solve this problem. But we just need some direction in what could be the cause ... We have done new knock sensors new harness, wiring harness tested and replaced ECU ...
Put up a post on the pradopoint forum which is dedicated to landcruiser prado's etc and after almost 12 months not a single reply from any member on that forum.
So I hope some one on here can clue us in on what next to look at, for solving the issue.
Cheers !
 
Have you tried changing the temp the idle air control valve?
Did a bit of digging for you and found a diesel with similar prob a few years back, turned out this sensor was the culprit. He had a diff error code coming up but same symptoms as yours - poor fuel economy and next to no power.
Hope this fixes your woes, and hope it doeant happen to my 90 series too!

Cheers,
TGW.
 
Did you disconnect the battery to reset the ecu and try again?

The first thing we have to try is to isolate the machine and restart to see if the problem goes away with the machinery at work.

Cheers

Doug
 
OHno nuc :eek: ...what have you done :eek: ...I'm not a Toyo tech but know Toyo's enough so....................................Q&A time :p
First things first your looking in the wrong area.........if a knock sensor was faulty would create constant pinging under most load so was probably only logging a fault
Because it's duelfuel it make's it sort of easier but maybe not :lol: :p
You've said it revs up to 3000 rpm when hot? yes?...does it do it on LPG as well as peto?
Think your overlooking a mechanical issue...possible air leak or LP or fuel problem.....
Check if it does it on both fuels?
When the light is on is when it's hot hey? @ 3000 rpm load it up on a hill...does it ping and check both fuels?
Does the brakes feel like a rock?....could be a few things along the airleak side.....but does it look like it's overfueling....
could be a fuel blockage overpressureing the injectors ...fuel pressure tester hooked up while driving ;) mine sits under the wiperarm so I can see while test driving :eek:
People on Motor forms are just enthuisiasts so don't expect any real knowledge unless it's a Ford forum :lol: :p
So............ 8)
edit...... what LP system? :p
 
no signal to ecu for crank revolutions between 1800-5600rpm ................... once it warms up the check engine light still comes on after temp gage moves to normal running temp

Would say that you have a sensor about to pack up (crank or cam if it has both ) as they usually play up more when they get hot in early stages of failing. If you can get to it wait till it plays up then pour a bottle of water on it and take for another drive quickly .
As B5 has suggested at least see if it is common on both fuels so you can at least cut your fault down to the cause being fuel or electrical. Would also explain the no power as when it drops the signal would default into limp mode and usually backs the timing off :eek:
Just had an after thought ................... could also be excessive slack in the cam belt or belt tensioner failing which allows the camshaft to float which will trigger fault light also as ecu see's it as cam going out of timing - phase. How long since cam belt has been serviced ?
 
Thanks TGW
Will look into that one cheers mate!
gday Rock Hunter
Yeah mate had the battery disconected over night a while back and it made no difference.
Still comes up with check engine light same fault code 55.
 
B5MECH said:
OHno nuc :eek: ...what have you done :eek: ...I'm not a Toyo tech but know Toyo's enough so....................................Q&A time :p
First things first your looking in the wrong area.........if a knock sensor was faulty would create constant pinging under most load so was probably only logging a fault
Because it's duelfuel it make's it sort of easier but maybe not :lol: :p
You've said it revs up to 3000 rpm when hot? yes?...does it do it on LPG as well as peto?
Yep same symptoms if i drive it on LPG or petrol ..neither makes a difference ...
Think your overlooking a mechanical issue...possible air leak or LP or fuel problem.....
Answer
Yep i might get the fuel pump checked an the fuel filter for blocks ..

Check if it does it on both fuels?
Answer
Yes on both LPG and petrol..

When the light is on is when it's hot hey? @ 3000 rpm load it up on a hill...does it ping and check both fuels?
Answer
Yep first start , once the temp reaches normal running temp and normal driving on both fuels its the same..

Does the brakes feel like a rock?....could be a few things along the airleak side.....but does it look like it's overfueling....
answer
Brakes are normal changed brake pads a few month back no issies there.
What do you mean over fueling ?
could be a fuel blockage overpressureing the injectors ...fuel pressure tester hooked up while driving ;) mine sits under the wiperarm so I can see while test driving :eek:
Answer
Ok again will check fuel pump and fuel filter see if either. Have an issue..
People on Motor forms are just enthuisiasts so don't expect any real knowledge unless it's a Ford forum :lol: :p
So............ 8)
edit...... what LP system?
Answer
OMVL R90/E made in Italy by REG
http://www.vlandgas.com.au/index.php?productID=678
:p
Click to expand...
 
Bogger said:
no signal to ecu for crank revolutions between 1800-5600rpm ................... once it warms up the check engine light still comes on after temp gage moves to normal running temp

Would say that you have a sensor about to pack up (crank or cam if it has both ) as they usually play up more when they get hot in early stages of failing.
Answer..

Will see if the mate can help me check the crank and cam sensors ..

If you can get to it wait till it plays up then pour a bottle of water on it and take for another drive quickly .
As B5 has suggested at least see if it is common on both fuels so you can at least cut your fault down to the cause being fuel or electrical. Would also explain the no power as when it drops the signal would default into limp mode and usually backs the timing off :eek:
Answer
yep as soon as the check engine light comes on it goes into limp mode..

Does it using LPG or petrol..
Just had an after thought ................... could also be excessive slack in the cam belt or belt tensioner failing which allows the camshaft to float which will trigger fault light also as ecu see's it as cam going out of timing - phase. How long since cam belt has been serviced ?
Answer ..
Not sure could have been about 4 years ago (transmission was done in 2011) will look into the cam belt and tensioner and see if thats an issue
Click to expand...
:Y:
 
I think I'm mis reading..........is the light on all the time? can it be cleared and stays away til it gets hot?
The brakes I meant could be the booster diaphragm cracked :lol: AKA airleak...could be a air bypass valve, inlet gasket/o'ring as well

Quote
issue with my 98 5vz-fe dual fuel . First fault code was only Code 55 (no signal to ecu for crank revolutions between 1800-5600rpm- *open short in knock sensor circuit*knock sensor may be loose *ecu) replaced both knock sensors with new units also replaced bottom harness and did continuity checks from top hatness to escu no problem with wiring , next replaced ECU. Still the same . Did another codes check, same 55 code came back .

Did you replace the crank sensor or not?....or have you only replaced a knock sensor?
Bogger wrote;
no signal to ecu for crank revolutions between 1800-5600rpm ................... once it warms up the check engine light still comes on after temp gage moves to normal running temp
?? :Y:
 
B5MECH said:
I think I'm mis reading..........is the light on all the time? can it be cleared and stays away til it gets hot?
The brakes I meant could be the booster diaphragm cracked :lol: AKA airleak...could be a air bypass valve, inlet gasket/o'ring as well

Quote
issue with my 98 5vz-fe dual fuel . First fault code was only Code 55 (no signal to ecu for crank revolutions between 1800-5600rpm- *open short in knock sensor circuit*knock sensor may be loose *ecu) replaced both knock sensors with new units also replaced bottom harness and did continuity checks from top hatness to escu no problem with wiring , next replaced ECU. Still the same . Did another codes check, same 55 code came back .

Did you replace the crank sensor or not?....or have you only replaced a knock sensor?
Bogger wrote;
no signal to ecu for crank revolutions between 1800-5600rpm ................... once it warms up the check engine light still comes on after temp gage moves to normal running temp
?? :Y:
Click to expand...
When I first start the motor and drive , the light is off . When the temp raises to normal and the motor reves over 3,000 the light comes on and it goes into limp mode. If I stop the motor and restart , the light stays off until I again hit 3,000 rpms then on goes the light and into limp mode.
Have not replaced crank sensor .. Only both knock sensors wiring harness and ECU
 
The fault code for no sugnal to ecu for crank revolution between 1800-5600 was rectified ages ago when we reset the ecu by disconecting battery. It cleared that particlular fault code..
The one that remained was fault code no 55 ...open or short in knock sensor circuit , knock censor may be loose, or ECU ..
 
Are you certain 55 is the knock? not crank like Bogger stated?
Does it missfire/ backfire or just loose power

Before the following....... when it's hot if you Ignition off / ignition on it's still there hey

Al right this is what I'd do....It's consistent on both fuels so......clear code...check it's gone.......drive til it comes on ......gota be persistant :lol:
Rescan...still 55 yes?....hmm...to catch the crank sensor out you need to log live data while the problem is present but try this....
But 55's the knock...I know...but when an engine's timing is out it'll ping or knock and that could be why that code is thrown
I don't think I've ever seen a crank sensor throw a crank sensor code on running engines only non start vehicles

Get it hot........... problem present and spray the crank sensor with freeze spray and see if it clears up ;)
If it clears up ....... finger pointed
Limp mode makes me think more sensor than air leak but a hot engine and a massive air leak could throw a knock code and if bad enough could opt to limp mode
 
B5MECH said:
Are you certain 55 in the knock? not crank like Bogger stated?
Does it missfire/ backfire or just loose power

Before the following....... when it's hot if you Ignition off / ignition on it's still there hey

Al right this is what I'd do....It's consistent on both fuels so......clear code...check it's gone.......drive til it comes on ......gota be persistant :lol:
Rescan...still 55 yes?....hmm...to catch the crank sensor out you need to log live data while the problem is present but try this....
But 55's the knock...I know...but when an engine's timing is out it'll ping or knock and that could be why that code is thrown
I don't think I've ever seen a crank sensor throw a crank sensor code on running engines only non start vehicles

Get it hot........... problem present and spray the crank sensor with freeze spray and see if it clears up ;)
If it clears up ....... finger pointed
Limp mode makes me think more sensor than air leak but a hot engine and a massive air leak could throw a knock code and if bad enough could opt to limp mode
Click to expand...

Yep fault code is No 55 knock sensor.

If I ignition off and then on again, the light turns off and does not come on until I drive it up to say 60kmh or 2500-3000 rpms.

Ok will try your suggestion , clear code , drive till light comes on and check the code.
Will,get it hot turn off motor then spray the crank sensor, drive it and see if check engine light comes on.
:Y:
 
They should have banned all tech advances after they made the xb coupe. That was the pinnacle I don't give a stuff what anyone says.
 
If it comes to a vacuum test ask your engine guy if he has a vacuum gauge...not pump....it shows optimum vacuum to timing issues to air leak :Y:
I use one alot :cool: :Y: helps tuning and also canceling out other issues...
Hook up and drive until problem starts....... noting vacuum changes ;) ...he'll show how to set it up and read it :cool: :Y:
It could also help with the sensor as it shows incorrect timing vacuum if the freeze doesn't work...

Note :eek:
You need to do the freeze thing with the engine running...it will fix or not
Ign on / off resets the computer so it will throw confusion :rolleyes:
I think in that model 20 Ignition cycles should clear the DTC's
 
In mine I had a dificult problem check engine, alternator, and one other warning light. Turned out to be a conector for the rear lights on the bumper had disconected itself. So be warned it may not be as it looks. Ken.
 
ken2m said:
In mine I had a dificult problem check engine, alternator, and one other warning light. Turned out to be a conector for the rear lights on the bumper had disconected itself. So be warned it may not be as it looks. Ken.
Click to expand...
Thanks Ken
I will keep this in mind.
The thing is doing my head in trying to find the cause but Im keen to find it and fix it .
Process of elimination I guess.
 

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