Intermittent engine warning light

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

No it's not a electronic throttle I have a cable. I thought the electronic throttle was just for the common rail diesels.

[scottkz Senior Member Find all posts View Profile Close scottkz]

Ahh so you have a series 1 ..... That could explain the colour code difference
Electronic throttle come out in the series 2 90 aus never got series 1s unless they have been a grey import
My car has the electronic type

[scottkz Senior Member Find all posts View Profile Close scottkz]

the series 1 wiring diagram i have says red/black goes to the ECU and the blue wire goes to power....

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

That's a new piece of info for me didn't know there were series 1 and 2 prado. Mine is a 1998 European specs as it used to belong to someone in the Italian embassy in Egypt.

So just to double check I should find the red/black wire in the ECU and get a temp wire from it directly to the TCV and the green/white I should connect it directly to power from the battery?

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

the series 1 wiring diagram i have says red/black goes to the ECU and the blue wire goes to power....

Just checked and it says other way round I attached a pic

[scottkz Senior Member Find all posts View Profile Close scottkz]

Strange ! Conflicting info on the colours ! Might just have to get yours apart and look what colours you have !
Yeah series 2 90s have plastic headlights clear body tail lights different door trims for power window models

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

I have Red/Black and Green/White to the TCV. Below are the several trials I did and the conclusion.

1)Temp wire from ECU directly to TCV :

No change at all.

2)Give ground (-) directly to the body of the TCV sensor:

Engine sounds much better and no rattling till it hits 2500 RPM and it starts to rattle and unstable.

Any suggestions? I have a EGR sensor as it's European specs, can it be the one causing this ?

[scottkz Senior Member Find all posts View Profile Close scottkz]

Not sure how the egr sensor works on them we never got them .... I doubt it would have a effect on the running as its basically mechanical injection
I'd be putting power directly to the red/black on the tcv

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

Yes this is what I did direct power to the red/black wire and temp wire from ECU to green/white

[scottkz Senior Member Find all posts View Profile Close scottkz]

Hmm got me bugged then! Might be the insides if the injector pump
Maybe check all the earth points on the engine block

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

All earth connections checked! This car is driving me crazy and I'm sure it's going to be such a stupid small reason for all this

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

Ok another very weird symptoms is when I disconnect the crank sensor the engine doesn't die?! Any suggestions?

[scottkz Senior Member Find all posts View Profile Close scottkz]

Yeah that's normal... It goes into limp mode bassicly the engine runs on one preset fuel curve and uses none of the sensors it's so you can get home
You could probly change the crank sensor there the same for most early toyota diesels
Failing that I'd say something is broken inside the injector pump
A friend of mine had one fully rebuilt in Perth for about 1300$ that included fitting
He was getting a heap more ks to a tank after that it had to be rebuilt as it had the engine light come on an off randomly
This was on a 1kz surf witch has the same pump as the early 90 series Prados

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

I replaced the crank sensor, but still the same issue. My other concern is according to my knowledge there's a rev limiter when the RPM hits near the red line the engine should stall or something which doesn't happen in my case as well.

Anyone did a mechanical pump conversion just to avoid all these sensors? I did some reading and I know they use the Mitsubishi 4M40 mechanical pump. What about the 1KZ-T pump?

[khorrassany Junior Member Find all posts View Profile Close khorrassany]

By the way I'm doing temp wires for all sensors from the ECU and see how it will function. I have an extra wiring loom from a auto engine so I cut the plug of the ECU from it and will attach temp wires and keep you posted.