LJ78 2lte intermittent orange management light

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Hi all.
First newbie post.

I purchased a LJ78 last year and am finally getting it on the road properly after a lot of work.(Mainly to the body)


Jeep drives pretty well however I have an intermittent orange management light.
When this light is activated the turbo(green light) won't work and the jeep is really down on what little power it has.
Both light active when ignition is turned and both then go off after starting.
However after warming up at idle or a very short drive the orange light will come on and the jeep will have no power
The turbo light will come on sometimes while driving and it drives fine however the orange light tends to come back on when I come off the throttle, say coming to a stop or slowing and stays on.


I've checked the vacuum hoses for loose connections and can't find any or cracked ones


Also when I'm driving I can hear what sounds like a loss or release of pressure type noise from the engine bay, not sure if it's connected.
I've checked the troubleshooting as per manual provided by GTSSportCoupe and when the orange light comes on in this manner or sequence it's a faulty HIGH Pressure switch?? I can't seem to find this part or where it might be located in the vehicle.


Any help greatly appreciated 👍
 
You should probably use jumper to check the engine error codes. Theres a few thread here about that (just search).

When I had the engine light problem you describe, it was because I had the timing belt one tooth out, and the ECU could not achieve the proper injection timing at idle. This would turn on my check engine light, and it would also rattle a lot (in my case it was advanced). So if you did timing belt recently (or had it off), this could be the issue. It's an easy mistake to make.

Cheers!
 
You should probably use jumper to check the engine error codes. Theres a few thread here about that (just search).

When I had the engine light problem you describe, it was because I had the timing belt one tooth out, and the ECU could not achieve the proper injection timing at idle. This would turn on my check engine light, and it would also rattle a lot (in my case it was advanced). So if you did timing belt recently (or had it off), this could be the issue. It's an easy mistake to make.

Cheers!
Thanks for reply.
Yes I had the belt done recently however I had this checked as I thought the same thing. Could this cause the intermittent light? Or would bmit stay on all the time if it was a tooth off?

It's showing Fault code number 12 which could be a few different problems from what I can see.
problems?
 
Ah, okay, maybe another injection pump issue then; your issues sounds different than the one I had.

Sometimes sediment in the bottom of pump prevents the injection advance working properly (its a hydraulic mechanism). Some folks have removed the timing control valve, rinsed pump and had issue go away. Lots of work obviously.
 
Ah, okay, maybe another injection pump issue then; your issues sounds different than the one I had.

Sometimes sediment in the bottom of pump prevents the injection advance working properly (its a hydraulic mechanism). Some folks have removed the timing control valve, rinsed pump and had issue go away. Lots of work obviously.
Ok brilliant. Thanks for advice
 
Ah, okay, maybe another injection pump issue then; your issues sounds different than the one I had.

Sometimes sediment in the bottom of pump prevents the injection advance working properly (its a hydraulic mechanism). Some folks have removed the timing control valve, rinsed pump and had issue go away. Lots of work obviously.
Question for you.
Is there a mark on the 2lte pump for alignment when fitting?
I cant find anything on this particular pump for fitting but have read other Toyota when out of alignment cause similar problems due to this issue.

The head has been done previously at some stage so I'm just wondering was the pump removed as well at some stage previously and not fitted perfectly
 
Question for you.
Is there a mark on the 2lte pump for alignment when fitting?
I cant find anything on this particular pump for fitting but have read other Toyota when out of alignment cause similar problems due to this issue.

The head has been done previously at some stage so I'm just wondering was the pump removed as well at some stage previously and not fitted perfectly

Yes, there are lines, but they're not super critical. If the lines are even remotely aligned, and timing belt right, computer does the rest. There is a timing sensor in the pump, and a crank sensor on engine. Computer uses those two to adjust timing appropriately. Error usually comes if it can't achieve the timing it wants. This could be install error of pump or timing belt, it could be damaged timing control valve (thing that adjusts timing in bottom of pump), or maybe an issues in the timing pickup sensor (connector on top of pump).
 
Yes, there are lines, but they're not super critical. If the lines are even remotely aligned, and timing belt right, computer does the rest. There is a timing sensor in the pump, and a crank sensor on engine. Computer uses those two to adjust timing appropriately. Error usually comes if it can't achieve the timing it wants. This could be install error of pump or timing belt, it could be damaged timing control valve (thing that adjusts timing in bottom of pump), or maybe an issues in the timing pickup sensor (connector on top of pump).
Thanks again
 
I've searched for air leaks in the vacuum system and engine in general and found one. It seems to be missing the vacuum switching valve part number 9091012097. This is where the air is leaking.


From my searching for replacement part it seems to be discontinued everywhere. Would a similar part replace this one from a similar Toyota engine?


Do you think this could cause the intermittent engine mgt light. Lately the jeep has also cut out or stalled upon coming to a stop at light or was about to stall before I gave it some gas with black smoke because of very low poor idle.

IMG_20241218_133202.jpg
 
You just gotta do some emissions delete. Get rid of all that crap. You just need one boost line from intake to boost sensor. And also vacuum supply from vacuum pump on alternator to 4x4 VSVs (and brake booster). Thats it. That said, getting rid of emissions requires getting rid of throttle plate. This is all a huge favor to your motor though. These systems just suffocate these poor motors.
 
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You just gotta do some emissions delete. Get rid of all that crap. You just need one boost line from intake to boost sensor. And also vacuum supply from vacuum pump on alternator to 4x4 VSVs. Thats it. That said, getting rid of emissions requires getting rid of throttle plate. This is all a huge favor to your motor though. These systems just suffocate these poor motors.
I'll try and tackle this over the Christmas break.
Thanks for advice
 
You should probably use jumper to check the engine error codes. Theres a few thread here about that (just search).

When I had the engine light problem you describe, it was because I had the timing belt one tooth out, and the ECU could not achieve the proper injection timing at idle. This would turn on my check engine light, and it would also rattle a lot (in my case it was advanced). So if you did timing belt recently (or had it off), this could be the issue. It's an easy mistake to make.

Cheers!
I had the exact same symptom's. I received codes 11, 12 and 13, pointing towards the crank case sensor. One of the connecting wires to the sensor was all but gone. I soldered it back together and the issue disappeared.
You can easily reach the sensor from inside the left fender, after removing the wheel. I damaged the connector itself: I guess after 30 years the plastic gets brittle...
 
I had the exact same symptom's. I received codes 11, 12 and 13, pointing towards the crank case sensor. One of the connecting wires to the sensor was all but gone. I soldered it back together and the issue disappeared.
You can easily reach the sensor from inside the left fender, after removing the wheel. I damaged the connector itself: I guess after 30 years the plastic gets brittle...
Excellent. Thanks for the advice I'll check this as well and let u guys know
 

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