LJ78 OD Limp Mode Issue

[Reedys]

Hi everyone,

I’ve had a read through a bunch of threads but I’m still not 100% sure what’s causing my limp-mode issue. I did see one post where a Toyota specialist fixed it by adding a new ground wire from the engine, but before I go chasing that I wanted to see if anyone has had the exact same symptoms.

My OD light starts flashing after I begin driving. It’s not a code flash sequence, it’s just a steady flash every few seconds.

Before this started, I noticed my shifts were feeling a bit clunky. I checked the ATF and found it was pretty low, but the colour still looked decent, so I topped it up rather than dropping the pan and doing a flush/service. But perhaps I should ??

I couldn’t find a working LJ78 manual link (all the old ones seem to be dead), but based on what I’ve read the correct procedure is to run the shifter from P down to 1, then back up to Neutral once the trans is fully warm.

After topping up the ATF, the clunkiness disappeared and the car stopped going into limp mode, at least for a bit. Now it’s inconsistent: sometimes it drives fine, and other times once it reaches temperature it drops back into limp mode again. It’s not consistent every drive, which is what’s confusing me, for example I went for a 20m drive last night fine no worries. Today I started the car and drove down the road going through the gears normally and then about 45s later it went into limp mode, holding revs below ~2,000 unless going down a hill in which it’ll maybe push closer to ~2,400.

I have slightly overfilled the ATF (image attached), so I’m wondering if that could be triggering the issue again. I’ve heard the A343F can be pretty sensitive to fluid level. I also topped the ATF up with Dex III premium mineral.

It’s pretty frustrating because it makes the car difficult to drive, and I don’t want to risk damaging the transmission.

Car: 1991 Landcruiser Prado
Trans: A343F
Motor: 2L-TE

Any advice or similar experiences would be greatly appreciated.

Thanks in advance.

-R

 

[Reedys]

Bumping here incase anyone has experienced anything similar and can point me in the right direction.

 

[Dprio34]

@Reedys , I’ve only had one other vehicle go into limp mode, and it was a dirty MAF sensor. I sprayed it down with Electronic Parts Cleaner, and that fixed the issue, and never had a problem since. Have you tried cleaning the MAP sensor (I believe there is one on 2L-TE)? Have you removed any of the emissions piping / EGR from the vehicle? That area in and around the Intake Manifold tends to get pretty gunked up. I would start with cleaning up that area, based on my limited experience of limp mode. I tend not to think it is from that slight overfill of trans fluid. Make sure to double check all the electrical connections and hoses are secure in that area as well.

 

[Reedys]

@Reedys , I’ve only had one other vehicle go into limp mode, and it was a dirty MAF sensor. I sprayed it down with Electronic Parts Cleaner, and that fixed the issue, and never had a problem since. Have you tried cleaning the MAP sensor (I believe there is one on 2L-TE)? Have you removed any of the emissions piping / EGR from the vehicle? That area in and around the Intake Manifold tends to get pretty gunked up. I would start with cleaning up that area, based on my limited experience of limp mode. I tend not to think it is from that slight overfill of trans fluid. Make sure to double check all the electrical connections and hoses are secure in that area as well.

Hey mate,

Thank you very much for the reply. I actually just recently cleaned out my intake manifold, was gunky but much nicer now as I recently replaced the turbo.

I did check my MAP sensor snd it seems quite normal, might be time for me to check all of the wiring to make sure it’s fine.

One thing I have noticed recently is it drives normal / unrestricted until the car reaches around 70°C and then it is constantly flashing the OD off light. Sometimes if I click overdrive on/off or hit the power button to enable and or vice versa, it can sometimes revert snd the car drives normal again for a while. Sometimes nothing I do can reset it, I just have to wait for it to cool down a little and try again.

Thanks,

 

[Dprio34]

@Reedys , you wrote 70C? Did you mean 70km/hr? Or do you have a aftermarket water temp gauge? I have an R151 and 2LT-2 so I don’t have experience w/r/t the OD &Power buttons. But it sounds like you are temporarily tricking the system somehow.

Water Temp of 70C is not much / very high. During the summer, it is quite common for my engine water temps to be at 100 C while EGT will be at 680C. I recently spoke with another Las Vegas LJ owner with 2LTE engine. His A/C will shutdown if the engine gets too hot. There is an AC cutout feature with your engine. However, his LJ with AOD did not go into limp mode.

You say, you cleaned up the intake, and are going to double check your vacuum hoses and electrical connections, but were you able to clean the area around the restrictor plate on the EGR system? It may be worth the investment to buy a new MAP sensor and try that as well. Hope you can get it sorted soon.

 

[Reedys]

@Reedys , you wrote 70C? Did you mean 70km/hr? Or do you have a aftermarket water temp gauge? I have an R151 and 2LT-2 so I don’t have experience w/r/t the OD &Power buttons. But it sounds like you are temporarily tricking the system somehow.

Water Temp of 70C is not much / very high. During the summer, it is quite common for my engine water temps to be at 100 C while EGT will be at 680C. I recently spoke with another Las Vegas LJ owner with 2LTE engine. His A/C will shutdown if the engine gets too hot. There is an AC cutout feature with your engine. However, his LJ with AOD did not go into limp mode.

You say, you cleaned up the intake, and are going to double check your vacuum hoses and electrical connections, but were you able to clean the area around the restrictor plate on the EGR system? It may be worth the investment to buy a new MAP sensor and try that as well. Hope you can get it sorted soon.

Hey,

Thank you, yes, I do have an aftermarket water temp gauge, sorry was referring to this. I also was supposed to write 90C/100C.. my bad.

Interesting that the AC shuts off when too hot, am yet to experience that. Quite surprised how electronically switched on these cars are.

Will try my best to source a new MAP sensor (not sure if anyone here has one, reach out if so), I didn't clean my EGR system, I should have.

Actually did notice today that my fuel filters bleed valve is leaking quite quickly, assuming it's fuel and not actually water as it took about 8s to start today and it's very warm out / glows are healthy. Hoping air in the fuel lines is my issue after all. I recently purchased a new bottom / top to my fuel filter, as well as the new fuel filter, but the bleed screw's O-ring was broken so I opted to put the old screw in, perhaps the o-ring on that is cooked.

Will try some new things, next will probably pull the ECU out to check on that.

I've also been told that loose wires to the crank sensor, trans speed sensor or shift solenoids can be causing this too. So have a few things to look over.

Kind regards,

-R

 

[Dprio34]

@Reedys , again, hopefully you get this sorted quickly. Sorry to hear about your leak on with the fuel filter. Should be easy enough to fix that. I can't believe no one else has chimed in on this thread. Someone has had to have a limp mode problem with their 2LTE. But anyway. I would double check all those hoses and connections, and give a good clean up to that area. Yes, there is a lot more going on with your engine than mine with that computer. I saw Ebay has quite a few MAP sensors for sale, but most are from China. Not sure about the quality, but maybe worth a shot / taking a chance for fifty bucks or so.

Just curious, what is your top speed in “limp mode?” Does the 2LTE have an annunciation for limp mode? Or are you just developing a lt less power?

At any rate, I believe this is the MAP sensor part number: 89421-60030 MAP Sensor Turbo Pressure Sensor Fits Toyota Hilux Surf Turbo Diesel or it could be 89421-60040. Please double check my work! Cheers!

 

[Reedys]

@Reedys , again, hopefully you get this sorted quickly. Sorry to hear about your leak on with the fuel filter. Should be easy enough to fix that. I can't believe no one else has chimed in on this thread. Someone has had to have a limp mode problem with their 2LTE. But anyway. I would double check all those hoses and connections, and give a good clean up to that area. Yes, there is a lot more going on with your engine than mine with that computer. I saw Ebay has quite a few MAP sensors for sale, but most are from China. Not sure about the quality, but maybe worth a shot / taking a chance for fifty bucks or so.

Just curious, what is your top speed in “limp mode?” Does the 2LTE have an annunciation for limp mode? Or are you just developing a lt less power?

At any rate, I believe this is the MAP sensor part number: 89421-60030 MAP Sensor Turbo Pressure Sensor Fits Toyota Hilux Surf Turbo Diesel or it could be 89421-60040. Please double check my work! Cheers!

​

View attachment 4034604

Not super sure on top speed, but it just hard limits the revs to around 2,200. If I happen to be rolling down a hill, it'll pickup enough revs to the point where the turbo will kick in and actually push it beyond. Definitely a loss of power in comparison to when it drives normally. Pretty sure it just doesn't push past 2nd gear.

At a guess, maybe around 50km/hr. I was under the impression that the flashing OD light / it not throwing a code meant it was in limp mode. I just had a look, I'm fairly sure the part number is: 89420-60030. Yeah unsure on the quality, but if I can't find any genuine MAPs I'll just have to opt out to an Ebay one.

I picked up some MAF cleaner today, so will delicately give the MAP a clean in the meantime.

Really appreciate your help, can't wait to finally get to the bottom of this.

Thanks!!

 

[Reedys]

Not super sure on top speed, but it just hard limits the revs to around 2,200. If I happen to be rolling down a hill, it'll pickup enough revs to the point where the turbo will kick in and actually push it beyond. Definitely a loss of power in comparison to when it drives normally. Pretty sure it just doesn't push past 2nd gear.

At a guess, maybe around 50km/hr. I was under the impression that the flashing OD light / it not throwing a code meant it was in limp mode. I just had a look, I'm fairly sure the part number is: 89420-60030. Yeah unsure on the quality, but if I can't find any genuine MAPs I'll just have to opt out to an Ebay one.

I picked up some MAF cleaner today, so will delicately give the MAP a clean in the meantime.

Really appreciate your help, can't wait to finally get to the bottom of this.

Thanks!!

Update, sprayed in the long nipple off the bottom of the MAP sensor with MAF cleaner. Car seems to run fine for around 15m, then went back into limp mode

Also replaced the bleed screw and the rubber o-rings on the screw. Car seems to start a little easier now. Hose off the bottom of the MAP sensor seems a bit old and ready for a replacement, will replace that while I’m at it.

Did find some OEM MAPs on eBay but for like $500…

 

[Reedys]

Not sure if relevant, pushed all 4 electric windows up at once and noticed the battery meter very close to the bottom of the white zone. I might need to look over the ground wire (apparently quite prone to rusting)

 

[Dprio34]

@Reedys , I'd go buy a long length of vacuum hose, and replace all of those hoses, if I were you. Also, I'd check your battery with a multimeter. While the vehicle is running you should have around 14v give or take, and with vehicle Off, the Battery voltage should read above 12.2v. If multimeter shows below 12v after sitting a while, It's probably time for a new battery. Replacing / Upgrading Battery to Chassis Ground cable and Engine to Chassis couldn't hurt things either. I think I'd roll the dice on an admittedly Chinese repro MAP sensor, rather than pay $500 for an advertised OEM MAP sensor. Lots of fake OEM parts on that platform.

Also, If you have several "lights" / annunciators flashing on your dash, that is usually indicative of the External Voltage Regulator going bad. They are cheap and available from the stealer. Are any other lights flashing other than OD light?

I am reconsidering what you described as "limp mode." Again, on another vehicle, not my LJ, I got a no joke limp mode. Vehicle would not accelerate past 10 miles per hour until I cleaned the MAF because the ECU directed as such. What you describe is something more like an intermittent power issue. You replaced your turbo recently. You said you cleaned your Intake. Are both of your hoses that connect the Turbo to "Intercooler" (I call it the crossover pipe) and Intercooler to Intake in good shape and tight? They are prone to cracking with age as well. Again keep us posted. Hope you get her fixed soon.

 

[Reedys]

@Reedys , I'd go buy a long length of vacuum hose, and replace all of those hoses, if I were you. Also, I'd check your battery with a multimeter. While the vehicle is running you should have around 14v give or take, and with vehicle Off, the Battery voltage should read above 12.2v. If multimeter shows below 12v after sitting a while, It's probably time for a new battery. Replacing / Upgrading Battery to Chassis Ground cable and Engine to Chassis couldn't hurt things either. I think I'd roll the dice on an admittedly Chinese repro MAP sensor, rather than pay $500 for an advertised OEM MAP sensor. Lots of fake OEM parts on that platform.

Also, If you have several "lights" / annunciators flashing on your dash, that is usually indicative of the External Voltage Regulator going bad. They are cheap and available from the stealer. Are any other lights flashing other than OD light?

I am reconsidering what you described as "limp mode." Again, on another vehicle, not my LJ, I got a no joke limp mode. Vehicle would not accelerate past 10 miles per hour until I cleaned the MAF because the ECU directed as such. What you describe is something more like an intermittent power issue. You replaced your turbo recently. You said you cleaned your Intake. Are both of your hoses that connect the Turbo to "Intercooler" (I call it the crossover pipe) and Intercooler to Intake in good shape and tight? They are prone to cracking with age as well. Again keep us posted. Hope you get her fixed soon.

Thank you,

Yep, have gone through and replaces all hoses besides 2. (Just in a tricky spot - kinda behind the throttle position sensor if I remember correctly).

Speaking of the TPS is that worthwhile replacing, looks perfectly fine, but not sure if that could be causing this?

Still having these issues, seems more common now, I will pull my ECU out tomorrow and look to see if theres any leaking, perhaps will need to take it to a shop as I've never dealt with that so truly not sure what I'm looking for.

On the other note, went ahead and replaced the belts, water pump, thermostat and housing. Had to bypass my heater tap as it was all starting to rust out and I pulled a hose off that lead to some of the metal pipe snapping. Going to leave that bypassed for now as it's near impossible to find a replacement...

Both the hoses coming off the turbo/crossover pipe are in good shape, no cracking there which is nice.

Feeling pretty defeat at the moment, even tried again today to use a paperclip to connect TE1 and E1 but still aren't getting any errors throw. Just to confirm I've done the procedure correctly, get the car warm and wait for the O/D light to flash (sometimes takes a while), turn it off, bridge TE1 + E1, turn the ignition on (engine off) and it should flash a code?

Once again, thank you for your help, would love to get to the bottom of this ASAP...... Just want to start driving this thing haha

Kind regards,
R

 

[Reedys]

Forgot to mention, no other lights on the dash are flashing on/off, it's just the O/D. It sometimes doesn't always flash at the moment the car starts to act weird, but will soon follow.

when the car is driving normal it has full power and drives well. But being capped to say gear 3, making it very hard to get going from a full stop.

I will be adding the chassis to transmission (probably the bell housing) ground cable tomorrow too as I'm not even sure I can see one on there from factory.

Ty

 

[Dprio34]

@Reedys , Ty, it is frustrating, but don't lose hope! I can't take credit for the following; I had to call a friend. From NAS90tdi, he recommended the following:

"OD light could be a misadjusted kick down cable making it hunt gears basically. Intermittent power could be several things. The very first thing to check is the 1/4" boost line from the intake to the fuel/boost sensor on the LH fender. If that is leaking it will essentially cut fuel because it sees less or no boost so it thinks it needs to cut fuel to match."

After checking the above, I can't remember, did you roll the dice on an aftermarket MAP sensor?

 

[Reedys]

@Reedys , Ty, it is frustrating, but don't lose hope! I can't take credit for the following; I had to call a friend. From NAS90tdi, he recommended the following:

"OD light could be a misadjusted kick down cable making it hunt gears basically. Intermittent power could be several things. The very first thing to check is the 1/4" boost line from the intake to the fuel/boost sensor on the LH fender. If that is leaking it will essentially cut fuel because it sees less or no boost so it thinks it needs to cut fuel to match."

After checking the above, I can't remember, did you roll the dice on an aftermarket MAP sensor?

Thank you!

I replaced the MAP sensor today without success, I also tried replacing the filter that runs off the end of the maps vacuum line, it was thinner both on the top nozzle and bottom nozzle. In the process I must’ve left the old (original) filter somewhere on the car and drove off so have now lost that proper filter, not sure if I can just bypass this or if it matters that this one is thinner? But it did seem to drive worse with this new filter…

Also to mention, most of the vacuum lines I’m running are either 3mm or 4mm inner diameter and then the hose out the bottom of the filter is closer to 5mm. I’ve attached a picture of the 5mm hose and the filter I’m running now instead.

Will pull the ECU out now, hopefully someone locally can repair it for me if it’s broken. Otherwise there seems to be a few new ones floating around for about A$1,750. Guess that doesn’t change the fact that the capacitors weren’t great.

Thanks,
R

 

[Reedys]

Pulled the ECU, everything actually looks in good condition can’t lie… was kinda hoping it was finally the solution to this problem.

 

[Reedys]

** forgot to reply fully, I haven’t checked the kickdown cable, however, I have replaced close to all of the vac lines in the engine bay. The vac line from the map sensor (boost line) is new and in good condition.

 

[Reedys]

Bridged E1 & TE1 again today just to make sure and it just gave a solid flash.

Flash…. Flash…. Flash (roughly 4-5s gaps between).

I did get to drive around for about 5 or so minutes at regular power before the OD light started flashing & loss of power began.

 

[Reedys]

Update: Going to replace all my cables & add a transmission to chassis ground. If it still doesn’t fix it, I will re-pull the ecu and drop it off to a shop for testing of the caps. Wish me luck

 

[LDRF]

Wish me luck

Good luck!!!