Sluggish acceleration, gear changes with abs and trc lights

[2000Prado]

Hey guys, Prado's been back to the auto elec who said there was oil and some brake dust on the sensor. He cleaned it up and said there's possibly a leak somewhere, but said he's not really sure where (wondered whether it's the diff) and that's not his field. I've driven it about 60kms since then and no issues as of yet; if it goes again will be heading to a mechanic to work out what's causing this problem.

[Leethal]

Perhaps check the sensor clearance is correct, if it is mounted at or more than the maximum clearance it will not function correctly and could post an intermittent code.

Lee

[RedAdventureWagon]

Wiring/connector? The fact it was fixed for a few days would to me indicate the module works. Maybe worth disconnecting that wheels sensor and cleaning up the connector contacts.

[2000Prado]

Unfortunately, three days and less than 30km of town driving later, the issue with the ABS has returned. Still drives beautifully from the MAF point of view, but the ABS and TRC lights are back on the dash (no grinding as of yet), which is somewhat irritating. If it turns out to be the same issue again, I'm left scratching my head wondering what underlying problem could make a new wheel speed sensor fail in 3 days :/

[RedAdventureWagon]

Great news

2000Prado

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2000Prado hope it stays that way! Thanks for the update, seems that MAF and TPS are chiefly responsible for the sluggishness on the 5VZ, nice to know what parts to focus on.

[2000Prado]

Well 10 weeks later I've finally got the car sorted out. Replacing the front left wheel speed sensor has fixed the ABS lights and grinding issues, and today I got a new MAF sensor fitted and the car drives like new! Obviously a clean wasn't enough, but with the new MAF the sluggishness and throttle issues have disappeared and it drives a dream.
Next step is to do the shocks and tyres, and get it out on the tracks. Thanks all for the help!

[2000Prado]

Thanks for all the advice, Kernal and others! Car's finally made it to a mechanic here, who couldn't figure it out, but referred me to an auto electrician. He's just told me the FL wheel speed sensor is malfunctioning, which would explain the grinding and abs lights. He hasn't found the source of the throttle issues, but he'll have a better look once the ABS is working again. I'll be encouraging him to check/replace the TPS if he doesn't find the cause elsewhere. So far thankfully sounds like the transmission is OK.
Thanks again guys; I'll get back to y'all when I get another update.

[watsea]

I google searched "what is a TPS" and one of the hits was a YouTube about symptoms and remedy. The symptoms were very much like that have been experienced by 2000Prado and Kernal1455. Good luck.

[RedAdventureWagon]

Great write up thank you! If the sluggishness comes back in mine I'll definitely check the TPS.

[Kernal1455]

OH BTW, you dont need a toyota screw for your MAF just use anything that bites and is not too long. its only a fixing. (i had the same issue on my falcon)
Kernall1455

[Kernal1455]

2000Prado,

Just reading through your post and i think this could be the same issue i had. Firstly i must mention i never had the tranny noise but it was suggested my tranny was on its way (what a load of %$&#) i did also have the TRC lights come on but im not sure thats related either (having said that it has not happened since i fixed the power issue)
I was experiencing a massive lack of power when planting the foot, car would not kick down unless done manually. If i was at cruising speed and went to overtake no matter how far i pushed the pedal it would just lag in revs and take ages to pick up speed, hills required manual gear down to 2nd. etc etc.

It was like this for over 18 months, all the mechs i took it to gave me all different answers (none got it right, including toyota) First mech told me it could be the gear box and he adjusted the kick down- that just made the changes more aggressive, wasn't going to go down the gearbox road on a whim. Next was Toyota they said it's feels normal and said it probably feels sluggy because i had put micky thompsons on, yep they blamed the tyres, regardless of me telling them the tyres came a year before the issue was present. Other mechs said it was fine or maybe gearbox or kickdown and it just kept going in circles. The other symptom i noticed was the extremely rich smell from the exhaust and the blackness in the pipe.

I though i would tackle this one myself, did some research as to what the prados have and don't have...My list of things to try was quiet small

1- MAF sensor - cleaned it and refit, test drive noticed a little improvement but not enough to be the issue. I then though maybe a previous mech had stuffed the maf when cleaning, so i replaced it with a new one...a little better but again not the issue.

2-Exhuast - my exhaust was getting to the end of its life, i had read that the manifolds on theses are a bit restrictive... so i researched options to improve economy and performance.... started a post on here about pacemaker extractors and exhaust system. Decided to replace the exhaust and fit pacemakers after talking with the designer of them in SA who at the time was testing the prototype on his parents Prado. Heaps better obviously, but not the issue.

3 - My current mech used to work for toyota before going solo, he suggested a gearbox service... This was promising and made a fair bit of difference, actually for a moment i though it was the answer.....felt better but not the issue again. soon the car felt the sluggy again. (if you have never done this it is worth it)

4 - TPS - I had a new replacement onein my garage for about a year before i changed it, becuase one of the screws on mine was stripped and due its location being very close to the fire wall i couldn't remove it worth out uninstalling the whole throttle body and stubby screwdriver could not get the purchase required. So on the next service i got my Mechanic to replace the two screws with hex head fixings, i had intentions of replacing the TPS myself. Anyway i got lazy and ended up getting the mechanic to do it for me on the next service again, he swapped out the TPS set the idle and reflashed the ECM or whatever he needed to do.
THIS FIXED ALL MY ISSUES INSTANLY!!!!!!!!!!!!!!!!!!! The car felt right again!

After all that it was a simple failing TPS- which i had tested several times with a meter and was suspicious as the reading did jump and wasn't as smooth a curve as i would expect. So i have put it down to wear and tear on the potentiometer .... really that's all thats in there.
Now the car drives like it should (actually way better than it was because of the extractor upgrade.) When i push the pedal it kicks down as expected.

After all that the fix was $118 for a genuine toyota TPS that no mech ever suggested to check!

There should be 3 wires to your TPS a +, -, and signal. with meter check for voltage going to the TPS, then check your ground. to test the operation of the TPS back probe the signal with the positive probe and the neg probe on the ground wire or chassis, you should see about half a volt when the throttle is closed, when you start to open the throttle slowly the reading should increase smoothly to about 5 volts a full throttle........if your reading is not smooth and sort of jumping around, intermittent or not going up at all as you depress the throttle the TPS is stuffed.....
Most likely worn carbon tracks (they work much like a potentiometer i believe). Change over can be done yourself you will need feeler gauges to set the idle position and I am not sure what ny mech did as far a the reflash after installing TPS. I would think he just reset it, otherwise i believe the ecm will take a while to readjust as its been getting incorrect readings from the tps and calibrated itself accordingly. probably the rich smell it used to have.


Hope this helps with your issue,,, apologies if it's not the solution in this case, and also for the length of the reply.
Be interested to hear your outcome.

Kernal1455.

[2000Prado]

You guys make good points. I don't think it's just the trans because the slowness isn't just related to gear changes. The delay in acceleration after pressing the pedal is beyond any other car I've driven, and happens even when I wouldn't expect a gear change. Overtaking at highway speeds in my Dad's Tarago you'll get acceleration as soon as you press the pedal and not necessarily a kickdown within sensible limits. In the Prado though, you've basically gotta hit the floor 4 or 5 seconds before you want to start speeding up, then wait... kickdown, lurch and power. You can be driving highway sometimes and gradually start depressing the pedal until you've pushed it quite a way and there'll be no difference (power, revs) at all. That all makes me hope it's something to do with the throttle sensor or something. If I find time might try to figure out how to have a look at that myself too.
I gave the MAF a good clean. Still waiting for the replacement screw to turn up out here and then I'll give it a test drive, and mess around with the OD and lower gears; will report back.
I'll do my best to find a good mechanic out here (I'm out back) - have already got an eye on a bloke who's been recommended to me by multiple independent people here. Hopefully he knows his trans. Will visit him in a week or two.
Cheers all.

[Leethal]

Did you give the hot wire inside the MAF a good spray and rinse? It is possible to read the trouble codes by bridging two pins in the OBD-M connector, I can't remember which two but should not be too hard to find out. The transmission cable is a simple adjustment to assist with kick down however from your description I think it is more a engine issue than a trans issue. I would be checking the intake system to ensure no leaks especially the IAC & associated piping.

To confirm it is or isn't the trans have you tried manually selecting a lower gear when accelerating?

Lee

[RedAdventureWagon]

Are you sure this isn't due to gear selection as opposed to engine performance? Is there any difference in ECT PWR mode, or if you turn OD off? Not a permanent solution of course.

There is a transmission cable from the throttle to control 'fluid pressure'. Some call this a kickdown cable but I have seen various opinions on if that's its true function. Perhaps this is out of adjustment?

Like I said the other thing I had done along with the MAF clean was a tranny service. Maybe it's worth getting this done. You need to find an old school transmission guy though who knows what cable controlled throttles are.

Certainly after getting mine done it has improved a lot. I can now get up hills. No sports car for sure especially with a trailer but it will at least accelerate slowly up them and doesn't drop like a sack of ssss.

[2000Prado]

Yeah, mine is certainly very gutless on hill climbs! Haven't really hit a proper climb in it yet (quite flat where I am now) but the one steepish hill I've attacked in it, it barely crawled up at 40kmh,a that was the one time it smelt a bit too. Subsequently did outback speeds and overtaking easy, just slow on the throttle. Will update in a couple of weeks once I find out what the problem is.