Strange feeling on high speed cruise

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

G'day all,
Had a slight issue today,not sure at all what it might be.
On cruise control at 110kmh going up slight hills the car would sometimes feel like it was dropping back a gear but there would be no change in RPM or anything. On the downhill side of the same hill it would feel like it did the same thing. It's a minor 'bump' but noticeable.
Initially I thought it was the tailshaft clunk but I've had that before (solved with a good greasing) and this felt different to that. In my reading about the tailshaft clunk I don't recall people talking about it occurring at high speed.
I feel I've ruled out a fuel pump issue as when I flatten the accelerator to overtake it doesn't hesitate or anything.
I've read a little about suction control valve issues but the symptoms seem different to what people describe.
Only changes I've made to the car in the recent times to this occurring is I replaced my FM100 fuel filter and changed it to the post filter (as opposed to pre-filter) When I did this one of the barb fittings got super loose (which was like that for the drive today).
My possible chain of thought is that due to the loose fuel fitting a little bit of air is getting in the fuel line every now and then?
Can anyone else shed some light on this?

Thanks

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

Does it happen at the bottom of hills when you coasting down (with cruise control on) - feels like a slight hesitation? I had this issue and it was a software fix for the cruise control.

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

I had a very similar problem. Can't find the exact thread but it was fixed by an ECU update. What year and model etc. is your Prado?

Also have a read of this http://www.pradopoint.com/showthread...ght=Hesitation

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

I had a very similar problem. Can't find the exact thread but it was fixed by an ECU update. What year and model etc. is your Prado?

Also have a read of this http://www.pradopoint.com/showthread...ght=Hesitation

That sounds exactly the issue I have. Mines a 2010 auto.

It happens at the bottom of a slight hill when the car needs to put the throttle back on. It almost feels like the engine has turned off briefly then come back on.

The car almost has 160,000k on the clock and I've never noticed it before this weekend and I've had the car for 70,000 km and it's never done it before. Is that normal for it to develop over time?

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

I only noticed it after 60000km, very strange but resolved with the ECU update.

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

I rang Peter Kittle today and they have no idea what I'm talking about with this ECU update

[carl1965 Lurker Find all posts View Profile Close carl1965]

Tell toyota TFN-52-12 Prado hesitation.
It fixed mine i didnt notice any problems till driving in Tasmania, not many hills in Port Hedland.

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

Yeah that's the code I told them. I'll try again tomorrow. Once again Peter Kittle Alice Springs quality

[vk2ss55 Senior Member Find all posts View Profile Close vk2ss55]

Mine did the same thing , also hesitated accelerating out of roundabouts . The service dept tried tried to sidestep the issue so I gave them the Tojo fixit that I'd printed out from Pradopoint ! Reflash was done and problem fixed however I reckon the fuel consumption increased after that .
Cheers Ross
He

[Rick21 Junior Member Find all posts View Profile Close Rick21]

i dont use my c/control as it surges on hill accents, wastes to much fuel, l go old school and regulate my speed by accelerator.

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

So I went in again and they found it. They said it would cost me about $65 to do it (0.5hr labour). Can anyone suggest any way I can argue it as a warranty issue even though my car is 160,000km and way out of warranty?

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

So I went in again and they found it. They said it would cost me about $65 to do it (0.5hr labour). Can anyone suggest any way I can argue it as a warranty issue even though my car is 160,000km and way out of warranty?

They sound like dicks, it is an update issued to fix a known fault with the car.

If they want to play hard ball type a letter that says that you are concerned about the potential impact of this issue on the safety of you, your family and other road users. Deliver it to them, Toyota and the ACCC asking them to respond in writing that they are refusing to implement this fix.

There are laws that cover this, some of the other people on this forum may be able to point you in the right direction. Honda did a recall on my wife's car that was 10 years old and we were the 3rd owners.

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

Got the update done today after chasing them about it over multiple phone calls and visits. They grumbled the whole time and their customer service was very sub par. They charged me 68.50 for it in the end and gave me a big lecture about it when i picked it up about how this update is irreversible and it's not their fault if it doesn't work blah blah blah. Questioning if they even did it then?
As for the $ i paid. If it works then i'll get over it soon enough.

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

Sounds like Kittle to me!! Printed out a list of requests for the 90k service.. Nothing crazy, just asking to use my parts in the boot, change fuel filters, keep my old filters.

None were done with the exception of changing the fuel filter. On picking up the car after a 35min wait, the dash mat was still draped over the front passenger seat! Also charged $420 for the privilege... With my parts provided! I'll give Central Diesel a try next.

Good to hear the flash might help your trans. Surely there is a warranty/case for free software updates. It's just like an update for your PC/phone etc