Strange Issue with My V6 (ITS ALL FIXED!!!)

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

I have noticed some strange things with my 3.4 litre V6. The car when warm feels underpowered. The auto has a mind of it own and the things drinks fuel like i drink beer!! The best i have seen out of it was a trip from canberra to Sydney, no cruise, 90-100k's. she did around 13-13.5. My normal round town is 18-20!! :shock: so....its hurting at the moment.
The strange bit is when its cold, it flys! the auto behaves, the car feels strong, soon as she warms up, all back to normal, have tried the normal things, Cleaned and Airflow a million times, Plugs, filters etc. Im starting to wonder i might have to bite the bullet and replace the airflow as it seems that has fixed a few of these motors. The engine itself is fine i think, uses no oil over the 10k, comes out quite clean, no sludgeing i can see.
What are peoples thoughts??

[Dieselman Member Find all posts View Profile Close Dieselman]

Goanna,

I had a Commodore VN SS with the V8 that used to do the same thing, it ended up being the oxygen sensor. It was fine when cold but very doughy when warmed up?? Anyway changed the sensor and all good again. Hope you find your problem mate.

Ben

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

Re: Strange Issue with My V6

Well this week and mostly today i hit rock bottom with this Car, i finally got round to ordering a new Air flow meter as mine i believed was stuffed, $260 later, Plugged it in, started it up, engine light came straight on, Car ran like a dog..... brand new and Faulty, worse than mine. Returned, now just waiting for a replacement.

Then today.....
Went for a Trip into the Brindabellas with 4 other cars, car was terrible...i had no power, pretty much spent the day in low range so i could get around, got back to main road, could not keep the car in over drive..... started to think the worse, it was very dusty so i thought maybe the air filter was full, found a servo, blew it out, still no improvment. Tonight went over to friends house for dinner, again car pretty much now undrivable... half way home i remember one of the guys on PP that had similar problems acidently left his Air flow meter unplugged, he said the car ran better....well what could i lose, pulled over, ripped the plug off.....wow....i think i just about broke traction, i gave it a boot full how i have been driving all day to get the thing to move and it felt like all my problems were solved, the car flew!! the gear changed properly.... I now know 100% my Airflow meter is stuffed, i can't believe how important what this senser sends to the ECU is....mine must be sending all manner of wrong information. Not going to run the car long with it unplugged but it will do for putting around town. Im sure what ever it was doing plugged in was worse for the car!

Im excited to think that hopefully when i get the new meter the car will be how it should.....not how i have had it since i bought it.... Maybe i will start to like it again!

[Snaga Wishing I was lost Find all posts View Profile Close Snaga]

Re: Strange Issue with My V6

Maybe i will start to like it again!

I hope so

I hope this sorts it out for you. Mine is feeling a bit slow and sluggish of late too. I haven't actually had a clean run with a tank as I keep breaking things ops: ... hopefully the figures will come back down from 17l/100 :shock:
Might have a look at my MAF and see what state it's in.

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

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

Well after a very long drawn out sarga i can say finally the car is back to how it should be going! and im happy! the New Air Flow Sensor fixed all my problems. I still can't believe how such a small sensor can cause so many problems! The car feels like its got an extra 100 hp. Can't wait to play offroad again!

Anyone who has a funny running V6 prado! try cleaning your airflow, if it does not fix it, replace the bugger! Should have done this 12 months ago.

Cheers
Steve

[Snaga Wishing I was lost Find all posts View Profile Close Snaga]

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

Great news Steve... good to see it's all sorted.

Yet to calculate any fuel figures so hopefully my news is as good as yours

[Snaga Wishing I was lost Find all posts View Profile Close Snaga]

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

Anyone who has a funny running V6 prado! try cleaning your airflow, if it does not fix it, replace the bugger! Should have done this 12 months ago.

Cleaning it may not help if it's gone.

Another sensor to watch out for is the Throttle Position Sensor (about $160 off memory). Mine was found to be only reading around 80% throttle at full throttle, so it can also limit performance a bit.

Can all these bits be tested?? ... or is it just a case of replace it and see?

[MickL Addicted PP Member Find all posts View Profile Close MickL]

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

Both can be tested with a multimeter.

The throttle position sensor is a simple variable resistor/potentiometer and can be tested out of circuit.

The airflow meter needs to be tested in circuit and energised. This is done by back probing the the connector.

Details are available in Gregorys/Max Ellery/Toyota workshop manuals.

Mick

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

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

if you PM me your Email address ill send you over a copy of how you can check them.

The airflow should read about 1.1-1.5 vaults with the engine in park. Mine read 1.6, the reason i changed mine out.

[Snaga Wishing I was lost Find all posts View Profile Close Snaga]

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

if you PM me your Email address ill send you over a copy of how you can check them.

The airflow should read about 1.1-1.5 vaults with the engine in park. Mine read 1.6, the reason i changed mine out.

Thanks guys,

goanna... I've got the Gregory's manual. Is it in there?

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

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

Should be i guess, my info is out of a Haynes.

[Mikew09 Lurker Find all posts View Profile Close Mikew09]

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

Hi Goanna,
I purchased my 2000 Prado Grande V6 3.3 Auto about 6 weeks ago. The car has just clocked 89000 k and same as yourself, engine oil is clean, new filters, full serice history. Had the vehicle inspected before purchase and all is good, but once I started open road work and towing the horse float the engine appeared to drop two cylinders. I was very disappointed with the performance and could not beleive Toyota would put out a vehilce so under powered.
My specific issue is very poor performance between 2000 & 3000 rpm to the point it continuosly kicks back on open rd at the slightest incline. Only just got up the Toowoomba range with approx 1700 kg of horse and float, virtually at the point of having to stop and change into LR the last bit. Not what I expect from a vehicle rated at 2500kg. Only getting 18l / 100 unladen open rd, I expect it should be closer to 11 or 12 per 100 as my driving is all 80 to 100 K on open rd.

I contacted an old work colleage who has a 99 Prado and with 278 thou on the dial still pulls an 1800 kg trailer around the place and up the range without to much trouble. He also average 11.5l/100 open rd unladen. As most I have read about, I really like the vehicle but am unhappy with the prefromance and my 18l / 100 hyway unladen.

Took the vehicle to Toyota and they cleaned the sensor but commented it may be faulty - there was marginal improvement. I now have it booked into my regualr mech who has been brilliant with my GN Statesman to date. He tells me they have the gear and have dealt with such problems a number of times. Not surprised as we live in a country area and there is no end of 4bies. The other issue I had was the ignition key locking up which I had easily fix by a mobile mob - there is a post for them under the ignition problems subject.
Anyway, My mech tells me he runs the diagnostics out on the rd also as it may seem OK in the shop but will reflect poorly once on the open rd. It does give me some confort to read your post as it appears I have the same issue and have requested the sensor be replaced as part of the work in fixing this issue on Tuesday.

I will post the results of the fix later in the week for the benefit of others.

More to follow,

Mike

[Mikew09 Lurker Find all posts View Profile Close Mikew09]

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

Team,
Thought this may be of interest to others with performance issues.

My regular mech said the Prado seemed OK and there was no dianostics error except for a security breach (due to ignition barrell repair) - maybe just a little down on performance. I had read on the forum that the error code does not neccessarily show up with the air flow sensor that is a bit iffer. Armed with the knowledge (thanks Prado Point) I requested it be replaced anyhow. He also tested the Accelerator sensor and fuel supplies and filter - all good.
The cook picked the bus up and though sceptical said she was suprised it did not kick down over the hill past the school and said it seems to have a bit more go. I have just test driven and it now drives 100% better, in fact; one thing that really suprised me is the improvement in the function of the transmission - not sure what the relationship is but apart from not kicking down at the slightest incline (and I mean slightest) it changes so smooth now I hardly notice it. This pleases me but puzzles me also - hope someone has an answer as to the relationship. Actually a bit of a thrill to be able to accerator up a resonable incline (amazing change).

Anyhow, definately a different bus now, I expect the hyway and towing issues are now resolved. I don't expect it to perform like a super car nor pull like a mach truck but I do expect the vehicle to meet the user manual and documented expectations.

Have a run to Toowoomba this weekend and a run with the float (almost 2000 kg) to Marburg the following weekend, this will confirm the fixed and I will post accordingly.

Thanks to Prado Point posts from members, I think I have found the problem. Who knows how long it would have taken to diagnose otherwise.

Regards,

Mike

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

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

How good is it hey!!! Im still miffed how the airflow can affect so many components of a car but it does! By far the best money i have spent!! I was going to get rid of the car, i was over it. I felt like a slow fat slug and drank fuel like water! The best way if anyone is thinking that they might have an issue with there Airflow meter is unplug it, then go for a dirve, you won't be able to rev over 3000 but should take away your problems, i drove about 1000ks withit unplugged as i loved how it drove....until the sensor arrived!!

[Mikew09 Lurker Find all posts View Profile Close Mikew09]

Re: Strange Issue with My V6 (ITS ALL FIXED!!!)

Prado Point Team,
Just a follow up for any one with performance issues. As per my previous post, no dianostic errors when tested. Convinced the mech to replace the Air Flow Sensor and problem solved. Tested my Prado this weekend with a run to Toowoomba with about 40K running around town, all up 187 K on about 23 ltrs, I think that is about 12.2 ltrs/100 and plenty of power going up the range, no kick backs on the Warrego run from the range back to Lowood. Dragged the float with one neddy over to Marburg no worries. Pretty much says it all, AFS was definately the issue.

For any new owners with performance issues, defiantely search the forum before going to the mech as mine believed the vehicle was OK based on no error code no problem. Really liked the vehicle from the start and came very close to selling this vehicle but am now a converted owner.

Cheers,

Mike