Acceleration issue - Help needed

[dean96 Lurker Find all posts View Profile Close dean96]

I didn’t want to put this under general or transmission ect as I’m not sure what my issue could be I’m just after some general advice.

I have a 2003 4Lt 120 Series Prado ( Automatic) 80'000 kms
It has a full Service History but over the last few months we have had an acceleration issue only when taking off.
Were talking like stuck in first gear really slow maybe 15kmh then it kind of boots in and runs fine with no issues but if we come to a stop it does the same.
Now our Mechanic said its the catalytic convertor but the local muffler shop said if this was the case the car would be doing it all the time and more than likely stalling.
The gear shop bloke said if it was first gear the second would go or be rough due to the stress of the first gear being stuffed.
Has anyone had this issue or any ideas?
I’m keen to have it fixed but id rather have some idea what could be the issue otherwise its clearly going to cost a ton in diagnostics.
On a side note one shop said they have 2 catalytic convertors and another said 4 and the local Toyota dealership were of no use and didn’t get back to me at $400 per Cat to be installed I’m hoping its 2 lol

Thanks for any help

( mods sorry if this is in the wrong forum)

[Matty80 Avid PP Poster! Find all posts View Profile Close Matty80]

Just as a clarification, is it "stuck in first" and the engine seems to be ok?
Or is the engine having issues with power and subsequently, it doesn't change out of first?

I'm thinking that if its only at the lower rev range then you may want to have a go at cleaning the air flow sensor, i think there is a thread on this on PP somewhere if you need some info on the topic.

Short of that, I'm not sure.

[timmay5.7 Advanced Member Find all posts View Profile Close timmay5.7]

try driving with the 2nd start button pressed for a while - is it different?
p.s. put your location in your profile somewhere

[dean96 Lurker Find all posts View Profile Close dean96]

Second start makes no difference and I really dont think its the gearbox as the engine sounds like its really pushing for acceleration and almost breaks through and then is fine,
I thought it could have been dirty fuel filters so they were replaced at the 80 thousand major.
( also updated location lol sorry bout that)
will search for the cleaning of the air flow sensor

[dean96 Lurker Find all posts View Profile Close dean96]

So the air flow sensor was filty took about 30 mins ( with drying time ) the spray was $20 at supercheep auto so at least that has now hopefully stoped a future issue
With second start button enabled and a long drive there was no acceleration issue at all, it was like driving the car new again, so sadly that makes me think my first gear is stuffed.
Im really hoping this wont cost a fortune lol
on a side note my electric windows died lol but thanks to PP I found the fix quite fast ( thanks )

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

Could be the transmission speed sensor - I had a similar problem with a 90 series, changed the sensor - all ok

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

how long do you warm the engine for before you drive awway . mines an 03 and it barely warms up before it get's to its destination . mine does not like to hit 3rd gear before its done at least 1/2 k to a km . it will hold 2nd till it warms up . i have 173000 on the clock and it does't get much time to warm up . its serviced with only the best oils on the market . personally i think they just need a bit of time to warm up especially in winter .

[MDS69 Advanced Member Find all posts View Profile Close MDS69]

When I read the title of this thread I thought you had an issue with too much acceleration, something the diesel boys wouldn't know anything about.....


Apart from that I have nothing else to add

[dean96 Lurker Find all posts View Profile Close dean96]

Turned out to be the spark plugs its been about a month since I changed them and we havent had one issue,
I think it was number 5 was completely caved in no spark at all as the metal part was caved into the white electrode part, and number 2, 3 we so loose I undid them with my fingers and burnt oil was all over them,
But yeah knock on wood its sorted lol

Ohh Id like to note this was Toyota Southside brisbane that had the full service history and "Changed" the plugs before we brought the car lol

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

@MDS69, spark plugs. Something the diesel boys also don't know anything about.

Apart from that I have nothing else to add ;-)