tb48 feeling a little flat :(

[armc89]

Hey guys im new hear and im in need of some help.
I recently purchased a 2002 tb48 gu its manual and done arour 220000kms its just had a reco head for gas but just running petrol now.
My issue is that its feeling flat from take off then at around 2000rpm she springs to life then around 3100-3200 its flat again then at 4000rpm it flys again ive been searching hi and low and cant find anyone with the same problem as me it starts and runs fine operating temp is normal no knocks or weird noises fuel usage is well....... tb48
Anyway if any of you have any ideas or can think of someone that is a tb48 wizard im more than happy to pay a shop or supply beers.
Thanks for reading guys and im looking forward to getting the patrol sorted and not making me angry when im trying to charge up hills on the hiway with the trailer on
armc89

[threedogs]

Not sure if your model has an Air Flow Meter,if it Does give it a clean
and refit it when its dry, SCA seel cleaner.
Check all your vacuum lines as well some may be perishing by now.

[armc89]

Hey threedogs my model has an airflow meter i gave it a clean and had a look for vacum leaks but the symptoms to me dont seem afm or vacum related it seams more like a management issue or something to do with the variable intake or maybe even vct. Hmm more investigation tonight i think

[threedogs]

You could be sucking air from somewhere
Has it been re-tuned to run on Petrol.??

[armc89]

Its still running the factory engine management mate shouldnt be any need for a retune i think ill just have to bite the bullet and find someone who knows tb48s

[98GU4.5]

My TB45 was the same, I ended up fitting extractors, high flow cat and new 2.5" exhaust (total new system less than $1000 brand new), as soon as I picked it up..... WOW!!!! is all I can say. It is now a totally different truck - no way comparable to how it was.

[Bulbous]

I'd say you need to look at the exhaust set up, seems you've got a problem where the torque should be maxing out on a TB48.
Easiest thing to check is whether the Catalytic Converter is choked. Especially as it was running gas which can mess with cats.
if the cat is blocked, then you could just bang out the centre, but as 98GU4.5 says extractors, hi-flow cat and exhaust can make the 4.8 fly

[garett]

x2 on the melted cat its a common prob on tb48's