Member - Toonfish replied:

Not sure if you have the 2 f motor but diamond was telling me tonight about a motor rebuild he is currently doing on a 2f 80 series and mentioned they often damage cams!

hate to alarm you but sounded similair to your drama .

only passing on recent knowledge to me but cam shop sells plenty of cams for that motor on a daily basis too!

reason being only 4 bearing calmps for a 6 cylinder motor??????
many 4 cyl have 5!

just an observation , hope im wrong as it sounded costly
cheers

Simon C replied:

Check air clean inlet pipe from Air cleaner to Manifold. My perished underneath from the heat from the exhaust (Can not see it untill you remove pipe) It sucks in dirty air, and causes one of the sensors close to the Air cleaner not to read the correct air flow. Replaced mine, and engine ran a lot smoother When I purchased from Toyota....guy said "Another one !!!!" Worth checking all 4.5 Litre Petrols for this problem.

RenoRXGQ replied:

2nd the extra air being sucked in from somewhere. I have a GQ on dual fuel and had the clips on the air box broken off and it idled like a dog on gas. Air box fixed and no probs. I guess check all hoses for cracks etc.

Chris (W.A.) replied:

There is also a little rubber hose under the intake manifold on the passenger side of vehicle. My car wasn't running the best, I found that it had come off. It runs from the carbon cannister across to just under the manifold. Also check fuel filter and dizzy cap for splits or other wearing.
Regards