Well done fik c it is always good to get feed back rather than like some guys who just keep quiet once they have got the information and fixed the problem.......... I have come across blocked manifolds on the Toyota 4Y engine a lot, seems to be when the engine starts to get a little bit worn and starts to breath through the PCV valve, the gunge then builds up on the hot spot between the exhaust and inlet manifold...........I have seen them so you can hardly get a screwdriver through the hole!

Thanks for all the help. Manifold was the problem. Not dumb Prentice, plastic wrap is causing us a lot of problems, like broken fanblades damaging radiators.

Do not take this the wrong way but i have seen this happing allot. Check the air intake on the back right or left overhead guard. Make sure that the driver has not put plastic wrap on top to stop the rain and blocked off the air intake. It sounds dumb but i have seen it stall out an engine

Looks as if you have tried just about everything, has the 6 series got a 4Y engine? if so I agree with snapman, it could be a blocked manifold, but you would have seen this if you had the governor off!

Thanks.I replaced the fuel hose and checked + adjusted the governor.Will check the manifold.

I've seen the fuel hose from the regulator to the carburetor collape or crack and cause a no rev up problem on Toyotas.

did you check the or replace the governor too?

Is the inlet manifold bloked up as this will give you that fault.