Hi,
I've been advised by a tuning firm that have chipped my other car that you can get upto 30hp more power and more torque out of an older 4.2 TD landcruiser just by disconnecting the vacuum pipe from the top of the valve. He said just stick a suitable size bolt in the pipe with a zip tie round it to seal the vacuum pipe and leave the tube on the valve open. He said once they've done something like 50,000 miles they don't work anyway because they clog up, usually sticking open and leaving them open puts hot exhaust gases into the inlet manifold which isn't good for performance.
Is this advice correct? and would it do any forseeable harm to the engine if i tried it anyway.
Any advice on this subject would be appreciated
Thanks
Richard