a mate got a new turbo fitted reciently and i was there when it was being fitted it was done right.heres the problem.when we left the garage for a blast the engine developed a miss or what appeares to be a rev limit at 4000 rpm reguardles of boost setting (16 psi to 20psi) it will even do it with the car stopped and you bring the revs up to 4000 approx.the she limits sounds like bep bep bep bep.........
if you push flat out it still wont go above this rpm even when stopped.
and its not happening all the time but it appears to be getting worse
we have changed, dizzy,crank sensor,map sensor (3 bar),plugs,leads,coil,
but its not making sence as it drove in perfect.its like hitting the sound barrier at 4000 rpm but from idle up to it and beyond it all is ok.i know the obvious thing to suspect is the turbo but it happens also when unloaded and only at one rev setting. i need the guru.s on this one

 

Check all your sensors are plugged in - mine went like that when i forgot to plug the coolant temp sensor back in after I changed a blown coolant hose!!!!!

 

Its in limp home mode. Total sensor failure mate.

 

cheers lads any idea which one as there is a secs monitor hooked into the ecu and all the readings are normal for map,temp,tps,coolant,voltage.rpm.

 

Ahh, just read it properly!!

A turbo was fitted eh?

Plug the lambda sensor back in

 

Why didnt you take it back mate?

 

well the man was scratching his head aswell ,i,m almost sure the lambda is back in,i didnt think the p8 was that sensitive if the lambda was nuked or missing.i melted the wires on my 4x4 saph lambda sensor and had to disconnect it and it never did that although i know its an L8
thanks for your help

 

P8 will introduce a safety 4K limiter upon ANY sensor failure mate.

 

thats the kind of info that is worth its weight in gold .thank god for passion ford and all who post in her

 

Let us know if you fix her, so anyone in future can refer to it.

 

will do.looks like a few nights with the meter and the probe.

 

problem sorted turned out to be a nuked lambda sensor
cheers stu

 

Stu

 

Glad its sorted mate