Engine trouble

hi, after some help/advice please
My td4 manual has developed a strange fault, under normal driving all is fine, uses no oil and averaging 40mpg. However it will not rev above 3500rpm when it gets to this it just splutters about until I back the throttle off, it does this driving and stationary.
Any ideas? Thanks.

If could be your crankcase breather that's clogged up, or your turbo solenoid is faulty, or it could be your low pressure fuel pump on the way out. Or quite possibly something else.


Mike

So I have given this a service oil + filter
Fuel filter
BMW crankcase breather mod
Turbo vent filter
Cleaned inlet manifold and done egr bypass mod
Problem still the same, I have unplugged maf ( I think under left hand bottom of inlet manifold?) doesn't make any difference. Also pulled pipe off of turbo boost solanoid (this makes it pull away really slowly but still won't rev above 3500)

When it gets to 3500 rpm when foot to the floor it just revs and slows constantly.
What should I try or look at next please?

Low pressure fuel pump and/or o rings oon hp fuel pump

Are these easy diy jobs to do?

Landytd4 said:

I have unplugged maf ( I think under left hand bottom of inlet manifold?) doesn't make any difference. Also pulled pipe off of turbo boost solanoid (this makes it pull away really slowly but still won't rev above 3500)

When it gets to 3500 rpm when foot to the floor it just revs and slows constantly.
What should I try or look at next please?

Click to expand...

That's the MAP sensor. It won't make much difference unplugging that, if another fault exists, as the ECU will set a default value to it.
The MAF sensor is on the end of the air filter box. The ECU will limit fuel if the MAF returning a low air flow valve to the ECU. Unplugging the MAF will set a default in the ECU which doesn't limit fueling and should improve power, if the MAF is at fault.