Lack of low down power

Hello

I am new to this forum but have read quite a bit about similar issues..

We have a 2005 TD4 which has no power low down in the revs.... it was also having issues with less than a 1/4 of a tank of diesel...

So far I have replaced the fuel pump and filter, cleaned the EGR and just replaced the MAF...

The 1/4 tank issue is now gone, but the new MAF has made things much worse.. barely revs past 2,500 rpm and has even less power... So going to put the old one back on today...

I have tried to check the turbo boost solenoid and when I look at the actuator when someone starts the car, it does move.... unlike my fathers which seems to be stuck...

Can anyone suggest any additional fault finding I might try to diagnose the issue?

Thanks

No power low down? but power higher up?

Doesn't sound like fuel pressure. Could be a turbo issue.

Any smoke? any amigos on?

Fuel pressure was causing issues when the tank was below 1/4.. but that is now fixed...

I did wonder about the turbo, but I understand these suffer quite a lot with the actuator.... so wondered if there was a way to test this first...

I also understand they suffer with PCV issues... so I am just ordering the replacement BMW part that does away with the mesh filter, and will fit that once it arrives...

Have you replaced the turbo vent filter. Hangs down the back of the engine. About £3.00.
Mike

No.... I'll take a look at that today as well... Thanks

Did you use the correct MAF. I think its only the Bosch that works. If you want to use the cheaper pierburg, you need to use a synergy chip.
Also there's a MAP sensor on the left hand side of the manifold, which affects performance, usually at higher speeds though.
Mike

Oops
Don't press send twice!!
Mike

Heh..

It is a Bosch MAF, but after putting the old one back in things are a little better...

I'll replace the PCV valve for the modified BMW item and change the turbo vent filter as well.. then I will see where I am at...

Staggan said:

Heh..

It is a Bosch MAF, but after putting the old one back in things are a little better...

I'll replace the PCV valve for the modified BMW item and change the turbo vent filter as well.. then I will see where I am at...

Click to expand...

hi mate

have u checked ur vacuum hoses

ref the maf sensor there are some cheap cloned ones from eBay

have u tried unplugging the maf, driving it up the road to see if there's any difference

Inlet manifold may need cleaning

as the guys have said check out ur map sensor to see if the hole in the middle of the sensor needs cleaning out, use an electrical cleaner

also have u had a look at this site

Maf sensor problems.

hope it helps a bit

ps where abouts in the UK are u plse,

I cleaned my map sensor and it is much better for low down toque .

As Gstuart says its worth checking the vacuum hoses,especially the one across the top of the engine inside the sleeve.