406oc.co.uk

Cool.

It's common for the MAP sensor to get a little dirty - some oil vapour blows through the intercooler when driving, it can after a while block the tiny pipe or the sensor on the top.
This is fairly normal, and the oil vapour burns up in the engine anyway.

A leaking intercooler is also common, usually the bottom corner - shouldn't be an issue unless you can see air bubbles coming out.

the intercooler has been getting worse for about 2 yrs ?
there is air bubbling out at the bottom !!
they are about £70 + on e-bay, been trying to find one a bit cheaper!

I've sealed the crack in the intercooler and fitted an other air pressure sensor, disconnected the maf sensor for a while , but the same!
noticed when it happens , if I pump the throttle the power slowly comes back

Hmm.
Okay, that eliminates a few things...

I'm curious about the throttle sensor, maybe the loss of power is a sticking throttle position sensor, so if it sticks in the 1/4 power position then that's all you'll get..

RWB had a reoccurring fault with his, which he resolved by cleaning it out - there should be a guide on how to do it here somewhere, it's one of the easier jobs to do.

viewtopic.php?f=1&t=19303&p=191872&hili ... or#p191872

just a thought :
seen a thread that suggested the high pressure fuel regulator could be the problem ?

It's possible.

Sometimes all they need is new O rings, but I don't believe they are too expensive to buy - depends on your budget I guess.

Easy enough to replace, but as always don't be heavy handed as these are a bit more delicate.

Have you tried cleaning your throttle sensor?

not cleaned throttle sensor as one of the bolt heads is damaged, might see if can get one from e-bay
cleaned quite a few connectors today , took it for a run and just the same
I'll run over the symptoms again when I 'm accelerating and the turbo cuts out or goes into limp mode ? If I floor the throttle the engine slowly comes back on song ? . Its sometimes runs fine !
Its like as though its waiting to get enough fuel ??

Result:
The old 406 keeps on trucking !
Just got the car through another MOT !!
needed front discs/pads, rear pads, and the callipers feeing off ! with MOT = £220
still got the air pollution problem , as long as you don't hit the gas to hard it's ok
not bad for a 20yr old car
cannot believe the sills were not condemed

i'm having trouble with something similar, i get an engine warning light though. i'm pretty sure air is being dragged into the fuel lines on mine. i have a little inline filter and can see lots of bubbles. I wonder if the is a problem in the fule tank (filter there clogged or tankpump gone?) but there is a plate of shaped steel riveted over the point of access to the fuel tank and i am not sure how to get it off with causing damage.

update:
fitted new throttle cable unit, no change to problem
have noticed the mpg is now showing 54 mpg instead of usual 50, poss fuel pump/pressure/pressure control valve ?

had a go at fitting a sill ! what chore ! never tackled anything like this before, got one side done.
will not be doing the other side anytime soon !

update:
gave the throttle body a good clean, it has improved things but, it is definitely getting starved of diesel
seems to be either high pressure pump/fuel pressure regulator ??
going to wait to see if the old girl will get through the MOT without too much work !!!! , role the dice once more

update:
passed Mot !, only advisory was needing 4 tyres shortly , which I knew about. RESULT

Hello i have the same problem with my 607 2.2 hdi engine .. do you have any vacuuc circuit diagram , because the mecanics in my place dont know how to fix the error .. thanks