406 hdi slow

[topbuzz]

hi all ive found this forum whilst browsing for issues on my 406 since ive owned the car it seems very sluggish on take off .from what ive read a lot seems to point to the maf sensor so today i unplugged it and it seems to have given me better power does this mean the maf sensor is goosed or what im gonna plug it back in and see the difference ..

[Uberderv]

Could be. By unplugging it you make the ECU use a set of default values. As a low cost test remove the maf and look inside, you will see a section with a very thin flat wire at the end. Give that a blast with brake and clutch cleaner and see if it makes a difference when re fitted.

[Doggy]

Hi and welcome aboard.

If you add your location, someone nearby may have diagnostic kit to prove if it's the MAF, or perhaps let you substitute theirs to prove a point.

[topbuzz]

i live in fleetwood near blackpool if anyone has diag or more knowledge then feel free to pop round as my leg in plaster so don't really want to drive far at the mo

[Welly]

Yours is a HDi 90 so as far as I recall the MAF is only there to check the EGR function.

The 90 is lazy but you could check the Turbo hosing's for signs of leakage etc.

[topbuzz]

ok i have a haynes manual that came with the car so will study that and take a look..
ive had it on the motorway doin nearly a ton so the powers sort of there its just at junctions it doesn't seem to have much get up and go ..

[GingerMagic]

Have you checked the slack in the throttle cable? Its basic stuff I know, but easily overlooked.

There should be a clip on the cable, by the throttle body, this needs to be pulled off ( ooer ) take up the slack in the cable and push the clip back on.

Next I would be using the super diesel for a tank or two to see if it improves the cars performance.

[rwb]

The MAF reasoning sounds good to me.
Another possibility is a sticky EGR

[topbuzz]

ok guys i will take alook over the areas hopefully tmoz and report my findings

[gumby6371]

Not very familiar with the 90 do they have bulkhead EV's for the EGR and turbo? vac leak stopping the turbo actuator from opening? They're default postion is closed with no vac IIRC??
At least the lack of intercooler limits the possibilities, every cloud and all that.....

[Doggy]

90's don't have a turbo electrovalve - just a mechanical wastegate

[stuartkeith]

the 90 is turbo? my 90 struggles to top 80mph. is this normal? Ive not worried about it, as im getting 6-700miles a tank from it

[Doggy]

HDi 90's have a turbo, but lack the intercooler and electronic boost control the 110 has.
Power unsurprisingly, is 90 BHP. Should be good for about 105/107 real* mph.

[fattail95]

My 110 pre-remap could see 120 given a long private* piece of road. So I'm sure a 90 could at least top 100, even though power is quite low they have decent enough torque.

[stuartkeith]

So normal then. Downhill can do about a ton.


Sent from my iPad using Tapatalk