C5 2.2 HDI Low Power and Sluggish

corsehf · Post by **corsehf** » 30 Mar 2010, 16:02

Hello Kev,
Which AFM did you pick up from Ebay??
I have noticed several comments that some don't fit, some don't work and some do!
I have also read comments that the 'cheaper' ones are not worth buying over genuine due to poor quality etc.
How is your car running with the new AFM??

KevMayer · Post by **KevMayer** » 30 Mar 2010, 18:46

The air flow meter i fitted is this one.

It was cheaper than I remembered at £34.95.

http://cgi.ebay.co.uk/Air-flow-mass-met ... 414860b9ab

I've been driving my C5 over the last few days and it's going very well. I'm really puzzled as to what has been going on. I still haven't worked out what the fault was. All I can say is that since fitting this air flow meter it's running as well as it's ever been.

h2ocooler · Post by **h2ocooler** » 15 Jul 2010, 00:24

Hi Kev
How is you C5 running now? I read this thread and think my MAF might be knackered, I had a look at it today and it too is green, cleaned some of it off with carb cleaner and it seemed better, it has always seemed sluggish from standing start, not really pulling until the revs reach 2000 so for a few seconds other cars get the jump (then it leave's them standing)

I had the anti pollution fault appear about 6 months ago coming back through France when it was CHUCKING it down, it cleared the next day but a few days ago it came back, was doing a short trip (less than a mile) plugged the Lexia in but could not see what the fault was (only temp sensor) Done a far few miles since and not come back.

A few times when driving the car does seem to loose a lot of power, no warnings at all but it will struggle to do 70 on the motorway uphill, changing down to 3rd gear and revving to 4000+rpm so I know its not in Limp mode. I have checked the vaccuum side and getting no signs os a vac leak.
Rob

cachaciero · Post by **cachaciero** » 15 Jul 2010, 09:06

h2ocooler wrote:Hi Kev
----snip----

A few times when driving the car does seem to loose a lot of power, no warnings at all but it will struggle to do 70 on the motorway uphill, changing down to 3rd gear and revving to 4000+rpm so I know its not in Limp mode. I have checked the vaccuum side and getting no signs os a vac leak.
Rob

Could be a lack of boost, when you checked the vacuum system did yyou check that the actuator on the turbo actually worked if this was seized / stuck then you would still have some boost but not a lot particularly low down.

cachaciero

h2ocooler · Post by **h2ocooler** » 15 Jul 2010, 11:07

Hi
No I haven't checked the actuator but have looked on the Lexia and the boost pressures seem to correspond with the called for pressure when reading real time data.

I put a vaccuum guage on the system and getting 700mm vac at idle.

Im off to France again tonight and will try and have a look when I get over there, also will see how she behave's.
Rob

cachaciero · Post by **cachaciero** » 15 Jul 2010, 15:07

Rob

Another possibility related to fuelling comes to mind, from reading various fori it would seem that failure of the lift pump on the LP side is not uncommon and it would appear that it can intermitently starve the HP pump long before it finally dies, just a thought.

cachaciero

KevMayer · Post by **KevMayer** » 15 Jul 2010, 18:35

My C5 is running ok at the moment but thats after I put some injector cleaner in the tank with 20 ltrs of diesel.

My theory is that dirty injectors have been causing problems with fuel rail pressure. I picked this little gem of wisdom from something Wheeler said a while back.

I used Comma Diesel Magic and my C5 is now running better than ever and its on the 3rd tank full since the flush through. I got it from Halfords.

I'd be interested to know if it makes any difference to yours.

KevMayer · Post by **KevMayer** » 16 Jul 2010, 20:31

Any news on this one?

h2ocooler · Post by **h2ocooler** » 16 Jul 2010, 20:40

In France at the moment, but will try the injector cleaner when I get back.
I did clean the MAF with carb cleaner before I left and it didn't loose power on the way here at all, still sluggish pulling away but not as bad, will get a new MAF as well.
Rob