Flat Spot on C5 HDi 2.2

corsehf · Post by **corsehf** » 06 Jul 2010, 21:12

I have a Flat Spot on my 2001 2.2 HDi??
All filters are new, DPF is fine, have tried a different AFM but to no avail.
It can be quite dangerous if not ready for it.
It can cause you to stall the car at lights etc but also can be very dangerous at T junctions when pulling out only for the car to just die half way across - the only sure fire way to do it safely is with plenty of throttle and with the passengers suffering from the unexpected g-force!!

Any ideas anyone??

Post by **myglaren** » 07 Jul 2010, 06:28

Dirty/worn throttle pot perhaps.

corsehf · Post by **corsehf** » 07 Jul 2010, 11:18

I have read on here somewhere about the cable may need adjusting but i did check that and it appeared ok.
I did remove the pot to see if the contacts were worn but it was a sealed unit. Other than getting a spare, is there another way of checking?

Post by **myglaren** » 07 Jul 2010, 17:25

You could try putting an Ohm meter across the terminals and see if the resistance changes smoothly or if there is a dead spot somewhere as the pot is operated.

KevMayer · Post by **KevMayer** » 07 Jul 2010, 18:02

I've had this on my C5 2.2 Hdi.

Looking around the internet I concluded that it may be a problem with dirty injectors, so, I first tried putting loads of Redex in the tank and this seemed to clear it.

I got the same symptons recently so went to Halfords and got some 'Comma Diesel Magic'. This treatment fluid appears to have good reviews so I poored it all in with 20 ltrs of diesel.

The jury is still out, but, my C5 seems to run much better.

The Diesel Magic cost £5.99 so is worth a go.

KevMayer · Post by **KevMayer** » 16 Jul 2010, 20:30

Any news on this one?