hdi 90 - hesitation at low revs and coming off clutch pedal

[lazarus79]

the bumping off the clutch ... could this be an engine mount? put the h/brake on lift the bonnet put it in car and sharply jump it back and forth without stalling it and get someone to look if the engines lifting up stupidly somewhere? As for the stalling I did have one do this and it was the low pressure pump in the tank but its a far cry really, easy to check tho. Idle control valve?

[sirwiggum]

I was thinking engine mounts, but now I've a sneaking suspicion that its maybe that little clutch switch is sticking.

If I come off the clutch, the little clutch switch which was pressed in may be sticking, the ECU CPU thinks I'm still on the clutch, reigns in the fuel/air mix at 1500-1800rpm because it thinks I'm still revving, until the switch pops out fully again and it drives as normal.

That's the theory anyway. Might get some WD40 to test it.

[Welly]

That's a bugger wigg

Something seems iffy about this switch though cos you can create the problem when reconnecting it. You could try the WD40 or maybe swap it for a new switch etc?

I must say it's the first time I've heard of this jerkyness in general.

[sirwiggum]

The clutch switch looks exactly like this:



The "ribbed" bit goes in some hole (oo-er!) and the top of the clutch pedal levers back to automatically adjust the positioning of it.

When the clutch is depressed the top of the pedal machanism levers such that the black button there is switched, telling the ECU that the clutch is engaged.

*** Be aware if ordering from the Auto Gateway site that P&P is an unreasonable £13 ***

From what I can find out there are 2 switches.

- The brake pedal switch cuts out fuel
- The clutch pedal switch turns the fuel on again to prevent stalling

Obviously this explains why it was prone to very low revs / stalling when the clutch pedal switch was disconnected, as when braking it was cutting out the fuel but dipping the clutch was having no effect.

[sirwiggum]

Taking the key out for 10 minutes then disconnecting the injector plugs and the right hand red plug then reconnecting seems to have helped matters

Keeping an eye on it!

[Welly]

Definately some silly little fault somewhere, but where?

[sirwiggum]

Doing my nut in.

Still not driving right, difficult to drive smoothly on low throttle / letting go of the accelerator.

Diagnostic came back with nothing but the EGR I disconnected

[sirwiggum]

New clutch switch seems to have resolved the 1500rpm / coming off the clutch issues.

Just now need to solve the "jerking when I come of the accelerator" issue.

[sirwiggum]

The offending part

[Welly]

Hey, nice pic

Glad the new switch helped, hope the other one helps - weird though, no-one's ever said anything about these before

[sirwiggum]

I could do with resizing. Just ftpd it up to my webspace and left it.
Picture quality isnt great, taken on my Nokia E63 because the digital camera is in a drawer somewhere.

The clutch switch has really helped.

What I noticed was the old one was really quite "loose" for a better word, would spring in and out quite easily, whereas the new one was a bit more stiff.

Just in case anyone has this issue in the future, I googled it and a lot of people with HDi Picassos, Berlingos, 306s etc. have it, check the clutch switch. A £6 component.

[Welly]

Can you ask your neighbour to fetch the wheely-bin back in

[sirwiggum]

Yea those are the bins for the flats next to our semidetached.

Just to prove that SCZ exists

I've a sneaking suspicion that that Scenic has been abandoned too. On a mainland GB 'R' reg.

Few other jobs but at least I can change gear without looking like its misfiring.