Dip clutch, engine cuts out!

[NormW126]

Having a bit of a problem with my W126, 300SE manual. It happened at the start of the year, then seemed to go away on its own, and now it's back! Basically when I am driving and I come to a stop (i.e. I dip the clutch) the engine often cuts out. Sometimes the revs dip down, then come back up to normal, sometimes the revs dip down and the engine cuts out. It always starts right back up again though. Seems to happen more when the engine it warm.

Distributor cap, rotor arm, ignition leads, fuel filter and air filter are all fairly new.

Anyone have any thoughts?

 

[renault12ts]

Clutch thrust bearing?

 

[lxi]

Find an empty car park - get the car rolling in gear, then knock it out without touching the clutch (brake per normal though) so the engine is under no load - see what the revs do then - if the same, then it's not clutch related

 

[renault12ts]

^ what he said, but if the engine does nothing wrong, then it is the clutch.

 

[lxi]

Basically when I am driving and I come to a stop (i.e. I dip the clutch) the engine often cuts out.

Just had a thought - you say you dip the clutch - do you take it out of gear or leave it in ?

If the latter, then the clutch may not be fully disengaging & if it varies as you say, then perhaps master or slave cylinder on its way out.

The bite point of the clutch would help diagnose - if it starts right at the floor then that could support the theory

 

[FazMan]

With some engine managment systems the ecu control is removed on tickover, problems like this can then arise due to things such as a sticky idle control valve (just needs cleaning) vac leaks, etc.

Worth trying revving the car to 1,500 rpm for a few seconds and then removing your foot completely from the throttle and seeing if the car returns to idle correctly.

Just to eliminate possible problems as with the comments above.

 

[stwat]

Check the Idle Control Valve as stated above. Also check that the plate in the air Flow Meter is set correctly and not catching as it returns to the top at tick over. And also check that the throttle micro switch on the throttle body is being clicked when you release the accelerator. if not then the throttle cable will need adjusting. The switch it's self may also be faulty.

 

[NormW126]

It happens when the car is still in gear, but clutch is dipped, even when coasting rather than actually stopped. So if it happens when I'm coasting I just let the clutch up and sort of bump start it.

I actually have a spare idle control valve so could maybe give that a go first.

Annoying it is very much an intermittant fault. Sometimes the car drives perfectly.

 

[NormW126]

The other issue I have is that there is a bit of a stutter / hesitation whilst driving. Again rather intermittent but seems worse when accelerating.