Raunning on after ignition off.

[JohnK]

This is on a renault 18, 1.7 carb.

The car has always ran on after the ignition was switched off, sometimes (very roughly) for a couple of minutes!

I put this down to a carb problem as the carb seemed buggered, the mixture screw did nothing when turnt (co meter) and as far as I can see the timing is fixed.

Fitted a (brand)new carb, now the mixture screw works, although it doesnt give the adjustment I would expect and at first the running on stopped.

The new carb also has a 12v ignition switched solonoid to stop running on, however it has started doing so again, not as bad as before but doing it all the same.

Anyone have any ideas how I can stop this.

[Tom`s Supra]

Timing does this as well if its too advanced. Check the timing.

[JohnK]

as far as I can see the timing is fixed.



The dizzy appears fixed so I guess the timeing is.

[fredm]

Try disconnecting the wire to the stop solenoid on the carb whith the engine running, if the engine does not stop you have found the problem.

[Supragal]

Automatic or manual choke?

[JohnK]

Manual

[Chris Wilson]

Don't let it run on, VERY bad for an engine, put it in gear and stall it on the clutch.

Old Morris Itals, MGB's and other BMC B series engined cars had an anti run on solenoid that allowed a massive inlet air leak when switched off. You could adapt one of those. I think Renault do a thick head gasket to drop the compression, this helps stop it, too.