engine running on after off

probably idle speed is too high, may need a tune up or even a decoke.

MrCheerful

The timing is out. You need to have this redone. If your not sure why its doing it then you probably not know how to fix it. Take it to a garage and ask them to check the timing.

"Dubster" mumbled:

Out of curiosity...how does the timing affect the running of the engine once the ignition's switched off?

Running on 'cos of a coked up head and/or idle too high I can understand. Unless you mean that 'cos the ignition's retarded the exhaust valve's a lot hotter than it should be.

If it's carb, that'll be the fuel cutoff solenoid.

It's probably "dieseling" - there will be lots of lovely carbon on the pistons, which gets very hot. When you switch off there's still enough heat in the carbon to ignite the fuel vapours which are still hanging around. Is it very lumpy when it runs on?

Give it a bit of a thrash, I would, or treat it to some Redex in the plug holes overnight. I have heard that Redex might affect older engines adversely but it's a lot easier than decoking!

Si

Most likely cause is an air leak, check all the piping around the inlet manifold. You will probably find a split or disconnected pipe.

Hi "Two Sheds",

Your post made my day. You must be a Monty Python fan............. and a UK resident? or do they still flog Redex somewhere else? I used to add it religiously to the gas (sorry... petrol) at every fill-up in Elgin, Morayshire, Scotland. I believe it was described as an "Upper Cylinder Lubricant". Some enthusiasts even rigged up an "in-cab" device to feed the stuff to the motor at the touch of a button.... Our '51 Jowet Bradford Utility needed all the help available to its 1 litre twin cylinder horizontally opposed engine........ Current chariot, a '93 240 Classic wagon is managing quite well without it, after 200 000 Km.

Andy I.

Hi,

I think it probably is due to some carbon built up in the cillinders/piston etc. When it is glowing, it can ignite the fuel again and keep the motor running shortly. Use a additive you can poor into the gasoline, and then make a long drive so the motor really gets warm - that will burn it away.

But a Volvo should not have such problems. Do you make very short drives, or did you not replace your airfilter? The gasoline/air mixture is probably too rich. You can see that by inspecting the spark plugs. They should not be black, but dark to light brown. Or just look in your exhaust at the back of your car: does the inside look black and fatty, or brown, or even lighter?

Regards,

Pieter

Of course :o)

............. and a

I'm on the bit that Kent County Council are thinking of selling to France: Thanet (a joke, I assume, but you never know with KCC).

I believe it does some good in some cases. Certainly makes a good ol' cloud of smoke which upsets tree-huggers for a 3 mile radius.

Si

it's coked up if it's injection, get hold of some 10k boost if it's crab then pour some redex into the inlet and watch the neighbours ring the fire brigade :) seriously

Thanks for replies - has been used for lots of short local journeys e.g. 4 miles x 4 daily plus 9 x 2 daily. Prob chocked up. Will check for pipe damage and condition of plugs next weekend when I have more time. prob grab some Redex and upset the neighbours as well. I do know that the heads are a bit coked up as 2 years ago the head gasket went - I saw the heads when I went to the garage one day and they were interesting to say the least. Must blast it somewhere soon too on a ling journey when things are checked and sorted.

To stop the smoke giving annoyance drape a wet sack over the tailpipe so that the exhaust fumes have to travel through the sack to get to the atmosphere.

Cheers, Peter.

: >

: :

Take one carbon encrusted valve and one petri dish of Redex, stand the valve in the dish for ten minutes then remove and regard how clean the bugger now is. :)

atmosphere.

Bloke's a genius :o)

Si

Wish I had thought of that, after I did my Landrover and smoked the whole village for an hour !!

Dave