engine running on after off

why does the engine on my old G reg 1.7 Volvo 440 sometimes keep running for
a little while after the engine is turned off and the key out of the
ignition?

 

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.

 

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.

 

idle speed is about 800rpm when cold.

 

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 )

.............. 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.

: 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
:
: : > why does the engine on my old G reg 1.7 Volvo 440 sometimes keep running
: for
: > a little while after the engine is turned off and the key out of the
: > ignition?
: >
: >
:
:

 

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.

 

Bloke's a genius )

Si

 

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

Dave