Author Topic: AC Saloon running rough!  (Read 12985 times)

Julian

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AC Saloon running rough!
« on: June 23, 2008, 19:48:28 »
1954 four door saloon.  OLW 764
   The old girl's going back on the road after a 9 month lay up.  The engine lacks all power under acceleration, and coughs and splutters and seems to be missing on at least one if not two cylinders.  On tickover and while cruising, she's as sweet as a nut!  The problem gets worse as the engine warms up.  It almost feels like the choke is permanently out!
   I've cleaned and reset the plug gaps, checked the points gap, and cleaned the fuel pump breaker points.  The HT leads seem to be a loose fit on the plugs, but I would have thought that there would either be a spark or not[?].
   Is it likely to be a carb problem, and is this a "user serviceable" issue?
   I'm a semi-competent amateur mechanic (probably the worst kind[:I])  Anyone got any tips on successful tuning of triple SUs, or am I barking up the wrong tree?

cassiewoofer

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AC Saloon running rough!
« Reply #1 on: June 23, 2008, 19:56:20 »
wish I could help ya mate! but i've not got that far yet! and I can't get a spark at all!!!
   good luck with it anyways. looks like my petrol pump's not pumping, and there's quite a bit of corrosion on the HT socket in the coil. Interesting problem anyway you've got there!
    Keith.

Julian

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AC Saloon running rough!
« Reply #2 on: June 23, 2008, 20:11:26 »
Thanks for that Keith, my petrol pump sticks when the car has been standing for a while.  I take the cover off, reassemble the electrical connections, and with the ignition on, move the breaker points backwards and forwards a couple of times with an insulated screwdriver or plastic pointy thing (one of Action Man's oars is about perfect).  Hey presto..... click click click.  Probably really needs some proper maintenance though.

cassiewoofer

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AC Saloon running rough!
« Reply #3 on: June 24, 2008, 17:28:11 »
Have you checked the fuel filter? just a thought,
   Keith

cassiewoofer

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AC Saloon running rough!
« Reply #4 on: July 02, 2008, 10:30:14 »
Any luck with your problem yet?
    Well I finally got the thing running, and she's ticking over very nicely.
   Anyone know where I can get some new HT leads? I think the insulation is degraded! It looks fine but I keep getting quite a zap when I grip them hard!!!
   
   Keith.

Robin A Woolmer

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AC Saloon running rough!
« Reply #5 on: July 02, 2008, 11:05:04 »
You should be able to get them from your local motor factor, you can puchase it by the length & cut it to the various lengths needed, i think it is 7mm diameter but if you take your old leads with you they will give you the correct material
   Robin

cassiewoofer

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AC Saloon running rough!
« Reply #6 on: July 03, 2008, 10:21:44 »
That's great, had no idea it was that simple!

1936ACE

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AC Saloon running rough!
« Reply #7 on: July 03, 2008, 22:32:35 »
Recommend that you use traditional type of HT leads with wire in them instead of the modern stuff.  One advantage is that you can solder on spade terminals for the spark plugs to give a good connection.  However if you do so and are running a postwar engine watch out because the cross pipe for the choke assembly is a bit close; better to insulate the pipe to avoid the risk of a short circuit.  Good source for electrics for classics is Auto Electric Supplies.
   
   Mike

cassiewoofer

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AC Saloon running rough!
« Reply #8 on: July 04, 2008, 11:37:57 »
Thanks for that, will probably use modern for now and get some traditional type when I'm not so busy.
   
    Sorry Julian, I seem to have inadvertantly hijacked your thread!
   How's your acceleration problem, any joy?
   
   Keith.

davrix

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AC Saloon running rough!
« Reply #9 on: September 08, 2010, 18:48:54 »
Hi Julian,
   I've just read your thread on this forum; I would assume you may have fixed things by now ... however if not it could be your silencer causing the issues. We has the same problem last year on a buckland, started fine, tickover like a dream, move away and try accelerating or a hill and splutter splutter to a complete stop. Would then start and run fine ..  sequence repeated again and again.  Turns out the silencer had disintegrated internally and was causing a blockage on the exhause ; huge back pressure which would stall the engine on load !
   Fabricated a new silencer ( the rear one with the two lugs to mount to the chassis, and all is well again). Good luck  David