ENGINE 'HUNTING' - No tick over!

[ClassicJagMan]

Hi all,
Any suggestions greatfully received.
My 1969 Series2 2+2 4.2ltr has not been started for a long time. Now it has got not tick over and when I manage to keep it running at about 2000rpm on the choke, the engine is constantly 'hunting' (it increases then decreases revs totally randomly on its own with no choke or throttle input!). As soon as I shut the choke off (when running temp reached) the engine just dies. Carbs overhauled a couple of years ago. Makes no difference if air filter removed. New electronic fuel pump fitted. New leads & plugs fitted. I am now lost for ideas. Help please!
Kind regards,
Andy

[mgcjag]

Hi Andy..if its not been started for a long time it probably needs fresh fuel and check out the filter....then its check the fuel levels in the float chambers....although the carbs were overhauled they will need looking at again....there is a section in the manual that explaines how to set them up....very easy to follow and at least you then know they have been set

[cactusman]

Check too that there are no inlet manifold side air leaks and the vacuum pipe that runs to your servo has not falloff or is perished. Major air leaks make idle very bad or impossible and it will be impossible to set up the carbs.

[ClassicJagMan]

Many thanks Steve and Julian for your replies.

Julian, does the vacuum pipe from the inlet manifold to the servo route itself via the bulkhead? There is a pipe next to a water pipe at the left hand side of the inlet manifold (back of the engine) that goes straight into the bulkhead.

Many thanks for your assistance,

Andy

[chrisfell]

As Steve said, its the fuel. After just a few months modern petrol looses its oomph as the volatiles evaporate away. Drain the tank and start again. Do not change anything until the fuel has been changed.

[ClassicJagMan]

Thanks Chris, I will try that first.
Kind regards,
Andy

[abowie]

Hi all,
Any suggestions greatfully received.
Andy

Easy. Get a competent mechanic familiar with the marque to sort it out.
She'll be purring in no time.

[ClassicJagMan]

Thanks Andrew,

Just the sort of reply I can do without!

I would have thought it pretty obvious that had I known of a competent mechanic familiar with the marque I would have tried that course of action in the first place!

[cactusman]

Hi Andy

Not sure with S2 cars. the servo unit will have a rubber pipe that runs back to the inlet manifold somehow. It may go via the bulkhead. Assuming you have flushed the fuel through, replaced the fuel filter and checked the plugs and points etc for dirt and grime and made sure there are no loose wires etc....the usual checks... then lumpy idle may just be an air leak....unlikely but not unheard of. And if you have a black after market rotor arm with a riveted brass contact bin it and get a red one from the distributor doctor while you are at it.

[mark10337]

yes, the vacuum should go via the lower pipe in the bulkhead on the S2.

[mgcjag]

Hi Andy....this bulkhead diagram may be if interest...viewtopic.php?f=4&t=10088&p=80553&hilit ... ram#p80553 .re Andrews suggestion above....you did say any suggestions welcom....its the Aussie humour i think

[abowie]

Thanks Andrew,

Just the sort of reply I can do without!

I would have thought it pretty obvious that had I known of a competent mechanic familiar with the marque I would have tried that course of action in the first place!

Just trying to be helpful. These cars can be complicated and sometimes seeking advice on an internet forum isn't the most direct course to getting your car running again.

I see you're in South London. I'm sure those in the forum near to you can suggest someone to take the car to who can sort it out for you.

Cheers

[ClassicJagMan]

Hi Guys,

Many thanks for all your suggestions and ideas, they were most valuable.

I thought I would give you all an update..............

After all your helpful posts, I decided to initially go down the fuel problem route. So, prior to draining the fuel tank and putting in fresh petrol I first of all changed the fuel filter in the glass bowl and........voilà! The car now starts on the button every time and has a perfect tick over! Just goes to show these Internet forums are a massive help!
Thanks again to everyone.

Kind regards,

Andy

[Mark Gordon]

Same thing happened to me when I bought my car, Andy. It wouldn't start when I bought it from an estate sale, but the executor (PO's son-in-law) swore that it had been running about six months prior to PO's death. I trailered it home, drained the tank, cleaned the sump and filter bowl and put in fresh gas. Bingo! it started right up and ran relatively smoothly; enough to take it out for my first run behind the wheel of an E. Any car that has been sitting for more than a few months without stabilizer in the tank should have its fuel system drained and cleaned whether it starts or not. You really don't want to deal with debris or varnish in the carbs. After that, you can start fine tuning with ignition and fuel delivery (carbs, vacuum leaks, etc.).

[ClassicJagMan]

Many thanks for your post Mark.
Very interesting.
Kind regards,
Andy