STARTING PROBLEMS 3.4 S TYPE

[Br1970]

Hi,

I have a 1964 S type 3.4, I have a couple of problmes which may be linked and I would welcome your advice : Car starts from cold no problem, drives fine and runs well. At times when I stop the car however and try to restart it it is as if the car wont fire or has no fuel supply. Yesterday for example I took the car for a run, stopped at the shop for about 20 minutes and had to give it several attempts to start when I came out, when it did start it was running rough and only ran smooth after working the throttle in & out a few times, then when I drove off at lower revs the car was " jerking" , again I pushed down the clutch and reved the engine and it reved smooth. Drove the car about ten miles on the motrway, ran fine. Got home and while it was idling for a few minutes in my drive way it cut out, same thing again starting it, got it satrted and moved it down to outside my garage, again it cut out. I put in a different ignition coil & the car started and eninge ran fine ( car stationary) for a few minutes but again cut out. I removed one of the plugs and connected it into it's HT lead and got my son to crank the engine, there did not appear top be any spark , I then re-connected back the old coil and after a 15 minute break the car started. Do you have any suggestions, I recently had the car serviced and had new points fitted

Please help ! & thank you for your assistance

Kind regards

Pat

[Martec]

Hi Pat,

Was the car OK before the service, if so what was replaced?

There has been a problem with 'new' rotor arms breaking down when hot and working when cooled down, I carry a few just incase.

New points are made with a plastic 'foot' to run on the 6 lobe cam, they wear quite quickly and close up the gap and so retard (I think) the ignition. As the plastic hardens after about 500 miles then the contact faces can be polished with an oil stone and it will last longer. Electrionic ignition overcomes this.

Sometimes the heat sensor that operate the choke carburettor gets tired and may stick on leaving the choke open (you can hear the hiss when it is in operation). If you think it is open then pull the wire off the sensor in the inlet manifold and see if it runs better. This applies to an SU set up on a MkII.

Best of luck

Brian

[Br1970]

Hi Brian,

thank you for your reply, the service was just routine, points etc. replaced, I did have this problem before the service some time back but it only happened once or twice and the car ran o.k after that. No rotor arm or anything like that was replaced. The choke hissing noise is not present when the problem arises.

I have wondered since would it be the distributor, either the mechanical or vacumm advance ? I will try cleaning the facees of the points also.

Thanks again for your help

Regards

Pat

[ollyw750]

I would also check that the condenser is earthed properly. I had a very similar issue a few weeks ago and found that the car started fine, then cut out ofter a few minutes, or whenever I arrived at a junction and let the car idle. Turned out I had not tightened up the condenser screw and it was able to rattle. This would also explain the intermittent spark.

One other thing. It is possible that the carb jets are worn and allowing fuel into the carb throttle body while the car is stationary. This will then effectively flood the carbs when hot, and will not be apparent when cold as the extra fuel probably aid the cold engine.

Hope this helps

Oliver

[Br1970]

Oliver,

Thanks for your reply