Intermittent start

[Tea]

Good evening all,

We seem to be having a little trouble with starting Boris (1968; 1098cc Saloon). We had no problems this morning, but by this afternoon he wouldn't start or turn over at all by turning the key itself. However, if I push pretty hard on the accelerator pedal at the same time as turning the key he starts (4 times out of 5). I've checked for loose connections without finding any and it's a brand new battery.

Any ideas what the most likely cause could be?

[David53]

When you say "push" the accelerator I presume you mean pump it? In which case the starting problem is fuel related, nothing to do with battery. If only happening when hot it could be vapor lock (petrol turning to vapor in the pipes/carby). I assume you are not using the choke when you start it hot?

[bmcecosse]

Sounds like an bad earth problem - the movement of the accelerator pedal is allowing an earth path THROUGH the cable - which will melt it in due course. Pumping the accelerator on an SU carb does precisely nothing for petrol flow......and the OP states there is no turning over until the pedal is pressed 'hard' . So check the earth strap at the gearbox crossmember, and best move would be to add an earth strap from the engine back to the battery earth.

[Tea]

That certainly is starting with zero choke when hot

Excellent, I shall check the earth strap in the morning.

Many thanks for the advice

[David53]

Ahhh I missed the bit about not turning over In that case yes, sounds like you're earthing when you press the pedal to the floor.