Practically Classics Forum

vintagemotor wrote:I had this issue on my Scimtar GTE and it turned out to be the ignition coil breaking down when it got warm under the bonnet. Like you, Id leave it 10 mins and it would start again. Worth a look at least?

New coil on it, as it was originally running the ballast coil and electronic points, now its running 12v.

Will double check filter direction but pretty sure fitted correct way round.

The common answer I seem to be getting from most sources is the rotor, so for the sake of a few quid I'll throw a new one on too.

hi mate,
i bet its fuel vaperisation,if its a converted p.i its probably a home made effort over the engine and if it starts when cool you should start there.the fuel filter seems about right i havnt seen one full of fuel.

cheers steve.

If my memory serves me right, I ran an earth lead from the coil clamp straight to the chassis (advised to do this my a Jag mechanic) and never had a problem again, I did this when I changed the coil.

A new red rotor arm arrived yesterday, so I'll fit that over the weekend, and see how things go from there.

I must admit the fuel pipe looks a bit Heath Robinson from the pump round to the carbs,



Copper?? pipe from pump, under alternator then over top of stat housing,



then to rubber hose, filter, rubber hose, and yes I know there are no clips on the pipes, it's on the to do urgently list!

There's an earth strap running from the coil mounting bolt on the block to the battery already. I did think some earth braiding had snapped looking down in the depths of the bay, but once I got under it I found it to be remnants of a snapped alternator belt.

Do the changes one at a time otherwhise you may get the car running better but be none the wiser at to what you have done to improve matters. I don't like the way that fuel pipe is routed over the engine right in the flow of hot air. I would reroute it around the engine bay, under the rad and then up to the carbs lessening the likelyhood of fuel vaporisation

That's pretty much how Triumph routed the fuel pipes- my Vitesse is similar, the only differece being that it runs in front of the thermostat housing rather than behind, so I don't think vapourisation is causing the problem. I'd be inclined to replace the flexible bits of the piping if it's of unknown age or origin.

Just because the coil is new doesn't mean it's not faulty- it might be an idea to drive the car until it happens again, and then whip the bonnet up quick and check for a spark by pulling off the centre lead from the dizzie cap and earthing it against the block, and also check wether fuel is being delivered-pull a pipe off and check if it squirts when being cranked, that should narrow it down a bit as to where you should be looking (obviously put the lead back on the distributor before you do this, sparks and petrol occuring at the same time should be kept inside the head, not outside ). The rotor arms tend to just fail and not work, they don't go and then come back but anything Lucas boxed is on borrowed time so it's worth fitting the new red one anyway.

I have generally done things 'one at a time' next on the list is the red rotor, not had chance to play this weekend, and it doesn't help its dark by the time I'm home from work

It would seem odd that it does exactly the same with a new coil, but as you say, anything is possible!

I know rotor generally just go, but taken from the Distributor Doctor site

Result - no sparks at the plugs. The situation sometimes rectifies itself on cooling, but then reoccurs with increasing frequency until the rotor permanently short circuits.

I live in eternal hope that this is the problem

I spent two miserable months with endless stalling and cutting out just as you describe. Problem eventually traced to sticking SU float needles. Seemed for all the world like an ignition fault. Next time just pop open the float bowls and compare/check the levels

G

Cheers G, I shall add it to the list

It would be odd for both float needles to start sticking at exactly the same time and if one carb was getting fuel the engine would still run just not very well. Can I be a heathen and suggest putting a known (or new) set of condensor/points in to eliminate the electronic ignition bits from the equation, one way or another? Perhaps try that after the rotor arm swap.