Strange car problem!

[alivin]

"1977 MkII Popular Plus 1100"
Sweet, the very same model I learnt in.
I've found in the USA when you say escort people think of a slow comuter (POS). They've never heard of the old escort mexico & their ilk. Screamers all of them. I had a lot of fun in escorts wink, wink.

[caddmannq]

Jonty, if you could see petrol squirting into the carburetor when you tweaked the accelerator puump, then the float boal wasn't dry. There was fuel in it. Now if at that time, after tweaking the accelerator & seeing the fuel squirt & cranking it, it didn't start, then the problem is electrical. An 80F day isn't enough to vapor lock any car I've ever seen.

However:

Ignition coils can fail in "fits and starts" if you know what I mean. It runs, it quits, it runs, it quits, it runs poorly, it finally dies.

Your car may have a bad ballast resistor. If it dies again, try jumping across it. It should run quite a while with a jumper on the ballast, but it's bad for the points. A bad ballast won't usually prevent it from starting, but it will die as soon as you release the key.

Ignition switches are prone to wear out, & that might cause the loss of primary voltage to the ignition coil. With the car running, try wriggling the key switch all about & see if it cuts out. You might consider taking a jumper with with you, so you can bypass it if the switch fails unexpectedly. That bypasses the ballast, BTW, so it's bad for the points too, but it will run like that quite a while.

Some cars don't have a fuse in the primary ignition circuit. A short circuit in the primary wire could be intermitant, somewhere between switch & ballast, ballast & coil, coil and starter, or coil and distributor. (The ballast or distributor itself could be shorting too.) Bumping the car uphill with the starter would torque the engine hard against the rubber mounts, and might have dislodged such a short. If a short develops, & the engine dies, putting a jumper to the coil won't work, as the circuit is still bled to ground somewhere. You should detatch the primary coil wire first. (Did you smell any wires burning?)

I had a car that died once just like that, and it turned out that some idiot (me) had dropped a small screw into the open distributor, where it rattled around until it eventually shorted the points to ground.

Finally, is the top of the coil clean? Dirty = bad.

[Jonty]

Thanks to everyone who has offered suggestions to this. I am 99% sure it's vapour lock because
1) Last week was unusually hot with the weekend the hottest for May for 50 years.
2) Yesterday the atmospheric pressure was strange with thunderstorms finishing the day.
3) The car was in my garage for the whole week unused with no ventalation. The garage has an asbestos roof and it gets very hot, in the summer I open the window but not last week.
4) I started to use a different brand of LRP petrol the other week, last filling up about two weeks ago (the tanks almost full btw). As there aren't many old cars around where I live the call for LRP is small so it was probably 'winter' grade fuel in the stations tank.
5) I noticed that the spark plugs were bone dry even after several goes at getting it started and pressing the accelorater, surely that would have made the plugs wet?
6) I've had bad points, distributor cap etc in the past and the car misfires etc., nothing like what happened yesterday.

caddmannq - I keep the coil and electrical stuff clean but have taken on board what you say about the ballast resistor. There were no funny smells or anything unusual at all.

alvin - you originally from England?

wju425 - I still can't see how the condensor could cause this problem. The roads were dry and I had only driven a short while when it happened.

kingofpain, brainchild and RedFury - I agree. The crayon tip is good, maybe I'll try it but I really think the problem won't happen again for a time. I might be wrong but I'll let you all know if it does!

Thanks again guys.

[Jonty]

Just a little update on this.

I took the car to the garage this morning for it's annual government MOT test and it passed.

Everything is fine with it.

[RedFury]

Good to hear. I'll agree with Cadd though also, sometimes an intermittent grounding problem can be strange like he described.

I had a VW Scirroco that would die for no reason, and then it would either stay dead for a couple of days, or would start up after I'd lifted the hood or something weird like that.

Turned out to be the signal lead from the distributor had an internal break in it and the wire had to be replaced ( or put into the right angle to reconnect it ). Would have never found it without diagnostics.

Best advice I can dish out now is to just remember the circumstances around this, and plug them deep into memory for recall if your car ever dies like that again. Then, if the circumstances are similar or the same, you've got an idea of what to look for.