Run out didn't go according to plan...

[Gareth]

I had planned to go up to the Horseshoe Pass today and got halfway there when the Roadster started to misfire. I thought it was electrical as I've just changed the plugs, points, capacitor and rotor, and air filter but it idles perfectly but won't rev. Anyway, don't know how I did it, but I managed to limp almost home 10 miles when she finally gave up on the last few hundred yards. Got my mate to tow me back, oh, the shame...
Pretty sure it's the SU carb, possibly the piston sticking or the jet blocked. Hey ho, guess what I'm doing tomorrow.
I'll keep you posted. Gareth.

[b_caswell]

Re: Run out didn't go according to plan...

My first guess would be a rogue condenser try putting the old one back in before pulling the carb apart.

[romeks44]

Re: Run out didn't go according to plan...

In my case it was dirt collecting on filter in tank. After some time on highway i was not able to accelerate. Short stop was enough to reset (dirt fall down) but reappeared again after few miles.

[Gareth]

Re: Run out didn't go according to plan...

Weird thing is, when pressing the accelerator she splutters but the revs don't increase, and when I let go, she goes back to almost normal idling. And she starts up easily.

[getafix]

Re: Run out didn't go according to plan...

I don’t know the history of the car but it does sound like fuel starvation to me. I have experienced similar and a lot worse due to flakes of rust from the fuel tank in the petrol. Do you have an inline fuel filter? If so, I would have a look at that.
My car sat for a number of years unused and the fuel tank was rusty inside. My solution was to carry spare fuel filters and conduct routine filter swaps and on some occasions roadside swaps.

[Gareth]

Re: Run out didn't go according to plan...

Well that was interesting...the problem started before I had touched anything last week. Coming up to traffic lights etc, she would hesitate and when taking off would misfire a bit but getting away quickly seemed to work ok.
New points, condensor, plugs and carb checked and she was fine. Until yesterday.
This morning I discovered the SU carb piston was sticking, due to little burs on the edge of the piston. But still misfiring so I changed distributor and still misfiring. Points and condensor changed yet again and she's now ok. Condensor is main culprit. To make things easier in case of another breakdown, I've made up a spare condensor on a lead with a crocodile clip either end, so the old one can be cut out and the emergency one just clipped on in the engine bay anywhere to get me home.