Backfiring and refusing to idle

Well the suppressor doesn't seem to have anything to do with it, I have disconnected it and it is still backfiring and dying.

Perhaps its just as well it going in the have the engine looked at under warranty in a couple of weeks anyway.

It might be a ballast resistor rather than a condenser, in which case the coil will overheat without it, and give the symptoms you describe.

I fitted a new coil to the S2a along with all the electrical consumables prior to a long trip. The supplier gave me one from a later model which needed a ballast resistor, but I wasn't aware of this until the engine started to misfire when it got fully warm. Idling was fine, and it ran OK from cold, but once warm it farted and banged like it was going to die. Took me a while to isolate the problem as you tend to think that a coil is just a coil, and I looked everywhere else first. I finally sussed it when I touched the coil after a run and could have fried an egg on it. I replaced the coil with the old one and it has run fine ever since. I don't know which side of the coil the resistor goes, as I've never had one, but it sounds like that might be yer problem.

Well whatever side I connect the doodah to makes no difference of course running with it the wrong way round if it is a ballast resistor wouldn't help the coil I suppose, nothing for it but to put the original coil on and connect the doodah the opposite way to how I fitted it by guesswork.

Knowing my luck it is nothing to do with the coil at all, but I can only try I suppose.

Larry uttered summat worrerz funny about:

Has the Dizzy had a knock? Id it clamped tight? Is the Dizzy cap on tight? How about Dirt in the Dizzy cap , tracking in the Dizzy cap, Crapped up rota arm.

my money is on the timing / dizzy being out.

What bought it on? was it after a trip under the bonnet or just of it's own accord?

Lee D

If its one wire from the coil to the condensor which is screwed to the inner wing its an interference suppressor taking it off should make no difference . Theres a lot of stuff that can cause backfire type problems vacuum advance sticking ,dodgy capacitor ,crappy earth wire to distributer baseplate, points set wrongly - points are funny things they can change settings without help or even carb problems like excess fuel -- but if its under warranty get it back in pronto must confess tho' I didn't know S III 's had a ballasted coil I thought it was just the V8's Derek

Larry Have you checked your points gap? My IIA with a Ducellier (worse than Lucas in this respect IME) distributor will backfire like a gun going off when you lift off, once the gap gets down to about 5'ish thou or thereabouts, and won't tick over at all. HTH Alan

Turns out to have been a bad LT connection to the dizzy. It runs fine now, no longer sounds like I am mounting a single handed assualt on Kabul when ever I am slowing down.

On or around Tue, 4 Jul 2006 17:12:07 +0100, "Larry" enlightened us thusly:

oh yes, BTDT. sod to track down as well.

i drove a saab with a cracked head for a while. I quite liked the backfiring that did when i slowed down or reversed. people would almost dive for cover! :)

Im currently driving another saab with fuel pump problems and that bacfires a lot when youre coasting if it drops too lean. I've got to say im tempted to make it do it on purpose!