I was there yesterday when Herbie's new Beetle turned out to be a right bugger to start (keep going whilst driving). Now, it's my fasty's turn.

I managed to get all the way to work this morning without incident and all the way home.

I live right across the road from a petrol station, so after turning the engine off I decided it was time to get my oil level checked, as I'd driven my first half tank and wanted to see how it was using oil (it's not, thank goodness).

But the dang thing just wouldn't start. I had to try again and again to get it to go, eventually catching it on the 10th or 12th go. I'd been priming the carbies with 0-3 pumps of the accelerator before turning the ignition, but that only seemed to help for half a turn of the engine before it was "chug-a-chug-a" again.

According to Cam last night, this is like vapor lock, where the fuel lines are too close to the engine and therefore hot and the fuel vaporizes before hitting the carbies.

What do you think might be the problem, and how do I go about diagnosing / fixing it?

Andrew

Hmmm, hot start probs. I'll point out the basics; in case you've missed the obvious.

One: Ignition too far advanced ("reverse torque" situation - this seems most likely from your description.)

Two: Overheating - Heads at too high a temp can cause "pre-ignition" - produces a similar situation to 'one'.

Three: Faulty points, condenser or coil - Ok, this one catches the best of us at times; it comes on so gradually we don't notice it until it's become serious, or we do a long run and it happens all of a sudden (check your plugs as well, especially if they've run unleaded or LRP.)

Four: Incorrect mix - most likely the same prob as two, would cause overheating, then the engine will "pre-ignite" when hot. Oxygen sensors can be found really cheap at a decent wrecker and a kit can be bought from Jaycar or Altronics to read it - a worthwhile investment for any home mechanic (if you're clever, you can put the display in the cabin and have a passenger tell you what's happening under various conditions.)

Five: Vapour Lock - actually rather uncommon in the stock VW (I know people who lived at aboriginal communities in the desert back in the 50s and that was about the only prob VWs didn't have. If this turns out to be the problem, you have moved the steel fuel line too close to a hot part of the engine, or you have an electic fuel pump in a similar location.

That's about the five most likely causes, sorry about the long message.

Thanks!

I'm the master of long messages, and this has really helped. I'll let everyone know how it progresses.

Andrew