Car not starting. Backfire through carburettor.

[datzed]

Car is a mk1 Golf (76 automatic).

Went to start the car yesterday. It held idle for a few minutes then stalled (which it does sometimes when cold). After a few backfires through the carburettor and through the exhaust, it now cranks over but doesn't start. It cranks over healthily enough. Just wont catch at all.

Car is getting spark (new plug attached to lead shows spark)
Car is getting fuel to carburettor (unplugging line to carburettor shows fuel squirting).

What else could be the issue? It was driving fine yesterday. Haven't touched it since.

Tomorrow I'll attempt to pour some fuel down the carburettor to see if it starts that way.

Thoughts?

[sports racer]

Normally if it backfires through the carby the timing is off but you say it ran yesterday.

Check the rotor inside the distributor. Is it seated firmly? Hasn't broken and spinning on the shaft? Distributor hasn't shifted so the timing is out?

Is your distributor totally original - still using points? Sometimes the points gap shifts so it's not opening enough to spark properly.

Does it have an external capacitor? That might be faulty and not storing a charge between each spark plug firing. Wouldn't hurt to replace it or go breakerless points if you haven't already.

Cheers

Paul

[VR6 STORM]

Check the Cambelt hasn't busted or skipped teeth putting cam and dizzy timing out?

[datzed]

sports racer, yup still using points. I quickly visually inspected the inside of the dizzy and it all looks ok. Each plug is getting spark so I don't think its ignition related (will more carefully inspect dizzy tonight). I'll have a look at the capacitor situation tonight also. Thanks.

Check the Cambelt hasn't busted or skipped teeth putting cam and dizzy timing out?

Hmmmm good point. I did not check this. Might be difficult to check if its skipped teeth though (visually).

[abreut]

There's also a fuel cut solenoid on the carby. Its been a while since I looked at one, but if should be the only thing with a wire going to it. Check the wire hasn't fallen off, or has a bad connection. You should be able to hear the solenoid click when it gets 12v. Note: you can have fuel pumping up to the carby but it still has to get past this solenoid.

[datzed]

Thanks abreut. I've located the valve, and while the wiring seams a little dodgy leading upto it, I think its ok. I might rewire it and check it gets 12v.

[datzed]

Hmmm so the fuel cut solenoid is working fine. Cam belt also looks fine. The only thing I haven't checked are the fuses but I don't think there are any in their that will prevent this thing from starting. I'm almost at the end of my interest before I tow it to a mechanic. Will check timing and a proper look for massive vacuum leaks soon.

[GeorgeMK1]

Silly, but have u checked fuel is actually squirting down the carb?

[datzed]

Silly, but have u checked fuel is actually squirting down the carb?

I haven't, but only because its so bloody hard to see. I'll give it another go this weekend when there is decent light. Thanks George.

[VR6 STORM]

Check Dizzy timing by putting #1 piston at tdc on firing stroke, (both inlet and exhaust valves closed, take out plug #1 and carefully put a pencil in plug hole to check position of piston, but don't bust it off in there). If you cant get to see cam, then just took at dizzy rotor arm, it will be pointing at either #1 plug lead or #4 plug lead if you're on tdc of exhaust stroke. This will tell you if the ignition timing is in the approximate area for correct spark delivery to the relevant cylinders.
If you think its fuel related and its not over fuelling, get a mate to spray 'start ya bastard' or similar into the carb throttle body whilst you crank the motor. If it runs all the time the spray is being fed in, then its a fuel problem. Always suspect the ignition system is bad as this is often the thing that fails first. Is the spark a good strong one?