Got me stumped

[Vintage man]

OK got a weird one,, 1600 engine running bad and connect timing light cylinder 1 and no signal. Test on other 3 cylinder all OK. Take out number 1 plug earth it and nice spark. Replace spark plug and no signal. Swop ht cables still no signal. Take out number 1 plug earth and timing light works, refit plug all a 100% then plug goes dead, remove spark plug for signal for light ok, refit plug and a 100% 5 minutes later dead again but the spark plug has spark outside the cylinder. Any ideas.

Tried new dissy with cap ect.
Tried another ht cable and same symptom.

In short when plug is out of the cylinder and timing light is still connected the light works ,reinstall no signal for light.
???

[retrovan]

sounds like you have Champion plugs, When I used them, always had one that die's

Replace all you plugs with new, and see how she goes.

Herman

[sean]

Faulty spark plug. Replace

[Vintage man]

Brand new NGK'S and did it with the spare plug.Will try new set.

[acpaterson]

could you be getting a short on that HT lead when the plug is screwed in? Maybe a new plug and HT lead.

[fig]

I find that NGK plugs have a very high failure rate out of the box. Since Bosch plugs are not easy to find (and can be manufactured anywhere, I've bought them marked Made in Russia, Mexico and India), I've been using locally made Champions without any issues. Champion was the plug recommended by VWSA in your owner's manual.

[Vintage man]

Hi ,tried another plug and ht lead still the same ,even swapped cylinder 2 ht with cylinder 1 ht same concern on cylinder 1.

[retrovan]

Hi ,tried another plug and ht lead still the same ,even swapped cylinder 2 ht with cylinder 1 ht same concern on cylinder 1.

The only way you can not get fire to only one cylinder is;-
Dead Plug
Broken HT cable
Cracked or carboned Dizzy Cap
Broken Plug cap

Is the plug wet when taking it out ?

Then you not getting compression on # 1

Do a compression test.

Herman

[Vintage man]

will do a compression test ,but even if there is no compression it should still fire (spark) so the timing light would work.My thoughts.Plug is not wet.

[Eugene]

Get another timing light...you have proven the plug as well as HT lead is fine, so would dizzy and cap be as you get spark. All that remains is the timing light. I know you say it fires on other cylinders but it is the only thing you have not swapped.

[Ricoffy]

Before getting a new timing light, do me a favour and check your points gap, especially on number 1. I don't know what dizzy you have fitted, but the POS dizzy's I had bought were retarded on some cylinders - the rotor shaft was bent. This caused erratic idling sometimes, misfires etc. Check that you have the correct gap on cylinder no 1.

[Vintage man]

Thanks every one. Came home fitted new BOSCH spark plugs and sounded great again then fitted new points. Even seems like the timing light was brighter.
Took bus for a lekker spin and seems smoother and stronger.
I think I could have over tightened the previous plugs NGK and damaged them. Now I'm a BOSCH plug fan.

[Donovan D]

I had exactly the same issue. Even tried different timing lights.
Engine ran smoothly and did not sound as if it was running on 3 cylinders. If I gave it a rev the timing light would come back on at number 1 but as soon as it went back to idle the timing light stopped flashing again. Also tried different leads and plugs without luck.
It seems to have sorted itself out.