I developed a hideous backfire/miss under load.

I used to get some hesitation due to the carb needing a bit more tuning, but it never backfired like this.

I resetted the points, they were closer than they should, and then i retimed the ignition to the usual 7.5 degrees. All spark plugs were a dry and sooty (rich at cruising), the gaps were all right and i rubbed off the soot.

I did notice ignition lead on cylinder 2 was busted. When i pulled it off the spark plug, a small cylinder with a coil of wire wrapped around it (resistor maybe?) fell out onto the grass. I used plyers to pull out the spark plug clip sitting on top of the spark plug that came from the lead.

I'm on stradbroke and will baby it home (in all its popping glory). Could this be my reason for it backfiring? I'm thinking, it misses or causes poor ignition, causing a delayed flame front getting into the exhaust or putting unburnt air/fuel mix that ignites with the hot exhaust?

By the way, it was doing this instantly after a full hose down after a beach run, i let it sit and dry over night, then the next day it was running fine again. alot of water got into the engine bay, to wash off all that sand/salt that went in there.

Next day it ran fine.

And then today (few days later), this develops instantly after pulling over to check oil after a nice run through some bush tracks. started having a general misfire, then backfire under load.

Definately could be the cause. Try getting some electrical continuity in the lead to get you home.

VW had wire spark plug leads originally and used resistor spark plug caps and resistor rotor to stop electrical interference..

Maybe You had silicon leads??? or the old carbon leads??
YIKES...

You can easily break the conductor in silicone leads just by pulling on them off the coil or spark plugs
{I did with brand new ones]

I always carry a spare long spark plug lead and spark plug and resistor cap just in case... [along with other spares]

sounds like the water was conducting the current and earthing out??

I hope You can jam the lead over the spark plug end...

best of luck getting home...

cheers

LEE

If you have been idling around a lot on the island are you sure that the plugs are not just fueled up and not firing properly .
Just give it a good clean run up the main road to Dunich and it should clear itself if thats the problem and wind your idle mixtures in a 1/4 turn or so

I think the end broken off a high tension spark plug lead would be the answer....

Also He has checked and cleaned all the spark plugs...

back firing under load is almost certainly a break down in ignition.

VW system is so simple just check everything on the ignition.

He already has found the end broken off number two high tension lead....

No spark will certainly lead to a misfire....

LEE

haha ok, didn't see that

Thanks for all your help guys, the baja is back on the mainland safe and sound. But the story unfolded a bit differently to plan ,

It was an hour and a half left before the barge was to come in and I went to reverse the car up the drive way. It would turn, but wouldn’t start!!! Gah! Plenty of fuel, coil getting 12 volts… Even sprayed in some starter fluid. Not a pop. Obviously a spark problem. Even took the rocker cover off to see if the cap wasn’t on 180 degrees after stuffing with the ignition leads. Checked the points again to make sure the hold down screw still held the points at the right position and the dissy cap and rotor looked fine.

In confusion and in my panic, I simply didn’t have time to stuff around with dissy internals and swapped the SVDA that’s only been used for 150km’s or so for my chinese 009. A few kick backs I retarded the ignition and it came straight to life. Started like a dream. Got my timing light out and wow, the back firing has disappeared too! The hesitation is still there but is sooo much smaller now. A new set of ignition leads and hopefully its all gone. Off the line its now quite a pleasure to drive.

HA! Just on my last day at straddie, where offroading on the beach was crap & risky with low down hesitation making it even harder with rookie beach driving the baja starts to drive nicely. TYPICAL!

Ah wells, was a nice drive home. Will have to go back to attempt to conquere main beach again. Sand was very soft at the enterance due to the November dry spell, A Landcruiser troopy that got stuck minutes before us got us out of the enterance safe and sound. Will be sure to make certain of 100% good running next time (was silly). Conquered Flinders though and certainly learned a lot in the process.

Lee Thanks for the help and pics mate. I got silicone leads. They are brand new, well I had em for years, but have used em for only 800km’s or so. I rekon it was the removal off the spark plug in the past that busted it.

Hey Chris. I would be checking to see that the vacumn port in the Stromberg carby isn't blocked.

It sounds an awful lot like the SVDA wasn't getting any vacumn and that was the cause of your massive flat spot because you were only relying on the mechanical advance of the dissy when it kicked in. Swapping in the 009 would have solved this because it's purely mechanical.

Just a thought and maybe something you could check out.



Smiley

is it an original svda or new chinese $50 one ? had problems with every cheap vacumn dizzy ...bin it

Thanks Daniel. will have to check. Was definitely a chinese job Klaus, lol probably the answer right there too. My chinese 009 seems lucky enough to be running well

Well, i assumed my svda was chinese, given the price was dirt cheap from vollks.com.au, $50 or around that.