Non-T25: Buggy engine running problems

[weimarbus]

and another

[horizontal kipper]

Are you running a modern crap version of the 009 dizzy by any chance? i had this problem once on a bug , the points gap was correct i checked the dwell reading which was well out rechecked points gap on each lobe of the dizzy with feeler gauges 3 of which were the same 1 was out. swapped it over for a svda dizzy problem went.

[horizontal kipper]

Are you running a modern crap version of the 009 dizzy by any chance? i had this problem once on a bug , the points gap was correct i checked the dwell reading which was well out rechecked points gap on each lobe of the dizzy 3 of which were the same 1 was out. swapped it over for a svda dizzy problem went.

just reread post realised you running a vacum dizzy. too much cider.

[CJH]

Actually, no, it's not a vacuum dizzy. Not sure what model it is though - I'll check today. That vacuum pipe I mentioned simply links the two inlet manifolds. I assumed that was something to do with helping to balance them, but I'm wondering now if the previous owner has replaced a vacuum dizzy with a non-vacuum type, and linking the inlet manifolds was the best thing to do with the left over spigots. Would an original 1967 Beetle have had a vacuum dizzy?

Last few jobs this afternoon before my mate can finally take it for an MOT, hopefully:
- Fit the new (black!) tinware
- Fit a new intake manifold gasket on the other side (just in case)
- Fit the new solid state regulator (and earth it - currently mounted to the fibreglass body )
- Reassemble the dynamo and fan, and add a dedicated dynamo earth - the dynamo pedestal looks a bit corroded, so the earth through there won't have been great - I guess it might also have been encouraging that pedestal corrosion.

[horizontal kipper]

Yes an original 67 would have come with an sva dizzy but would also be a single port motor so as yours is a twin port miss match i would still bin the 009 and fit a svda.

[CJH]

OK, thanks. I guess we'll get it on the road and see how it performs. I suppose a vacuum advance dizzy will be better if the advance curve matches the engine characteristics better, but with this modded engine is there any guarantee that the dizzy meant for the original engine will be any better than the non-vacuum type currently fitted?

[horizontal kipper]

True you could try both but be sure to use a strobe and check the max advance as not knowing what the vacume from the carbs you are using will be pulling the motor could overheat.

[CJH]

Fitted the new regulator, and the charging circuit is working fine now.

But fitting the new tinware meant removing the inlet manifolds again, and now the non-firing cylinder number 2 is back. Might be dirt on the gasket face, or maybe those paper gaskets weren't suitable. Or maybe the blasted tinware meant we didn't fit the manifold properly! It certainly got in the way, and even makes putting the spark plugs in a pain in the neck. Anyway, we're going to get a couple of the metal crush type gaskets and recheck everything.

We couldn't get the engine to start at first, so we went through the usual diagnostics. The spark in number 2 looks weaker than number 4, but I don't see how that can be so maybe it was just the light. But I did notice that it's a 009 distributor, so maybe we should check the points gap on all four lobes.

[CJH]

Are you running a modern crap version of the 009 dizzy by any chance? i had this problem once on a bug , the points gap was correct i checked the dwell reading which was well out rechecked points gap on each lobe of the dizzy with feeler gauges 3 of which were the same 1 was out. swapped it over for a svda dizzy problem went.

My mate says he's checked the points gap on all four lobes, and there is a bit of variation - maybe 0.1mmm, with the biggest gap on cylinders 1 and 2. Could this account for the misfiring cylinder 2? What does a bigger gap do to the spark? Could it account for the apparently weaker spark?

He's considering swapping it for a new SVDA distributor. Do you know how the two vacuum spigots, one on each manifold, would connect to one spigot on the dizzy? Would it just be a T-piece?

[ozzi_in_the_uk]

Are you running a modern crap version of the 009 dizzy by any chance? i had this problem once on a bug , the points gap was correct i checked the dwell reading which was well out rechecked points gap on each lobe of the dizzy with feeler gauges 3 of which were the same 1 was out. swapped it over for a svda dizzy problem went.

My mate says he's checked the points gap on all four lobes, and there is a bit of variation - maybe 0.1mmm, with the biggest gap on cylinders 1 and 2. Could this account for the misfiring cylinder 2? What does a bigger gap do to the spark? Could it account for the apparently weaker spark?

He's considering swapping it for a new SVDA distributor. Do you know how the two vacuum spigots, one on each manifold, would connect to one spigot on the dizzy? Would it just be a T-piece?

Yes, you would need a T-piece, as the vacum ideally needs to be a balanced system for your vacum advance to stand any chance of performing to it's potential.

Ozzi

[marlinowner]

Variation in points gap will cause variation in spark timing, not strength. Wouldn't have thought it would be enough to cause a misfire though.

[CJH]

Thanks both - I guess we should wait to see where we stand once the new inlet manifold metal crush gaskets are in.

Looking ahead, is the SSP SVDA dizzy from VW Heritage ok?

[CJH]

The new metal crush gaskets are in, and we even used a thin bead of Dirko Grey (cold vulcanizing, silicone-rubber based) to make absolutely sure. Still got the misfire. And it needs highish revs to keep it going. I'm pretty sure the timing is spot on (7.5 BTDC) because when we previously had it idling at a sensible speed we checked and adjusted it just so. It beats me what could have happened since then to prevent it idling at low rpm, but of course while it's running fast it's difficult to check the timing, but this evening I attached my timing light to each plug lead in turn and as near as we could tell there's no big difference between the cylinders (apart from 2 and 4 being 180 degrees out of course).

It's also very hard to start first time. Once it's run for a minute or two, it starts much easier.

So our next step is going to be to replace the distributor cap and rotor arm, although as said earlier, they look good. That'll be all new electrics apart from the coil.

We got to the stage this evening where we'd adjusted the throttle stops so that we could start it without the accelerator. It would run smoothly for 10 seconds, then start popping from the right hand exhaust, then the revs would drop and it would die after about 20 seconds. When it misfires, or pops, there's a hint of white smoke at the tip of the right hand exhaust, like unburnt fuel perhaps. We're wondering if the mixture is way off on the right hand carb (they've both been off and cleaned out and reassembled). We're considering swapping them over to see if the misfire moves to the left bank. Is there a standard starting point for adjusting these carbs (e.g. wind the screws all the way in then back them off three turns - that sort of thing)?

Any ideas what we could try next?

[PetenAli]

So our next step is going to be to replace the distributor cap and rotor arm, although as said earlier, they look good. That'll be all new electrics apart from the coil.

As well as the coil the other key ignition part is the condenser. Only then can you say you've replaced all the ignitition side.

Sounds like you could do with a copy of the John Muir Bible. Apart from just being very useful its also a good read. Look here: http://www.amazon.co.uk/Keep-Volkswagen" onclick="window.open(this.href);return false; ... 1566913101

PS Its a pretty looking buggy - thanks for posting the pics!

[weimarbus]

As per your previous post where you said it was running well, if the only thing that you have done is to remove the manifolds to install new tin ware I would suspect that the tinware needs trimming back around the manifold seat to allow it to fit and bed down correctly, or is the fan shroud touching the carb and tilting it preventing a seal?