VW Craps out!! Advice please?!

[Matt84]

Hi all,

So, I'm in the dordogne in France at the moment - lovely by the way!

Was tootling along quite nicely along a quiet road around 40mph when the bus lurched, backfired (well, sounded like a bang) lurched again and simply cut out.

Never had any issues like it before, always been a really solid engine (1600tp, all stock - 34pict carb, oil bath filter etc...)

Went round the back to take a look and all looked well, I've got a gene berg temperature dipstick and the oil was no where near hot.

I thought it seemed like fuel trouble but I knew I wasn't out (had only brimmed the tank a couple of miles beforehand).

Tried again and was turning over really well but just wouldn't fire.

Took a look in my trusty John muir book and from the symptoms seemed like it maybe a stick float needle? Would people agree with this?

Gave it a tap with my screwdriver as suggested, tried again turned over for ages but eventually - fired up!

Left it running while I went to fetch my warning triangle (safety first) and it cut out.

Left it a few minutes, same again, eventually started. Got to my campsite (another 10km and ran great - just as before the trouble) booked in, went and had a pint (thought I'd earned it ), came back and eventually after much turning over fires up again.

I'm here for a few nights do you guys suggest I remove the carb - and if so, do what with it!!??

I like to think I know a bit about volksie engines but most of it is theory - until recently I never did much work myself but can now store the bus at home so helps.

Any theories/tips would be welcome, it's a long way back to the midlands!!

Thanks guys

 

[StuF]

If you can - check the leads and pop the spark plugs out checking each plug to see if they all look the same.
When it finally gets running are all 4 cylinders firing?
If all is good with the plugs and leads check for a nice strong spark when cranking - if all is good with leads and plugs/spark it will be fuel related

With the fuel - check to see if your filter is clear and not all blocked up.
Follow the bottom pipe from the fuel pump connected to the carb, disconnect and put into a bottle to catch the fuel - get someone to crank the engine and check for a good squirt of fuel as the engine turns. If all is good there then its time to start messing with the carb.

Post back on what you find

 

[Matt84]

Will do Stu, thanks for the reply.

It ran great between the issues which is why i thought fuel problem.

I had my fuel lines all changed before I came away, and they also drained the tank and cleaned the removable filter inside the tank (didn't know there was one!).
Could doing this have stirred up some rust in the tank and maybe it's just a bit of crud??

Will let you know how I get on,

Thanks again

 

[StuF]

Filling the tank from empty can sometimes stir up residue in the bottom if it gets really low.
There should be a fuel filter straight out of the tank outlet for this purpose - to catch it.
If it is partially blocked it could restrict the fuel flow causing it to be hard to start.

If the filter is ok - and you are still having issues it might be worth removing the carb and flushing it through with some carb cleaner.
Check the electrics first though.

 

[Matt84]

Hi,

So checked all the electrics, seemed normal and good spark. Pulled hose off carb and pumped some fuel out - seemed ok too.

Gave the carb a good tap all round - said the wife 'ahhh, it'll be fine'.

Started up no problem, drove the 25km and back to Bergerac for the day and didn't miss a beat!

Strange. Maybe I should think about a carb rebuild or just a remove and decent clean when I get home??

Thanks for your help Stu,

Matt

 

[Bigbear]

I had a similar problem a few years back, it would only happen if the engine was working hard (up hill etc) or after being run for a long time, turned out to be a faulty HT lead, you can test it and all would be fine, but if you removed the plug cap from the lead when engine was hot and tested again with multimeter the reading would be intermittent, caused a lot of lurching and backfiring.