What could cause the engine to stop after about 20 mins of driving then after about 5 minutes start up and then continue to cut out every 100 metres, wait 5 mins then 100 metres and so on?? I have got a new fuel pump (previous one only a few months old) and filter. Checked the carb (chinese version of a Solex but with all the jets etc changed to ones from an old Solex I had). To me it felt like fuel not getting through but I have a new coil now, points are opening fine and starting from cold couldn't be better. A new battery has been fitted and the wiring checked from the key right through to the coil and down to the pump. Surely it couldn't be the switch itself as that's the 2nd one in about 2 years and why would that cause stopping and starting? The only thing I haven't changed is probably the cheapest and that's the condenser but everything I've read doesn't include these symptoms. When I initially put the new battery in it ran fine for about 2 weeks then out of the blue this sh*t started up again. Please help as I want to drive without waiting for something to happen If nothing else it's very embarrassing sitting at the side of the road waiting for it to start

have you cleaned all the filters and emptied the fuel tank??

my ute had prob like this and found the carbie to manifold nut was loose (back one)

then if its a ute the fuel filter has to be lower than tank level

make sure esp in hot wthr all the connections are air and fuel tight!!

New filter and the tank was emptied. Not a trace of dirt was seen. To me it definitely felt like it was a fuel blockage but I'm at a deadend!!

Is the fuel tank vented? Dave

The tank because it's for the FI has the fuel condenser (?) system and the charcoal canister but what you're suggesting was one of the first things I thought of and disconnected the pipes so it just vented inside the boot but it was no different. The gauze filter in the tank is still intact and in pretty good nick so nothing is blocking it. I've tried everything I can think of so far, I've even tried running a cable direct from the battery to the fuel pump (not recommended!) just to see if that bypassed a problem and the same cable direct to the coil but both times exactly the same symptoms. Maybe dumping this Solex lookalike could be the way to go as I've tried/replaced everything else!!!

Do you have a blocked steel fuel line?
Have run a new steel line near the rear heater boxes or somewhere where there is excessive heat like under the pan?
Does it run from cold every time and the stop?
Basically a blockage in the fuel delivery or excessive heat vapourising the fuel.

Best to start by stripping the carb down and giving it a good clean out with carb cleaner including all the galleries and removing the jets to clean them properly.

Then flush the fuel line through with some kind of fluid like carb cleaner or at least with compressed air.

Check the inside of the tank doesn't have loads of sediment in it and clean if necessary.

Lastly, check the fuel tank cap and depending on year of manufacture it can either be soaked in Kerosene overnight to unclog the horsehair in the cap or on later model a small additional vent hole can be drill in the top of the cap.

If you clean the entire thing thru then that will rule out the fuel system and leave you with an ignition fault.

Cutting out so often could be the coil overheating cos even though it's new don't mena it's good quality these days.

And I would definitely have the tank venting outside the boot, not inside
Cheers......Wayne

I've blown the fuel line through already, I may try using the return fuel pipe if possible as that's now sitting redundant (it was fi).I think everything else suggested here I've already done, the coil which wasn't very old I replaced just in case,the same goes for the battery and electronic fuel pump so if nothing else I do have spares! I will remove the tank (again!) and try carb cleaner through the pipes then if it still plays up the last thing will be to rebuild an old Solex.

I had one once with a faulty Tacho. Intermittent cutting out etc. Disconnected the Taco from the negative side of the coil, fixed.
Lots of things can heat up, fail, cool down, come back. Coil, condenser, fuel pumps, injection components.
Try a squirt of fuel down the air cleaner, if it starts it’s not ignition related.
Good luck
Tony

Once had a intermittently sticking fuel pump pushrod (where it goes through the plastic block I suppose). It would run normally when cold, but stall sometimes, only when engine was quite hot, in slow traffic. At higher speeds all seemed OK! -- it seemed to be due to the heat building up on top of engine/around the pump. It always took a while to restart when holding up the traffic; the seemed to run noramlly for a while again -- does sound similar to your first post.... i.e.
The symptoms are similar to fuel vapour lock, but take longer to start and then come and go quicker.

Also condenser (you suspected but haven't changed) CAN give funny/intermittent symptoms, eg. start & run normally for a while, THEN play up (eg after 20 min warm-up). Can check by shorting OPEN points with a screwdriver -- with ign. on. There should be only ever be a TINY spark.

Well I've got the tank out and that is as clean as a whistle (though I found an unknown key that I could just about see wedged under a baffle in the tank, and it's not one of mine.......wierd). Blown all the pipes through including the return pipe for the fi. even though I don't even use it😕. I'll put all that back in tomorrow then I'll strip the carb. Btw I have a couple of old 34 solexes that I'm considering rebuilding but before I do is there any chemicals that I could leave them soaking in first I.e. thinners or metho?

You could gravity feed into the stationary idling car

That way you could eliminate the fuel lines?

Bit out of left field but have you checked the ignition switch wiring harness. The symptoms your describing are nearly blow by blow for me when my wiring harness collapsed. We all went looking for fuel issues as you're describing but found it was electrical.

If you read the initial post that was something I was concerned about (at least the ignition switch itself). If after all the possible fuel blockages are eliminated then it will be onto the wiring which is something I'm not looking forward to.-

I soaked my carb in kerosene overnight. Worked pretty well but after recently trying to find a bulk tin of carb cleaner I've been told a 50/50 mix of xylene and acetone is great at removing carbon deposits so should easily eat fuel tarnish too.

I used xylene and acetone when doing some fibreglass work recently so should be easy enough to obtain from your local fibreglasser. Although I would hope it doesn't eat the carb body as well!
Cheers.........Wayne

Cheers guys. The tank is all back in and the carb has been pulled apart and put back together so I'll replace the condenser and run through the wiring today,still haven't found anything obviously wrong yet though. I'll strip those other carbs anyway so they're ready to go should I need them.

Hey ancientbugger,
Hope you get this sorted. Really frustrating. What I was suggesting with my post earlier is that I don't think that just because you've replaced a couple of ignition wiring harnesses over the last 2 years or so that you should discount that possibilty again. I've just recently had a run of having to replace 3 of them in just over 9 months. The replacement units obviously aren't the same quality as the original !!!

I'm not as skilled as you guys and each time it costs me for an autoelectrician to do the work !!!

Good luck with it.

Well I replaced the condenser and fitted a rebuilt 34pict carb and so far it has run fine, still drive along waiting for something to happen though. Thanks for the input guys.

After running fine I just had to try the other carb and again no problems at all so after all that stress it looks like it was the cheapest part, the condenser! This was after extensive searching on Google 're possible problems/faults caused by dodgy condenser and this kind of cutting out just didn't come up and in my experience when they start playing up the engine coughs and darts or just won't start at all whereas this was running nicely then suddenly stopped. I do have some contactless ignition around but used points for if and when I need to check for a spark. Oh well she's happy now so once again thanks for input.

Good to hear!

Its amazing that sometimes just tackle the simple thing first.

I once had a similar issue with a car. Changed the spark plugs, no good. Changed the points, no good. Changed the leads, no good, changed the coil, no good. Changed the condenser, no good. Tried everything..... frustrating ..piece of s**t, ba*t*rd, bug#er... threw spanners at it and everything.

Cause? On the first attempt of fitting new plugs, one of the four was faulty but I never thought to question it.

Learnt from that and now am much older and wiser

Like me, for near on 30 years of driving never had a coil play up then had two in a week go up the sh*t. The condenser was pretty new but I did try googling it very early in the piece but as I said the symptoms I had never came up so I discounted it. Oh well you live and learn. I sometimes think that I should have kept a diary right from the start of VW ownership jotting down each problem as it occurred and how it was sorted as I've forgotten it all by the time it recovers.

Can you believe this has started again but this time I changed the condenser first of all but the car still cut out! Checking out the wiring now before going out to buy a new condenser. btw two different contactless ignition systems tried but neither worked? Odd

Has no-one else had this problem or is it that I have dodgy wiring? I'm double checking everything that I had previously i.e. fuel lines,pump,carburettor but nothing has presented itself as being wrong. As the car was converted to RHD some years ago I've been looking at the wiring behind the speedo and there are several wires that go nowhere but tagged things like 'No.3' or come to a plug that fits to nothing but as far as I know they have always been the same way. I just want to drive the thing without the fear of the juddering halt!

Is it just cutting out - or hesitating, mis-firing and/or backfiring? Does it come and go as you drive, or cut out entirely and require a wait?
Did you check the fuel pump Pushrod for sticking?

Electric fuel pump and yes that's running as when the car cutout I took the top of the carb off to check the fuel level and it was OK. Today though I did find that on turning it over the power to the coil turned off. Now this obviously is not the case normally as it usually starts straight away but it does suggest to me that the whole problem could be dodgy wiring.

Hi,
This is a complete new harness if you decide to go that way.
http://www.vollks.com.au/store/Vw-Bug-Buggy-Universal-Wire-Harness-W-Fuse-Box...
Thanks