Hey,

I'm at a loss with this one!

I've had this 69 Beetle for about 3 months now. She's had starting issues when hot, which can be a problem if I just stop to refuel.

Earlier the engine had issues with cutting out. She would fart and sneeze, then completely die in the arse. Generally it wouldn't start until I'd given her a chance to rest, then she would start again as if nothing was wrong.

I suspected fuel problems in the carby, so I brought forward my planned purchase of a new 34PICT unit and installed it. The issues continued but things were slightly better, so I thought maybe a stronger spark would help, so I installed an Accufire module into the distributor.

She started and ran fine, but still the same issues with the engine missing, cutting out then eventually stalling.

Later it was suggested that it could well be a fuel delivery problem. So I went and got a new fuel pump and found that the cutting out has virtually stopped (after it has warmed up of course). Today though, she had a bit of a miss and I turned the engine off so I could see what the fuel was doing (I'll probably draw heat for this, but I've put the inline filter between the pump and the carby for the time being so I can see what's happening with fuel delivery). The filter looked almost empty, but not completely, so I went to start up again and go.

You know what comes next...

She turned over fine but would just not start. I initially tried to start it without touching the accelerator, then tried while holding it down, then tried after pumping the accelerator...nothing.

I checked spark, it was there. I looked down the carby throat and could see the stream of fuel as I pumped the carby, so fuel was there. I disconnected the fuel line and was met with a squirt of fuel under pressure, so the pump was chugging nicely.

So, as I've done in the past, I let her sit there and have a good hard think about what use she is as a car that won't start. Thirty minutes later I give the accelerator a pump, turn the key and she roars into life.

Didn't miss a beat all the way home. I parked in my garage, turned the engine off waited a minute then tried to start up again...nothing.

So why?

Any thoughts?

This is interesting although must be frustrating for you.

The way I see it is that you need 4 things to make an engine run: air, fuel, spark and timing. Sorry if I'm preaching to a priest here.

- Air is clearly not the problem...it runs fine usually
- Fuel delivery seems to have been sorted, although it sounds similar to a vapour lock condition. Should there be an insulating spacer used between carb and manifold for example?
- Spark you say is present. How did you test it and did you test all 4 plugs? Most importantly did you verify spark when cranking the starter?
- Timing must be close enough as it runs well

If this doesn't help I'm sure you'll get an answer pretty soon!

EDIT: thought about this a bit more...it could also likely be the ignition coil is stuffed and breaking down under excessive heat, or there is a wiring fault in the ignition circuit worsened by heat. There is a fair bit of heat soak through all the parts in the engine bay when you switch off a hot engine

just out of curiosity... since u didn't mention it
have you done the tappet recently?

I had issues with my new engine cutting out alltogether, whilst on the freeway. Similar issues with starting first go and not starting at all randomly. Turned out to be a faulty ignition switch. Replaced with a new one, and haven't had an issues since.

Nick

Had the same issue with my type 4 motor. Got a full service a tune and tappet adjustment and has run fine since and started when it's roasting.

Hey guys,

Thanks for your responses. It's good to get a few different points of view.

Considering the 4 points type3lover raised - air, fuel, spark and timing, I think that I'm on track. I did wonder about the possibility of the coil struggling in the heat, but haven't yet eliminated that as a possibility. The coil that she has is a blue Mexican or Brazilian beasty, and I have heard that they can be a bit suspect when it comes to quality.

Wiring fault in the ignition circuit? Hmm, maybe - I'll look into that and report back later...

I'm not sure about vapour lock, but am interested in getting a better understanding of it. I'll Google it, but I don't think it's anything like that.

As I was roadside, I checked the spark in rather agricultural fashion. I basically put a screwdriver in the no. 1 plug lead hole in the distributor cap and held the end of the lead close to it while the engine was turned over. Spark was present there so I wasn't too concerned about the other 3.

Tappets? No, I haven't done a tappet adjustment recently but I think I know what you're getting at Shep. I guess that there is a chance that could be behind the sneezing through the carby, etc, when the engine was hot.

Food for thought! I know it's GOT to be something relatively small, and I will definitely be a happy man when I've finally nailed it.

There's a part of me that believes she is just acting up in the knowledge that I'll keep buying new stuff for her!

when it you cant restart it undo the petrol cap an d see if it gives a big suction sound from the tank , as your breather from the tank might be blocked.

i had the same problem replaced the coil and all is good.
the coil was getting hot.

yea my thoughts coil or ignition so get or make a jumper wire so you can jump from batterty to positive on coil also fel the coil after a bit of a drive if it's to hot to touch you mite have found the culprit the wire will bypass the ignition so if all well faulty ignition
good luck

Hey again,

I thought about the fuel tank breather and listened for a hiss when I cracked it, but there wasn't one. Good thought though.

A jumper wire between my alternator (I replaced my generator) and the coil is a top idea. I'll slip one in the glovebox before I take her out next. Thanks Greedy.

As for the coil...well that's next on my list of replacement parts. Then I might look at tappet clearances.

i also had a dodge coil, swaped it, never had any issues.

So a Bosch GT40 would do the trick?

i had a new one go on me after 4 hours and it took bloody forever to work it out because it was new

my 64 beetle used to have similar symptoms caaused by vapour lock. Does the engine run hot? is it wearing all the cooling tinware? I found on the odd occasiion that a SMALL tap on the inlet of the carby was enuf to dislodge the bubble in the inlet pipe. hope that helps.
Cheers
Chippy

PM sent

I had a /ery similar issue. my coil wire was earthing.

old wiring breaks down. I would definatly suggust running a wire from power to the coil and trying again. Bypassing the ignition switch and all the wiring between it and the coil.

In fact if you dont seem to ha/e /apour lock i would be surprised if it is not the coil or Condensor or power wiring for either.

Nicko

I had a very similar issue with my '82 Camper. After replacing almost everything including coil, starter and solenoid it turned out to be a loose spade connector in the plug in the back of the ignition switch. Since pushing the connector back in I have had no further starting issues. My guess was that the voltage at the coil was just a little low when hot and thus starting became an issue.

Ian

same issue with my old square. was a faulty coil.

give this atry after dark start the engine or get someone to and see if there is any pretty lights in the engine bay you will see the flashes

Hey all,

A quick update for those that were interested. I've been running a replacement coil now for about six weeks and haven't had the problem since. It seems that the old coil must've been failing in the heat.

I didn't want to post too soon because I kinda felt that if I did, the temperamental little bugger would've made a liar out of me!

All good!

Hey that's good news, I know what ya mean about not posting earlier, I believe in Herbie too!