International Vintage Volkswagen Forums

Hi , just wondering if anyone has any ideas as im starting to run out. My oval has an issue when its hot but only sometimes. It will start when cold no problems, i can go for a drive for say 5-10 miles then pull over to fill up with fuel. After filling up the beast it just wont have it, it turns over quite lazy and refuses to fire.I`ve checked a plug just after churning it over for a while and it wasnt wet.
I have done the usual, the battery is good,6.45 volts , new points,plugs,condensor,cap,etc. Valves are checked and right, good earth and charging at 7 something volts.I`ve just put a meter on the coil when turing over the engine on the starter and the volts are dropping to 5v. I`m running a judson supercharger with matching coil, just rebuilt the charger with new rotor and vanes/bearings etc.
Like i said the car runs perfect, doesnt run hot and pulls really well, its not over timed. The only way sometimes to get it to go is to push start it which always works. The weird thing is, once ive pushed started it, i can turn it off then the bloody thing will start on the key instantly! Its really driving me mad now. I`ve got a second starter which im going to chop and change parts with the one thats on the car now. I was also thinking of buying one of those optima batteries?!
Any suggestions?

Sounds like you have a voltage drop somewhere due to a bad connection. If the ignition system is also suffering from this drop (while the starter is active) then you will have significantly less spark voltage. Both of which will give you bad starting.

While the fault is present, give it a good cranking on the key then check the battery leads for any heat - this is a sign of a bad connection. Do the same at the starter and both ends of the gearbox earthing strap. In any event, it won't hurt to give all of those connections a strip and a clean but look for heat first just so you know where you have a particular problem area.

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Why would it start fine after i`ve bump started it then? If it was voltage drop it would be difficult to start all the time?
I will check all the connections and mainly the ignition switch, maybe that has something to do with it.

This is often something that happens when the old worn starter gets hot...

Easy to start when cold, and easy to bump start when warm, but starter turns slow when hot... change the starter and it will probably be fine.

I've had this with "warm" worn starters a few times.

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yep poss starter or worn bellhousing bush that starter goes into

Hello. I have exactly the same problem with a '65 bus at the moment, always at busy petrol stations! As already said above, there is a high chance it is due to a worn starter getting hot from the heat of the engine which cause the solenoid to stick (and makes it sound like your battery is flat). A new starter should hopefully cure it.

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Hmmm, perhaps a new one is the answer. Replacement ones dont seem cheap though! Where is best to get one, VW Heritage and KK is obvious, any other places in the UK? Does 5v at the coil when the starter is engaged sound right. I will check the ignition switch too i think.
Cheers for the replies.

I had same problem with mine, changed starter and all was well. Just make sure you change the starter bush and give the connections a damn good clean at the same time. The voltage would drop if the starter motor was pulling excessive current.

Hi
you may have a few problems adding up to poor starting, before you change the starter take a look at the support bush in the bell housing, this can be changed with the engine in but is a pain, if its worn the starter will turn slow and draw too many amps also check the earth strap from the gearbox to the body and clean up its connections and also the battery earth strap too, a handy dodge is to wire in a relay to take a supply directly to the coil when starting and to take the load off the ignition switch too, this takes care of "coil robbing" this is basically all the battery power going to the starter when cranking and the poor old coil not getting enough juice for a decent spark, I have a number for a company who could supply a 6V relay,though Karmann Konnection may have one,drop me a line if you need it, Bill.

Hi, i did speak to Jules at KK and i mentioned the stater relay which is the cheaper option which i might give a try. The earth connections are good (new ones), i replaced the gearbox one when i changed the box a few years ago. As for the starter bush , well thats seems like a good idea anyway, i`ve got access to a two post lift for an easy life!

Job done, fitted a new starter and bush .It sounds different to say the least! It starts no trouble so far but will take it to the aircooled breakfast meet in Caernarfon on Sunday for a proper test.
Cheers .