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Section : Ignition and Distributers
Posted By : Andrew Done, 11-May-2004, 04:09pm
Grrrr, on one of the few occasions that I have started the engine with the bonnet up on my Mk 3 Spit, I see smoke and closely followed by that disturbing
burning smell. (Would say burning rubber, but didn't want encourage the inevitable smutty comments)
It seems that the wire from the battery (+ve) to the thingy (yes I have not looked in the manual to see what it is yet) that sits next to the coil, seems
to get a tad warm when turning the engine over! Is this problem a syptom of lack of ballast resistor wire? Or high resistance connection? Wrong coil? No
problems once started, due to reduction in current drawn from battery I presume?
If it is lack of ballast resistor, is it best to fit the resistor wire or buy a new coil (12v)? (Club flame thrower thingy for example - name seems to
disturb me a little, get a bit nervous about the smoke to be honest!)
Suggestions please?!? And thanks to those who have helped me out with Exhaust fitting and UJ problems.
Andy
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Posted By : Mark Astley, 11-May-2004,
05:49pm
Hi,
The thingy would be the starter solenoid,
hot cable would suggest to me either too much current being drawn by the starter motor or the cable degrading and developing its own resistance to the
current flow. Copper cores go brittle with age and some may be fracturing and interrupting the flow, the ampage through the remainder makes it get
hotter as a result
The ballast resistor would only be in circuit after the engine is started as it is bypassed when the starter is being operated to give a full 12v to
the coil rather than the 6v normally to give a bigger fatter spark. So unlikely to be a cause, likewise the coil as it will be using the same current
at starting as when running and it wouldn't be enough to get the main positive feed to get hot.
Check with a multimeter what voltage you have at the battery terminal and what you get at the other end of the main cable to see if there is a problem
with the cable, wouldn't expect any more than 0.1/0.2 volts difference if any at all.
You might get a different result with the engine running (I've never tried this) due to the alternator effect and it may disguise a cable problem as I
think the alternator feed connects onto the starter solenoid.
hope that helps
mark
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Posted By : Doug Paterson, 11-May-2004,
06:22pm
Even if the cable has developed enough resistance to result in it heating up so much, I don't think you'll get a different voltage reading at each
end of the cable.
I would just change the cable and check it solves the problem. Isn't going to be expensive after all.