Why won't my car hold a charge?

[mk2mark]

Right guys, periodically for a few seconds at a time my car runs out of power altogether, as if it's not getting spark at all. The rest of the time it runs perfect. Sometimes this happens bad enough for me to have to pull over to the side of the road. When this happens I usually have 3 or 4 twists of the key to get it started again before the battery runs flat Brought it to an electrics place, the battery is confirmed ok, and the alternator puts out a healthy 13.7v - although this is when the car runs well.

[russ-vdub]

could be the connection on the negative on the coil maybe..mine did that and it was because it was arcin from the + to -..thats all i can think of expect for your dizzy cap and rotor arm might be a bit dodgy

[VeeDubGTI16v]

maybe clean or replace the brushes in the alternator?

[E405]

^what they said^ and check earth strap to gearbox too!

[clipperjay]

You need to get a multi meter then test the volts under load with all electrics on see if it stresses the alternator?
You might just have a bad earth I would dremwl or snad paper any postive nad negative oxidised connectors and spades just to get a better earth. The other thing is to replace any real rusty earth straps its worth doing just to keep arcing and leaks down.
Your volatge regulator might just be going under load so when you test at idle its fine its when its under stress then it starts to be irregular in voltage output.
 
J
 

[DarnPB]

I agree with the earthing suggestions. Remove your earth straps from engine to gearbox to chassis to battery, and clean up the faying surfaces to bare metal. Refit and try again. If it cures the problem, then go back and cover the earth point in silicone sealant to stop the rain, salt etc from getting in.

[mk2mark]

Cool, will do! Cheers guys