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Holden red running rough


Esky_addict

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So long story short I bunged an old 173 into a hq project I have to get it moving reregistered etc. it was running like a sewing machine then over a very short period of time it started to run rough as like it was running on 5 idled mint though, now not so much.

Tank had some stale fuel in it when i got it tipped as much out as would come out and chucked In 20litres fresh stuff to dilute it, ran most of that through just generally idling around house moving around garage etc.

Then it started missing a bit under revs and was starting to pick some shit up from bottom of tank could see it in fuel pump so i drained tank and chucked another 20l in it. Still no good spark looks good nothing's changed, blew carby out and tonight done a compression test 

165 

134

165

168

150

152

I know these aren't ideal but even the 134 is still above  ranges stated in manual. You fellas reckon this would be my problem or should it still run alright with these numbers?

Cheers

 

 

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checked filter, doesn't idle anymore so thought shit in idle circuit just opened it up and looked again. good thing is doesn't look compression related, leaning towards electrical now just had running at around 1500rpm with a miss then sort of cleared itself ran mint for couple seconds, dropped it off to idle and it idled with a slight miss for about 10 seconds then just died, very inconsistant. 

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Quite possibly the coil.

All the catalogues recommend a Coil compatible with a ballast resistor. However I have very rarely seen a red six that still has one fitted.
Measure the voltage at the input to the coil before, during and after cranking. My guess is that it has a non-ballasted ignition circuit with a constant 12V and that you have a ballast resistor type coil which has been damaged by the constant 12V supply.

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Stale fuel kills spark plugs.

Seen it, had to replace or sandblast plugs.

Pull the plugs and look at the white insulator. If they are not white but shiney grey, that's your problem. Can't even scrape it off with a knife.  The coating is all the additives they put in fuel not burning off due to not enough heat. 

Do a stationary radiator load test to clear the plugs.

Or put new ones in it.

Also remove the fuel tank and run a steam cleaner through it, for at least 5 minutes, enough to get the tank hot. This will realease the additives that have soaked into the metal.

Done it before, works.

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you beauty I tried everything even had plugs out for a look and a clean as they were a bit fouled, after reading that I cleaned them with wire brush and she's purring again now bloody rapt. 

stale fuel must of sat on top and only gave issues after using up the fresh stuff. It was fine then It was away for a few days while getting rooflining done and got it back running like poo basically.

Had me guessing i wouldn't think baked up plugs would cause a backfire like that it was backfiring at both ends under load. and would run then just drop and die randomly,

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  • 1 month later...

Bump. These coils get me every time i need a new one. 

Holden still has factory resistor wire, went into BNT to get a new coil there options were C-80 or C-80r, I grabbed a C-80 thinking oh well if its not the right one ill just get a resistor to chuck in there but....

Does the R mean they are internally resisted or they require an external resistor?

I'm thinking now I'm running a 12v coil with reduced voltage hopefully causing my miss under load/acceleration 

Edit. lol just reread thread so yeah basically what threeontree said but opposite.

 

 

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Measure the resistance across the primary circuit of the old coil.

Coils that don't require a ballast (C-80/GT40 etc) have 3 ohms resistance and ones that are externally ballasted (C-80R/GT40R) have 1.5 ohms. 

Note - it may be K-ohms. I can't remember it's been fucking years since I've needed to measure one and I don't have my multi-meter in front of me to see what setting I normally put it to when testing.

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