Dead Chimaera - no spark at plugs.

[GrahamBell2026]

The other day my Chimaera suddenly died on me. Running great one moment, next moment not running at all.

Checks confirmed good spark from king lead but no spark at plugs. No obvious faults within distributor cap, the air gap in the distributor pick up is correct, rotor arm is expensive Distributor Doctor item so shouldn't be tracking, and it's whizzing around quite happily.

All fuses and ignition feeds relay OK and with nice clean contacts. Coil has 1.1 ohm on primary and 52500 ohm on secondary, so coil looks OK.

Was getting nominal 12V at the coil +ve with ignition on, but also getting 12V between battery +ve and coil -ve with ignition off, which according to Haynes manual indicates fault in amplifier unit. So got new Powerspark module and car still won't start and is still showing 12V between battery +ve and coil -ve with ignition off. It's still also showing nominal 12V at coil +ve and still has good spark from king lead but nothing at plugs.

Could faulty distributor pick up cause this? (Still shows 12V at coil -ve with pick up disconnected.) Otherwise I'm out of ideas, so any suggestions welcomed.

And if I can't fix it, can anyone recommend a good TVR savvy garage in central Warwickshire who could sort it out?

[foccer]

Just becasue the rotor is expensive, doesnt mean its the right one. Is it making contact with the cap contacts? Try a new cap and rotor.

[GreenV8S]

If you have a spark at the king lead, doesn't that suggest that everything up to the king lead is working?

I suppose I could contrive a bizarre electronic failure which caused a spark at the wrong time wrt rotor arm position, but there's nothing to make me think that's happening here.

Is the vac advance cannister still plumbed in and holding vacuum?

Can you gently twist the rotor arm to increase the advance and feel it spring back to the rest position again?

[silentbrown]

Odd. No spark at all at the plugs? None of them?

Sure you're testing for a spark at the plugs correctly? Needs to have a good ground for the plug body.

Engine earth strap failed??

[Belle427]

Do you have 12 volts at the coil positive terminal when cranking?
Worth checking this if your just doing it ignition on.
Powerspark stuff is junk so i would get an original old stock module, not that im saying its that.
https://www.ebay.co.uk/itm/133318230946?_skw=lucas...

[Zeb74]

Do you still have the plug extenders?

[GrahamBell2026]

Well don't know what happened to my response yesterday. Anyway, thanks again for all the replies chaps.

Decided to set the engine to TDC to check that all the timing was still aligned - which it was. While I had the distributor cap off I thought I might as well stick the old rotor arm in. Took number 2 plug out and laid it on top of plenum to check for spark I wasn't expecting to see - and it bloody well fired up!

Have just run it up to temperature, so once it's cooled down I'll try it with the Distributor Doctor rotor arm back in and see how that goes.

[GrahamBell2026]

Well just tried it again with the Distributor Doctor rotor arm and it wouldn't start. Put the old Lucas arm back in and it fired up straight away. So the Distributor Doctor rotor arm is clearly the culprit, though I can't work out why as I can't see anything wrong with it. Still, problem sorted which is the main thing.

[Belle427]

Unusual, his stuff was said to be high quality but probably another one to put on the proceed with caution list!

[GrahamBell2026]

Yes, that's why I got one, following tales of cheap Chinese aftermarket arms with too much carbon black tracking and shorting out.

[Belle427]

If you have the original lucas one its probably worth sticking with.

[indigochim]

I had a DD rotor arm let me down a few 100 meters from the end of the Peeks to the Beach a couple of years ago. I was very disappointed as you think you're buying parts to protect you from failure. I now cary spares of many of the ignition components just in case.

[Byker28i]

Yup, been out with others and had failures of rotor arms from known suppliers, but also dizzy caps as well, with the central carbon brush breaking in half/off, so no contact made

[GrahamBell2026]

Doesn't say much for the quality of modern parts does it? This is the second part that's let me down after I decided that the old ignition parts were due a replacement (the first being the Viper coil). So now running with old black Bosch coil and old Lucas rotor arm. Original distributor cap and plug leads on standby....

[Belle427]

I would report the failure to the distributor doctor though, they may have it back for testing.

[Byker28i]

I've seen a rotor arm on a griff not be insulated but conduct the high voltage, effectively earthing it, hence a really poor, barely existent spark.
That was a couple of years back., and was sorted with putting the old rotor arm back on after a clean

[GrahamBell2026]

I suppose I could have contacted Distributor Doctor about returning it for testing - except I've now thrown it out. But not sure they would have been interested anyway as it was several years old when it suddenly failed.

[Belle427]

Not too bad then depending on mileage.