Chimeara won't start.
Chimeara won't start.
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Discussion

tvrash

Original Poster:

84 posts

112 months

Thursday 12th October 2017
quotequote all
I guess it had to finally happen, coming back from Castle Combe our Chimeara just cut out, no warning whatsoever. All electrics work, engine turns over strongly but no spark, not even trying to fire.
There was possibly some warning signs, the week before when accelerating hard the car would stutter for a few seconds then clear. On the way up to Castle Combe the stutter was a little worse but again cleared and the car ran beautifully.
I have swapped coil, ignition module and rotor arm.
Any ideas would be appreciated.
Something else, the pump doesn't prime every time I try and start, I can hear the relay in the footwell but no priming. I've checked the wires to the pump, they are fine.

sparkythecat

8,060 posts

277 months

Thursday 12th October 2017
quotequote all
You've taken a plug out and there's definitely no spark at the plugs?
Can you get a spark off the coil king lead ?

If the answer is yes, it's a distributor problem. Check cap and rotor arm .
If the answer is no, replace king lead and try again.

Edited by sparkythecat on Thursday 12th October 17:41

tvrash

Original Poster:

84 posts

112 months

Thursday 12th October 2017
quotequote all
Tried a plug and the king lead, nothing.

sparkythecat

8,060 posts

277 months

Thursday 12th October 2017
quotequote all
You've replaced the coil, but have you metered the low voltage supply to the coil ?

tvrash

Original Poster:

84 posts

112 months

Thursday 12th October 2017
quotequote all
No I haven't, please explain 😁

tvrash

Original Poster:

84 posts

112 months

Thursday 12th October 2017
quotequote all
sparkythecat said:
You've taken a plug out and there's definitely no spark at the plugs?
Can you get a spark off the coil king lead ?

If the answer is yes, it's a distributor problem. Check cap and rotor arm .
If the answer is no, replace king lead and try again.

Edited by sparkythecat on Thursday 12th October 17:41
The king lead is the only part I haven't replaced. Would they fail instantly ?

sparkythecat

8,060 posts

277 months

Thursday 12th October 2017
quotequote all
Your ignition coil takes a 12v DC supply and converts to a very high voltage.
If you are not getting a spark at the king lead and the king lead and coil are sound, You need to check that there is 12v reaching the coil.

tvrash

Original Poster:

84 posts

112 months

Thursday 12th October 2017
quotequote all
sparkythecat said:
Your ignition coil takes a 12v DC supply and converts to a very high voltage.
If you are not getting a spark at the king lead and the king lead and coil are sound, You need to check that there is 12v reaching the coil.
What is the best way to test that ?

tvrash

Original Poster:

84 posts

112 months

Thursday 12th October 2017
quotequote all
I should add that I'm good with mechanical but electrics just flummox me lol

sparkythecat

8,060 posts

277 months

Thursday 12th October 2017
quotequote all
Take the two spade terminals off the coil and connect them to a test meter or a 12v bulb. See whether the bulb lights or what voltage is shown on the meter when you turn the key.

If you get no voltage, or the bulb doesn't light when you turn the key, , you've got a problem elsewhere in the circuit.
If the bulb does light or you get 12v or more on the meter. Its a coil or king lead problem.


tvrash

Original Poster:

84 posts

112 months

Thursday 12th October 2017
quotequote all
Thank you, I will try that in the morning. Hopefully it's a king lead because it's a new coil. Can they just fail instantly like that ?

N7GTX

8,260 posts

165 months

Thursday 12th October 2017
quotequote all
To test it, take it off. Take any one of the plug leads off and fit the distributor end of the lead into the coil. If you get a spark now then the king lead has failed. If you still get no spark then possibly coil or amplifier problem.

tvrash

Original Poster:

84 posts

112 months

Friday 13th October 2017
quotequote all
I'm going to try that when the wife gets home, at least it will cross one thing off the list.

Sardonicus

19,313 posts

243 months

Friday 13th October 2017
quotequote all
You wont see 12v at the coil until you crank the motor the coil is only ground whist cranking (the module creates the ground pulse) unlike a points set-up if the points are closed with just the ignition on no cranking wink just saying

tvrash

Original Poster:

84 posts

112 months

Friday 13th October 2017
quotequote all
Thanks. So crank it and check for voltage ?

tvrash

Original Poster:

84 posts

112 months

Friday 13th October 2017
quotequote all
OK, update. I have tried to get a spark by using one of the plug leads directly in the coil, no spark. Of course it is possible that the new coil and/or ignition module are defective but I have to assume they aren't so I seem to have no power to the coil. Any thoughts on what to look for next ?

Loubaruch

1,403 posts

220 months

Friday 13th October 2017
quotequote all
The ignition circuit is immobilised, can easily be bypassed to rule that out.

tvrash

Original Poster:

84 posts

112 months

Friday 13th October 2017
quotequote all
Loubaruch said:
The ignition circuit is immobilised, can easily be bypassed to rule that out.
OK, when you say easily, you mean under the dash at the immobiliser ?

blitzracing

6,418 posts

242 months

Friday 13th October 2017
quotequote all
Two connections on the coil- positive - this should have around 12 volts on it with the ignition on, and without the engine turning. If you dont have a voltage its likely the immobiliser. If the engine is not turning, you should also see 12 volts on the negative connection as well, as the ignition amp is "open circuit" at this point. If you have 12 volts on both terminals, unplug the ignition amp, and take a wire from the negative terminal dab it to ground- it should make the coil produce a crack as it sparks. If this works then the amp or its wiring is faulty. It has been known for the wires from the trigger head to break so the amp does not get a trigger signal.

My 10ps worth on it:

http://www.g33.co.uk/pages/technical_ignition_syst...

tvrash

Original Poster:

84 posts

112 months

Friday 13th October 2017
quotequote all
blitzracing said:
Two connections on the coil- positive - this should have around 12 volts on it with the ignition on, and without the engine turning. If you dont have a voltage its likely the immobiliser. If the engine is not turning, you should also see 12 volts on the negative connection as well, as the ignition amp is "open circuit" at this point. If you have 12 volts on both terminals, unplug the ignition amp, and take a wire from the negative terminal dab it to ground- it should make the coil produce a crack as it sparks. If this works then the amp or its wiring is faulty. It has been known for the wires from the trigger head to break so the amp does not get a trigger signal.

My 10ps worth on it:

http://www.g33.co.uk/pages/technical_ignition_syst...
OK, I'm getting no voltage to the coil, just to be safe I tried ignition off, ignition on and cranking. Nothing at all. I'm thinking immobiliser, in which case how do I bypass that circuit ? I'm happy not to have an immobiliser as I'm planning a new one over the winter anyway.