No spark

[gulliver]

Hi everyone
I just cant get a spark of my twin cam. I have bought it as a non-runner and have replaced a few things, one after the other:
Dizzy cap
Coil
Leads
Condenser
Plugs
Points

With the ignition on, there's 12.5V at the coil and only 9.7V when cranking. I believe 10V is the minimum, but surely this is close enough? I have run an additional cable straight from the battery (voltage was too low when going though barrel) to get to those numbers.

It used to have a ballasted coil, now fitted with a standard 12V coil without resistor. I have disconnected the connection cable running betwen coil and starter solenoid, but it shouldn't come into play here since the engine doesn't run under its own power.

Next, I'll test the coil just in case, and check that I have 12V between the points too. The coil body is earthed to the block, and that seems ok. If there is no problem there, not sure where to look next.

Very puzzled. Any suggestion?

It is in a '71 europa, but surely Elan principles apply.

thanks
olivier

[Frank Howard]

It is in a '71 europa, but surely Elan principles apply.

Not necessarily.

Oliver,

I have a '74 Europa. My car came from the factory with a French made gear reduction starter complete with a built in solenoid right on the starter. I suspect that your car so equipped or does it have the Lucas starter with a remote starter soleniod like the Elans have?

By the way, what is a barrel?

[gulliver]

Frank,
Not sure about the starter make I'll have to check, but the solenoid is piggy backed onto it if that makes sense. A small cylinder joined to the starter. By barrel I meant the ignition key barrel, sorry.

I am thinking it is either a dodgy coil (new, but it happens), an earth issue, or my 9.7V at the coil when cranking is not enough. If the latter, I would still expect a weak spark when testing the plugs in open air as opposed to under compression.

I know what i am doing this xmas

[paddy]

Are you trying with a spark plug connected directly to the coil instead of via the distributor? Just in case your timing is wrong and the spark is happening when the rotor arm isn't lined up.

Also this way you can check by opening the points manually instead of by cranking the engine - also eliminates your concern about the low voltage when cranking (which I don't think is a problem BTW).

Paddy

[bob_rich]

Hi

The idea in one of the posts above about checking the spark is going to the correct plug is a good idea definitely worth a check. Is the timing completely way off? You seen to have a voltmeter so worth getting the static timing set up close to correct something around 8 to 10 degrees BTDC should allow it to start if all else is OK. Exact setting depends on your engine. the other thing is to check that when the contacts are closed there is current in the coil. Can you put your test meter on amps (say 10A range on test meter)? If so, with ignition off wire it in series with the lead to the coil SW or +ve terminal. If U have -ve earth car put meter -ve to coil SW (or coil +ve) and meter +ve to the lead that you removed from the coil. switch on ignition turn engine over slowly by hand (spanner on crank pulley nut) and the current should be zero when points open or around 3 to 4 A when points close. If current is always zero or always a reading then that would be wrong and should give a clue.

If a coil current of 3 to 4A is OK and interupts with points then positioning the coil eht lead centre conductor core about 5mm from earth should give a spark OK.

Hope this helps best of luck

Bob

[billwill]

Check your points gap & settings, they may not be opening.

[bcmc33]

Just two simple thoughts: do the points spark when you manually part them? and does the distributer cam rotate with the starter?

[Frank Howard]

I have disconnected the connection cable running betwen coil and starter solenoid...

Oliver,

That may be your problem. If you had a wire from the solenoid to the coil, it may be the wire that feeds 12V to the coil during cranking. I would reconnect this wire.

There is no need to remove your starter and inspect it as I am certain that it is the same one that came on my car which is entirely different than what comes standard on Elans.

[gulliver]

Thanks for the suggestions. Next I'll check the timing and do the spark check directly on the coil. I'll let you know how it goes.

The gap should be ok, I have adjusted it when changing the points. The cam does rotate with the engine, and the points open, no issue there.

[john.p.clegg]

Confession time....once upon a time ,many years ago,I had the same problem,turned out when I replaced the points/condenser I had connected the wire to the wrong side of the insulating washer ...result..no spark..?

John

[AussieJohn]

Hi JPC, you bring back memories, I did the same trick on a mini in the 60's. You could test for this with a voltmeter on the coil to dizzy wire which would show no volts at all times [ or ammeter which would show constant coil current.]

[gulliver]

Jpc and aussiejohn, you have it spot on! I had misconnected the coil -ve to the wrong side of the translucent plastic isolator on the points. So it was earthed and i couldnt read any voltage between the points when open.Not a chance in hell of working. There is now a spark on the ht lead which i am hoping to convert to a spark at the plugs after the timing is done (off by a mile at the moment). Thanks for all the suggestions

[paddy]

Well spotted that man.

[john.p.clegg]

John

[fashford]

My Elan stopped generating power the other day. On my way home, it had quit twice but started back up. Ultimately it stopped completely requiring a tow.

The first thing I did was check for spark at the plugs, finding none. Then I checked right at the coil and again found none. I replaced the coil and this has not made a difference. If it helps, I am using a Lucas "High Energy Coil" with no ballast resistor and no grounding strap.

So I started to look closer. Here is what I see:

Confirmed 11.8V to ground for the white line that powers the coil
Confirmed zero ohms from coil to ground with points closed
Confirmed no connection from coil to ground with points open
Confirmed no connection to ground through condenser with points open

For the coil, I get 2.6 ohms for the primary and 9 kohms for the secondary.

If I hook it all back up, power the coil and open the points, I should get a spark I figure, but I don't.

Can anyone tell me what I am missing?

Thanks,
Frank

By the way I am using http://mgaguru.com/mgtech/ignition/ig108.htm as a reference.