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Author: Subject: Where's My Spark?
GeoffH

posted on 29/4/14 at 05:15 PM Reply With Quote
Where's My Spark?

I posted on this issue some time back and annoyingly, it's still not fixed.

I've been trying to start my 1600 X/Flow since it came out after the winter in February. Before that it ran fine, pretty much. I did occasionally get misfires when starting, which cleared after a few minutes.

I have a Lumenition optical system and get a spark from the HT lead to earth when interrupting the light beam on the switch - as it's supposed to. However, no spark at the plugs. Changed the rotor and cap, the contacts in the old cap may have been slightly worn. Checked the ignition switch was supplying the coil while starting, all ok. The coil does get warm after my tests but works fine otherwise wouldn't get the spark from the HT lead. Checked the resistances on the coil, seem ok for the Lucas Sport coil - slightly higher than the regular coil.

This is pretty much a total failure rather than a slowly breaking down kinda problem, it was fine before the winter save for the sometimes mis-firing on starting, now, nothing.

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steve m

posted on 29/4/14 at 05:30 PM Reply With Quote
on a xflow, assuming the engine has not been taken apart it can only be

leads wrong way round
timing out or moved
wiring to the coil not connected, try a jump lead from the + on the battery to the + on the coil wil do the same as ignition on

coil shagged
lumention shagged, i removed mine as a bit duff, might have a couple of old ones knocking about

and that is it!!

steve





Thats was probably spelt wrong, or had some grammer, that the "grammer police have to have a moan at




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rusty nuts

posted on 29/4/14 at 05:50 PM Reply With Quote
I recently had problems with intermittant starting on my GTM which had a Lumenition system fitted and like you had a spark when interrupting the optical sensor but it still wouldn't start even with new leads,coil, cap ,rotor and plugs. In desperation I brought and fitted a new Lumenition kit, still wouldn't start so I ripped the electronic ignition out and fitted a set of points and condenser. It fired up straight away and hasn't missed a beat since. I will not be using Lumenition again
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jacko

posted on 29/4/14 at 06:01 PM Reply With Quote
http://www.youtube.com/watch?v=yLoZ0pxLWGE

Found them
sorry no help to you
Jacko

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GeoffH

posted on 29/4/14 at 06:20 PM Reply With Quote
I should have said I had the plug out of the block, with the HT lead attached when I tested it. No spark. But sparking from the HT lead that goes to the distributor when held near earth.

Strange but interesting Rusty Nuts, that you had the same problem and had a spark from the HT lead when interrupting the optical switch, but no starting. How can that be?

Geoff H

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jacko

posted on 29/4/14 at 06:32 PM Reply With Quote
Do you mean the ht that goes from the coil to the dizzy ?
if so it must be to do with the dizzy cap / rotor is the pick up in the cap ok

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rusty nuts

posted on 29/4/14 at 06:32 PM Reply With Quote
Don't know why but it was the same with a brand new Lumenition fitted , It might be worth trying a set of points and condenser? I had checked all wiring etc with no luck and the previous owner had problems as well but since junking the electronic ignition it starts on the button every time
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gremlin1234

posted on 29/4/14 at 07:55 PM Reply With Quote
the problem is quite simple,
too much spark, destroys rotor arms and caps very quickly.

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avagolen

posted on 29/4/14 at 08:16 PM Reply With Quote
Where abouts are you?

Maybe some kind person with experience can drop by and lend a hand.







The Answer for everything, but never the last word....

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GeoffH

posted on 30/4/14 at 08:44 AM Reply With Quote
I replaced the cap and rotor last week. That was my thought too, the power gets as far as the end of the HT lead but not the plugs.

Given I get a spark at the HT lead when operating the optical switch, could it be that when the engine is turning over, it's too fast to generate a lot of sparks for some reason? Coil or Lumenition power module? Although this test is said by Lumenition, to confirm the whole system is working ok.

I'm based in Hampstead, London if anyone is nearby.

GeoffH

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DW100

posted on 30/4/14 at 11:00 AM Reply With Quote
Do you get a spark on the main HT lead whilst cranking? or only when manually breaking the beam?
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jacko

posted on 30/4/14 at 03:42 PM Reply With Quote
My sound daft but has the engine got a good earth to the chassis / battery and are you putting the spark plug on the engine when cranking the starter
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GeoffH

posted on 30/4/14 at 07:01 PM Reply With Quote
Yes Jacko, good earth and spark plug touching engine while cranking. The engine had a lead straight to the battery.

DW100, I get a spark from the HT lead when breaking the beam. While cranking I don't know, I'm too far away at the ignition switch to see. I've tried that but in daylight I can't see if there's a spark or not...or indeed hear if it's sparking.

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avagolen

posted on 30/4/14 at 08:28 PM Reply With Quote
Sorry - I cannot get to Hampstead, but have you tried it in the dark to see if the HT leads are tracking.





The Answer for everything, but never the last word....

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DW100

posted on 1/5/14 at 02:47 PM Reply With Quote
Ok to get to the bottom of things like this you have to go at it in a logical manner and not just do random things.

You have worked out that you have no spark at the plugs.

You have a spark whilst breaking the beam, so the next step is to check with the car cranking, if necessary by getting an assistant to press the starter button. Follow the path of the spark, testing till it disappears.

If you have no spark whilst cranking then check the the chopper in the distributor is actually rotating.

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GeoffH

posted on 1/5/14 at 02:56 PM Reply With Quote
DW100, ok I'll try that at the weekend. I've checked the chopper is rotating, I turned the engine over with the distributer cap off.

GeoffH

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GeoffH

posted on 13/5/14 at 11:34 AM Reply With Quote
So I checked everything last night when it was dark, and I have sparking at the distributor end of the HT lead and at a plug. May have been last time I checked it was too bright to see!

Anyways, engine still won't start. I can smell petrol on the plugs so there's petrol in the cylinders. If it's a mixture problem, I have a single Dellorto 45 side draught. Ran fine before the winter with the occasional misfire on starting, which cleared when it was a bit warmed up. Also, one time it stopped completely and I think that was because of an air lock in the fuel line somewhere as no fuel in the filter, but when I loosened the fuel to carb, connector, all was fine again.

GeoffH

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DW100

posted on 13/5/14 at 12:01 PM Reply With Quote
Ok well keeping to the basics. For it to fire you need Spark, fuel and compression.

I you have all these then you need to start looking at spark timing (this includes correct firing order)

and then fuel mixture ( is the carb flooding? Spark plugs that are soaked in fuel won't fire correctly)

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GeoffH

posted on 13/5/14 at 12:09 PM Reply With Quote
Hi David

I'm assuming the firing order and timing are ok, it ran before the winter, but I'll check the firing order.

How do I know if the carb is flooding and if so, what do I do about it?!

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DW100

posted on 13/5/14 at 12:30 PM Reply With Quote
Make sure you have the firing order correct, then try a fresh set of plugs.

It is very easy for an electric fuel pump to provide more pressure the the needle valve can close against. If you have an electric pump then check you have a pressure regulator set to about 2psi.

Another thought is that you have stale fuel that refuses to burn.

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GeoffH

posted on 13/5/14 at 12:41 PM Reply With Quote
Thanks DW

I'm using the X/Flow mechanical pump with a Malpassi pressure regulator but there's no way of telling what the pressure actually is, or of setting it to a specific pressure.

Is there really such a thing as stale fuel??!!

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owelly

posted on 13/5/14 at 03:40 PM Reply With Quote
Unleaded fuel does 'go stale' so just to use a process of elimination, squirt a puff of Easystart down the carbotooter. If it fires, you have fuelling issues. If it doesn't run, you're back to chasing your missing sparks!
For me, the logical route would be:
Puff of Easystart to see if we're missing fuel or sparks.
If looking for sparks, stuff a spark plug in the end of the coil lead and check for a nice big fat spark.
If there's no spark, or it's feeble, go back to the LT wiring. With points, it's easy to see what's what but with electronic, optronic, etc, it's not so easy.
If there's a fat spark at the end of the coil lead, then put the coil lead back onto the dizzy cap and check the rotor arm is OK and not burnt.
Check the brush in the middle of the cap/rotor arm.
Then try a full set of plugs in the ends of the leads and lay them where they are grounded to earth. Check for sparks at each plug. They should be big enough to see in daylight.
If you're losing the spark between the coil lead and plug, leads, you need to be going back the the dizzy cap and rotor arm. Check again for tracking and/or cracks. Clean the inside of the cap thoroughly. Tracking can look like a hairline thick pencil line.
Check the rotor arms peg is in place and that it's sat in the groove correctly.
Make a checklist and get back to us with results!
Good luck.

ETA: the Lumention on my old A-series was very voltage sensitive! The cranking voltage dropped to 10v and it refused to start. Changing the coil for a coil and ballast resistor helped for a while but ultimately, a new battery cured it!

[Edited on 13/5/14 by owelly]





http://www.ppcmag.co.uk

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GeoffH

posted on 13/5/14 at 03:55 PM Reply With Quote
Hi Owelly

Thanks for this,

As the thread has become rather long, to get you up to speed (!) I now have sparks at the distributor and of the HT lead and from one plug held to earth, while cranking. Haven't checked the others but likely to be ok.

The distributor cap and rotor arm are new. Lumenition told me the drop-out voltage for their system is about 6v but not really relevant now.

How do I check for carburettor flooding?

Maybe try the Easy Start at the weekend.

GeoffH

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avagolen

posted on 30/5/14 at 08:13 PM Reply With Quote
Hi Geoff,

Have you fixed it yet?





The Answer for everything, but never the last word....

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GeoffH

posted on 31/5/14 at 12:11 PM Reply With Quote
Amazingly YES!

Thanks for asking.

Owelly and a couple of others in the thread suggested it could be bad fuel, gone off over the months I hadn't used it.

I have to admit I was very sceptical about this, thinking it was an old wives tale. But I did a bit of research and apparantly fuel does go off, losing it's volatility, if left over a few months which mine was over the winter.

So I sucked all the fuel out of the carburettor with a syringe from the local chemist. Replaced it with brand new fuel and Boom!!
It started.

It spluttered for a while, I guess from the old fuel still left in the pipes but when the new fuel in the tank got though, it ran fine.

How about that!

So thanks everyone, what a revelation!

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