DMC Ignition Question

D

dave48

Junior member
Location
Missouri USA
I recently installed a new DMC ignition in my 78 Jarama. When power is applied to the ignition system all (3) sparkplugs fire. Is that normal?
Because of this, gas vapors in the intake will ignite. This seems to be random cylinders. I think it?s whatever intake valve is open. Has anybody seen this?
 
Dave

Sounds like you might have it in test mode.
Is it a DMC2?
What setting are you on?

On my 120 version of the DMC2,  I think it's curve 0 that is a test setting that allows you to check for sparks across all three cylinders.

T.
 
just to clear up one point here
you are saying they all just fire once at the point that you turn on the ignition, is that correct ?

they are not in a continual firing mode are they ?

 
dave48 said:
I recently installed a new DMC ignition in my 78 Jarama. When power is applied to the ignition system all (3) sparkplugs fire. Is that normal?
Because of this, gas vapors in the intake will ignite. This seems to be random cylinders. I think it?s whatever intake valve is open. Has anybody seen this?
Click to expand...

Yes.

Yes.

My RGS almost starts up when I turn the key... :D

piet
 
James,

One of these days it's going to surprise me and roar into life without needing to press the button... just hope it isn't in 1st gear when it does! :D

These things have a life of their own. ::)

piet
 
Oh, if it's just a single spark when you flick the kill switch?

That's not just a Witt thing, I think all battery fed electronic ignitions do that.

Mine will only actually pop or fire though if I've been messing with the throttle first. On the standard water pistol dellorto carbs, there's more than just vapour in there then!!

Certainly makes you jump when it does bang though, probably excentuated by the dull echo from the Jota pipes...

Peace Out

T.

 
Lex.3CL said:
The de witt I had installed started doing exactly that not long before it died. Would throw a spark when ignition first turned on, then no spark at all, until it eventually felt like running. Steadily got worse over a few months, then gave up altogether. Thing was barely a year old...............
Click to expand...

Mine's been doing that since 1985... go figure. :D

Currently have 4 DMCs fitted to my various Lavs, the first was fitted in the mid-80s, no issues apart from one optical pick-up failure on the 750.  Most DMC control box failures can be traced to operator/installer incompetance.

As Tony stated, the sparking on powering up is a common feature quirk found on all sorts of electronically controlled ignition systems.

piet
 
The de witt I had installed started doing exactly that not long before it died. Would throw a spark when ignition first turned on, then no spark at all, until it eventually felt like running. Steadily got worse over a few months, then gave up altogether. Thing was barely a year old...............
Lex
 
The de witt I had installed started doing exactly that not long before it died. Would throw a spark when ignition first turned on, then no spark at all, until it eventually felt like running. Steadily got worse over a few months, then gave up altogether. Thing was barely a year old...............
Lex
Click to expand...

Yeah, they can crap out- mine did- but Uwe Witt stood by his product and sent me a new box (once he'd tested mine) in very short order.  Now that the Chinese make all the little bits that go in these electronic gizmos we'd better get used to things failing without warning. 
 
SimonR501 said:
Sorry to be lone voice in the distance........

My Witt DMC2 never kicks or sparks when I turn the ignition on.
Maybe I am just lucky?
Click to expand...
Neither does mine, can't believe there are only two lucky sods using the system ;)
 
Terry Dymond said:
Neither does mine, can't believe there are only two lucky sods using the system ;)
Click to expand...

Maybe but think about this

Do you turn the ignition on and then give the throttle a couple of twist before starting?

Or do you twist the throttle a couple of times and then turn the ignition on?

 
With the Dellortos it was just a matter of ignition on, choke on and hit the button, no throttle twisting required.
Now that I've got the Mikunis fitted, the starting procedure is a bit different but still no twisting required, still experimenting with the Miks, seem a bit more reluctant to start, most probably due to the larger bores.
 
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