weird spark

[m4xwellmurd3r]

So, i was pulling the plug wires on my 280z today, and i noticed something odd. the number 2 sounded like it was sparking twice as much as the rest

at first, i thought it was my ears, so i let it arc onto some metal, sure enough, it was sparking double rate what the rest were

so if it would be like this

1 2 3 spark, 1 2 3 spark

it would go

1 spark 3 spark 1 spark 3 spark

something like that

what the hell's goin on here???

[Nissanman]

If #2 is indeed sparking more than it should, it may be due to crossfire from other cylinders.

Confirm your "disorder" with a timing light connected to #2 lead.

If it has too many sparks remove the lead from the distributor cap.

Plug the timing light into the distributor cap and see if it repeats the weird firing.

If it does then the cap is crossfiring.

It may have cracked and/or formed a carbon track inside.

Maybe time for a new one:surprised

[m4xwellmurd3r]

actually, last time i checked inside the dizzy cap, it looked quite...worn?

the electrode things inside (that send the spark to the wires) looked like they've seen better days. I wouldn't be surprised if it was the original one from 78.

I needa buy a timing light it's the one thing i haven't gotten yet.

the plug wires do appear to be new, so i think it might be the dizzy cap.

I'll buy a timing light tommorow after i get my 30 day temp tag for my car.

there's one other problem. I dont' think my pully has it's timing mark anymore o_o what should i do about that? since i have to pull off my dizzy cap (most likely) should i set it to TDC and mark the pully? (if i set it to tdc, with the dizzy pointing where it should and everything, would that be the 0 point on the timing ticks?

[Nissanman]

I doubt that the pulley has lost it's timing marks, do you mean the pointer that attaches to the front cover?

There is another thread covering the timing marks for non-A/C and A/C crank pulleys.

[The notch in the crank pulley is only helpful if there is a reference pointer on the engine front cover.]

However, removing and replacing the distributor cap can be done without disturbing the ignition timing i.e. it will be the same after the exercise as before.

What you do need to be careful with, is the lead connections to the new cap.

They must not get changed in firing order.

The L6 engine has a 1 - 5 - 3 - 6 - 2 - 4 firing order.

So once you get your new cap, orient it correctly to the distributor body [it goes on only one way] and swap the leads over, one by one, and fit them in the same order to the new cap.

If it is the original cap from 1978, I would complain to Nissan about their poor quality partsROFLROFLROFL

Picture is here: -

http://www.classiczcars.com/forums/attachment.php?attachmentid=18774&d=1183956284

[m4xwellmurd3r]

oh, so it's a notch. I still have the front cover notches, but i didn't know the pully was notched. that makes it easier. (every car i've had, it was a painted mark)

I'm wondering if maybe the cap has aluminum electrode things in them (what are they called?) and that they have erroded away. they're deffinetly not brass.

yeah, i actually marked my wires to make sure i remeber which goes where.

i'll write down the order in my book i have (i keep a notebook in my car, describing certian mantinance things, such as valve adjustments, and plans on what needs to be done to the car) I'm going to buy a chilton manual soon as well. (i've been using an online repair manual, which is almost as good.

[Nissanman]

Just clean up the crank pulley notch and paint it with a drop of white paint.

That will make it show up a lot better when using a timing light.

Those hi-tension posts sound like they are trashed, try for a genuine replacement cap, that may have brass terminals.