L24 trouble after installing Pertronix Electronic Ignition

[Cbb]

I've got a 1972 240z that I converted the ignition from points to electronic usic the Pertronix Kit with the ignitor and the 3.0 Ohm flamethrower coil. I bypassed the Ballast Resistor and fired it up. At first, it was having a hard time with the idle. We had it idle enough so that we could check the timing. At full retard, the white mark is right on the arrow, so the timing is spot on. The idle is at 700 RPM. When I took it out for a test drive, a little past 3k RPM, at about 3,400, it would start to misfire/backfire. It felt like it's limiting itself from going 4k+ RPM. I have no idea how to approach this.

*Before I switched to electronic, my points were worn, and on the freeway, my revs would drop to zero, then it would go back to where it was before; otherwise, they were running well.

Edited March 9, 2014 by Cbb

[NewZed]

Did it rev past 3,400 RPM with the points?  You've described two different regimes so there's no comparison of old versus new.  And why were you idling on the freeway?  "on the freeway, my idle would drop to zero, "

[Cbb]

On points it would go beyond 3,400. Basically, it would rev as high as it would want.

As for Idle, I meant that my RPMS would drop to 0, from say at 3,000 in 5th, then I would let off the throttle, then it would go back up to where it was.

Sorry, poor choice of words, I'll edit that right now.

Edited March 9, 2014 by Cbb

[NewZed]

Did you buy the Pertronix Ignitor new?  Cutting out at high RPM is a typical sign of a bad ignition module.

 

Also, white mark right on the arrow doesn't mean much.  There should be numbers associated with timing, 10 degrees BTC or advanced, for example.  Being picky but it's hard to tell what your situation is.

 

What about the rest of the parts - plug wires, plugs, rotor, cap.  Are they new also or the old pieces?  Did you follow the Pertronix instructions or wing it based on what looked right?  Details.

[Cbb]

I bought the Pertronix Ignitor and Coil as a kit from MSA. Chances are, it's probably a faulty ignition module, because it does happen.

as for the parts, plug wires are give or take, a few months old NGK, Rotor is about 2 weeks old. I'm going to assume plugs are as old as the wires.

I followed the instructions, reading it thoroughly and double,triple checking everything.

I'm not entirely sure about the timing, other than I guess it's TDC? (it's exactly inline with the 'arrow') Before, it was slightly advanced, using points.

Also to note, the points were worn, in a sense that there is a mound at one side (Uneven), so my friend decided to take them out, and sand the contact points flat, then set the gap at .016.

 

And if it's worth a mention, Carbs haven't been touched since we sanded down the contact points, a few weeks back.

 

That's all I could think of at this moment.

Edited March 9, 2014 by Cbb

[beermanpete]

Did you check the operaton of the vacuum advance and centrifigul advance? Perhaps one of both are in need of service.

 

When you say "RPMS would drop to 0", I assume you mean engnine stops running and the tach indication goes to 0. This sounds like a problem with the primary ignition circuit. Perhaps the worn points were not the only problem. You might have a bad connection somewhere that did not get "fixed" by installing the Pertronix.

[Cbb]

After asking around some forums, and meeting some fellow Datsun owners who have switched to pertronix, they agreed to help me solve my problem. Prior to getting my car 'fixed' I changed my sparkplugs to NGK BRP6ES, with a .040 gap, checked my plug wires to make sure they're still alright, and checked all the connections.

 

1.) They checked the pertronix ring itself. Now there was a lot of play between the distributor shaft, and the magnetic ring. Essentially, when the car would start running in high rpms, the ring would 'free float', or the shaft would spin independent of the ring, causing the backfire.

 

2.) checked the timing. According to them, the timing with the pertronix kit, needed to be 'more advanced'. My friend had 30 degrees in advance before it worked correctly. So we went from 10 degrees, to about 20 degrees advance

 

3.) Carbs were sync'd and the mixture is set. Apparently, I was running rich in cylinders 4,5,6 and they were somewhat surprised how the car even ran at that stage.

 

So it was either one, or the combination of all that fixed my 'rev limiting' problem. I believe that the play between the shaft and the ring caused the problem, because the ring couldn't exactly be 'secure' down on to the shaft.

 

As it stands, the engine is now running how it should be..... when I'm on wide open throttle. The car is now revving past 5k, and it feels punchy.

 

Now, another problem arose, but I think it's the fact that we didn't set the timing, until AFTER we sync'd the carbs and adjusted the mixture. But he said he'll fix it the next time he's around. When I'm lightlty on the throttle, at about 1500~ rpms in 3rd gear, it bogs a bit, as if it's not receiving enough air, even though it still continues to increase in rpms. It's not until you rev it up higher, then it goes away. But it comes back when slowly accelerating and going through gears.

 

So the plan now is that my friend will be bringing his pertronix kit, to see if I have some sort of faulty fitting ring, and if it would work. If his works perfectly, while mine doesn't, then I've had a faulty pertronix module this entire time. If his doesn't work, we'll be going back to a new set of points. But of course, before we do all of that, we'll have to match the carbs to the timing first, and see where that lands us.

[Cbb]

Problem solved. Idiot me, made a simple idiotic mistake. Bought and installed sparkplugs that were 1 range colder. Went with the correct plugs (BPR6 series with a .044 gap), now works fine.