ignition system voltages

[AceOfDiamonds0]

I just rewired my '72 510 2 door and I've double and triple checked all the wires going to and from everything so i know wiring isn't an issue.

 

My issue is the car won't start. It has the L16 with single points dizzy. I just replaced the ballast resistor and i have 11.8V going into the resistor and 5V coming out and going to the coil and also to the plug wires. The spark plugs look pretty black so I'm going to get new plugs wires tomorrow morning.

 

I know I'm getting fuel into the carb because I can see it go in when i open the throttle. Its a 32/36 weber.

 

It might just be the plugs but i wanted to post something on here to see if i might be missing something and to see if I've got the correct voltages everywhere.

[datzenmike]

You need spark and fuel. You say you have fuel flow so I'll skip that.

 

Spark:

Pull any plug wire off and stick an old plug in the end and lay on a grounded surface like the valve cover. Have someone crank it over and look for spark. Spark? yes or no???

 

Yes.... change the plugs

No.... pull the wire from the top of the dizzy that come from the coil and do the same. Spark or no?

 

 

Yes.... the problem in between the coil wire and the plugs. Distributor rotor missing or broken. Cap cracked or broken. Look for carbon tracking where spark is jumping to ground.

No spark.....

Confirm that there is voltage at the positive side of the coil when cranking

Is dizzy grounded? Don't assume the hold down bolts do that job. Are they tight? Run a separate ground with to the dizzy case.

Are the points opening and closing? Take cap off and watch while cranking???

With the key ON,  momentarily ground the negative side of the coil.... this should give a spark.

The capacitor can short internally forcing a continuous ground so the points are by-passed. Disconnect the capacitor and try.

[AceOfDiamonds0]

Ok I did most of that already but it couldn't hurt to go over everything once more just to make sure I'm not missing anything.

 

Also the 11.8V to the ballast resistor and 11.8V to the positive side of the coil when key is on start. And then 5V from the ballast resistor to the positive side of the coil is good right?

[banzai510(hainz)]

Thats close enough for the voltage for it to run. I run 2 ballast resisitors and I get 3 volts at the coil.

 

Remember you have a HOT START wire that should go to the + side coil. when the key is in start

This is the Blk/Blu wire. The blk/blu wire is shorted to the blk/ grn under the tape with a chezszy c clip splice.

 

So what happens when you put the key in to START you get Battery volatge right to the coil as the battery is suckking down alot of voltage.(The Ballast is bypassed) then when key goes back to ON the battery voltage runs thru the ballast then out to the coil.

 

 

really all I would do is pull the center coil wire and place near(1/4 , 1/8 inch) the strut tower bolt and hit the key and see if you have snapping sparkk. If not then ck the points also and condensor.

[datzenmike]

Question not answered. Got spark??????????

[AceOfDiamonds0]

Ok I've got spark to all cylinders and I've got fuel going in. It tried to start but didnt fully light so I'll just have to keep working with it.

[banzai510(hainz)]

Is the hot start wire hook up as i noted?????

 

then make sure the your dizzy is timmed correctly.

 

 

Why not start from the bigging for use. Was this running before?

If you put it together make sure the cam is timmed the Dizzy(oil pump drive) is timmed.

 

valve lash of on the rockers.

carb intake tight.

 

then it should light off. pour soem car down the carb.

 

you got the fire order correct if you have the plug wires off.

[AceOfDiamonds0]

The hot start wire is hooked up.

 

I havent played with the dizzy timing.

 

It was running a little rough before I rewired it and I havent changed anything from how it was before other than the wires and such.

 

I got the firing order right. 1-3-4-2 CC

[AceOfDiamonds0]

Finally got it running for the most part. now just fine tuning.

 

I threw in a pertronix 3 ohm coil and replaced the points with an electronic conversion kit and it still didnt start. I played with the timing some more and got it to run very rough but enough to use a timing light. The timing was at 65 degrees BTDC! YIKES!!! I adjusted it so it's running about 15 degrees BTDC.

 

I'm not sure what the timing is supposed to be at. I thought it was supposed to be 12 degrees but like I said I'm not sure.

 

I put the timing light on plug wires for #2 and #4 and it was very inconsistent as if it was missing but it didn't sound like it at all. I'm going to put the points back in there and see if it runs any cleaner.

[AceOfDiamonds0]

Another question. What spark plug gap and point gap should i have when running the stock single points with the stock coil and ballast resistor on this L16?

[datzenmike]

Plug gap 0.032"

Point gap 0.022"

Timing 12

[AceOfDiamonds0]

Ok so here's something interesting.

 

The electronic conversion kit turned out to be a bust. It's a pertronix kit and everything bolted in just fine but the magnetic ring that goes on the spindle underneath the rotor didnt fit very snug so plugs #2 and #4 were very inconsistent.

 

So I bought a new set of points and put those in with the new ballast resistor that I bought and the stock 1.6 ohm coil. Now with everything how it was, it starts but doesnt stay running unless I leave the key in the 'start' position. It dies as soon as the key is switched back to just 'on'. As if it lost power.

 

I checked all my wiring again and its all correct and I had the proper voltages everywhere. So I just put the wire going into the ballast resistor to the positive side of the coil, bypassing the ballast resistor all together and started it up and it ran fine. Except now I've got a constant 12V going to the 1.6 ohm coil and a constant 12V going to my points now.

 

I'm hearing thats not a good thing to do for extended periods of time. I.E. burning up the coil and or points a lot quicker.

 

The new coil that I bought for the electronic conversion kit is an epoxy filled 3 ohm pertronix flamethrower (not a 2 or 3). Obviously the constant 12V into the 3 ohm coil would be fine but would the points be able to handle the output of the flamethrower?

[datzenmike]

Ballast resistor broken or not connected/wired wrong.

[datsunaholic]

The points need the lower voltage, it's the higher voltage that burns them up (this is contrary to the Pertronix, where higher current burns them up.  Adding a ballast resistor reduces both).  The coil may or may not be OK with full 12V (depends on the coil- ones marked "Ballast Resistor Required" logically, require a ballast resistor, or they'll overheat.   HOWEVER... a 3-ohm Flamethrower coil has the resistor built in.  Since the points only draw through the negative post on the coil, a 3-ohm coil is the same as a 1.5 ohm coil + a 1.5 ohm ballast resistor connected in series.

 

It's possible that A) you have the ballast resistor wired wrong, or B) the ballast resistor is bad.

[AceOfDiamonds0]

So running just the 3 ohm flamethrower without a ballast resistor is ok with the points correct?

 

The wiring is right I've checked it and have had a few other people check it so I know its not the wiring.

[banzai510(hainz)]

So running just the 3 ohm flamethrower without a ballast resistor is ok with the points correct?

 

Might be harder to start. as you still have a 3 ohm Flamethrower coil. stock was 1.6 ohms and its bypassed durin the start cycle. this set up you have when you load down the battery in start the 3 ohms is still there making even less current to the coil.

 

Pertronix are fine and if you used the stock coil and ballast it shoud work.

 

the statement of 2&4 not consistance has noting to do with the pertronix unless the magnerts fell out. they are 90deg from each other. either your wires or cap, bad. I I highly even dought that.However the magnet should fit snug. unless this was a dual point L16 dizzy and I notice they dont fit on them.

 

put soem tape under the magnet ring to make it firm. Then you can adjust the timming later for the difference.

 

 

do not run the ballast and the 3 ohm together!!!!!!!!!!

persoanlly the 3 ohm Flamethrower is NEVER needed. the stock set up is better for starting as your throwing more current at the coil bypassing the ballast during the start cycle.

Remember during start you battery is going to like ubder 10 volts as the starter is SUCKING up alot of Juice.

 

 

you read my #4 post on how this works.

this is a 15min job

 

if your car stops running when key is On then thn you dont have 12volt at the coil.

 

Put key to on make sure you got 12volt to the blk wht wire to the ballast then to the othersidew of ballast then to the coil.

 

when car was running like 65deg TDC. You sure? thast like a spindal tooth off.

You sure the oil/distributor is set right on this? You should be in the middle of the timming slot and not cranked. idle below 1000 also

 

http://community.ratsun.net/topic/17444-electronic-ignitions-for-l-motors-4-cyl/

[banzai510(hainz)]

oh wiggle back if ignition switch also.The plug. this soemtimes will be it.

 

car runs in start then shuts off when key goes back to On

[AceOfDiamonds0]

This is the distributor with the new set of points in it.

 

[AceOfDiamonds0]

It honestly would not surprise me if it's off a tooth. I keep finding one thing after another thats either backwards or missing!

[banzai510(hainz)]

put motor on TDC Zero on crank and the rotor should be pretty much right on #1 plug wire.

 

Ez to ck out.

[AceOfDiamonds0]

Yeah that's how I got the timing back to 14.

[banzai510(hainz)]

I run around 7-10 deg but just depending on gas if you get more timming thats fine.

rember there is a 8mm bolt underneath the dizzy where you can recenter the timming plate to get more adv or retard before you bolt down using the 10mm bolt.

[AceOfDiamonds0]

Yeah I've been all through that dizzy quite a few times trying to get it right. I think it should be alright now.

 

Thanks for the help guys.

[420n620]

Yeah I've been all through that dizzy quite a few times trying to get it right. I think it should be alright now.

 

Thanks for the help guys.

so you got it running now ? If so, what was the problem.