No Spark to plugs...please read and help

[Guesseral]

My first attempt was with a 12volt coil that had no resistance...that thing got so hot it would have melted the skin off my hand. Needless to say, since I've changed to the one I put the picture up of, it doesn't really get hot at all. It might warm up a few degrees, but it stays much much cooler.

Has the tractor ran since you installed the new coil?

 

[nj82tj]

Yes, it has ran with its current set up (to include the new coil). The last time it ran was about 2 weeks ago. It fired up with no hesitation at all and I let it run for about 45 minutes. I think I stalled it out when I was working the throttle though and since then it has not run.

 

[Guesseral]

Yes, it has ran with its current set up (to include the new coil). The last time it ran was about 2 weeks ago. It fired up with no hesitation at all and I let it run for about 45 minutes. I think I stalled it out when I was working the throttle though and since then it has not run.

Oh well it was a thought. It's really hard helping to trouble shoot a problem without being there! LOL

 

[nj82tj]

Oh well it was a thought. It's really hard helping to trouble shoot a problem without being there! LOL

Amen to that! I appreciate all the help though!

 

[Soundguy]

If you didn't install a resistor you may have burned out your coil. I would think that be the issue if it worked before converting to 12 volts and then ran a few times after. Even 12 volt coils require the resistor, they start on 12 Volt but run on 6. No resistor would put 12 to the coil all the time.

Sorry.. but that's simply incorrect here in this application.

a napa ic14 / SB coil is a native 12v coil. requires no resistor.

you are evidently thinking of a later 65+ 3 cyl design that used a 6v coil, 12v system, and a resistor wire. during starting, the coil got full voltage int he start position.. once started, in the run position, the coil rcvd power thru the resistor wire.

this system is NOT like that... 4 cyl fords 53-64 are my specialty... got dozens of them in the barn. they were all 6v gas, or 12v if diesel, ( 1959 ) from the factory.. no 12v start / 6v run jobs oem...

soundguy

 

[Soundguy]

How much voltage should be at the coil when I'm cranking over? I tested that last night and was at about 8.5-9volts when cranking. I am also going to get a new distributor cap, dust cover and clip to try tonight.

I agree with DR dave. when you see a system that tries to start the moment you let off the starter.. it usually menas low power to the coil.

wow.. 8.5-9v atr the coil.. that's pretty low!! I would think it should be more like 10v.

double check your wireing to make sur ethere are no hidden resistor or resistor wire feeding it.

here another test you can do.

got a spare battery? hotwire the coil from a spare car battery.. or lawnmower battery.. ie.. ground the battery to chassie, and run hot wire to coil primary.. now crankt he tractor over.. see if spark is hotter and she starts. post back

 

[crlytlfrm]

Have you double checked your point gap?

 

[Jerry/MT]

Look, the OP said he had the requisite FAT, BLUISH-WHITE SPARK at the coil high tension lead indicating that the primary ignition circuit IS NOT THE PROBLEM! Generally the starter will pull a 12V battery voltage down to 10V+/_ during a start so that's not anything abnormal.

IF, with the points closed and the key on, the the primary voltage at the coil terminal is less than the battery voltage OP should not be seeing the FAT, BLUISH -WHITE SPARK that he claims to be seeing due to an abnormally high resisitance in the primary circuit. So either he has the the requisite spark and the problem is in the high tension system downstream of the coil, OR he doesn't have the requisite spark at the high tension lead and his problem is in the primary circuit.
Can't have it both ways.

You can eliminate part of the primary circuit by jumping the coil to battery directly and then checking the spark or trying a start. Or, if you have a spare battery or a vehichle with a 12v system as Sounder suggests, you can jump from it directly to the coil and eliminate the starter drawdown and the primary ignition circuit to the coil.

 

[Soundguy]

dizzy wasn't snatched out of this machine was it?

with #1 on tdc comp stroke.. is the rotor pointing at the tower going to that plug?

has dizzy been repalced.. or parted together.. perhaps another advance? advance from the 00 to the naa are IIRC not compatible..

 

[Dr Dave]

Good ideas, to try another battery, hooked up to coil and engine ground.

If this does not work, maybe new coil has an issue. I am not familiar with this coil. How can it provide enough voltage at normal crank voltage of 10.5 to 12V, and operate at run voltage of 13.5 to 14V and not overheat?
I read on anouther forum, that NAPA has 2 of these coils, US and China models, one has issues! Which do you have?

Good luck, keep at it!

Dave

 

[bigdeano]

It's an old tractor, probably has a lot of hours on the engine. If the spark isn't going through the HV part of the distributor, it's probably out of time and the rotor doesn't line up with the cap terminals. Maybe the distributor gear is worn, or even the cam timing gear slipped a tooth. Like others have suggested, check the timing and make sure the rotor is pointed at the cap terminal when it sparks.

It stalled while it was running, so something failed.

 

[EE_Bota]

It's an old tractor, probably has a lot of hours on the engine. If the spark isn't going through the HV part of the distributor, it's probably out of time and the rotor doesn't line up with the cap terminals. Maybe the distributor gear is worn, or even the cam timing gear slipped a tooth. Like others have suggested, check the timing and make sure the rotor is pointed at the cap terminal when it sparks.

It stalled while it was running, so something failed.

Good point. I think is it time to address rotor position to be certain.

 

[Soundguy]

i'd be VERY surprised if both were not chinese.

there is an IC14 and an IC14SB same coil.. one is 50-60$ and is the gold line.. the other is 16$ or so and is the value line. black coil.. white printing.. other spendy coil has a decal on it..

both are oil potted coils.. oil potted coils handle heat much better than air, tar or epoxy potted coils, with respect to heat disipation.

running the numbers real quick looks like it's running with a 20% tolerance. I don't find that uncommon... lots of automotive electronics run 8-15v since charge votls will be as high as 14.4 to 14.7 in some cases, and at startup.. most electronics won't see over 10v usually.

soundguy

 

[Soundguy]

It's an old tractor, probably has a lot of hours on the engine. If the spark isn't going through the HV part of the distributor, it's probably out of time and the rotor doesn't line up with the cap terminals. Maybe the distributor gear is worn, or even the cam timing gear slipped a tooth. Like others have suggested, check the timing and make sure the rotor is pointed at the cap terminal when it sparks.

It stalled while it was running, so something failed.

did the naa use a fiber cam gear or metal one? I know on the N fiber gears were used.. and could strip out.


here's another thing to check in case it was or wasn't mentioned.. look at nose of hyd pump/tach drive and make sure it turns evenly and doesn't slip and jerk when cranking..

 

[Jerry/MT]

It is most like sized at the starting point toprovide the maximum spark voltage at the redued battery voltage and you just have the capability for higher spark voltage IF it's Needed at full battery voltage. Remember the coils only delivers enough voltage to make the spark no matter what it's rated at.

Another trick is to use a resistor in a parallel circuit that puts resistance in the primary circuit when the key is in the run position and when the key is in the start position, no reisitance is in that other circuit to the coil. Used to be common on Chrysler products and others.

 

[Jerry/MT]

dizzy wasn't snatched out of this machine was it?

with #1 on tdc comp stroke.. is the rotor pointing at the tower going to that plug?

has dizzy been repalced.. or parted together.. perhaps another advance? advance from the 00 to the naa are IIRC not compatible..

Usually, the advance does not come in at low rpm's like cranking speed. If the engine is timed "correctly" even with a stuck advance it should start but be doggey at higher rpm because of lack of advance. The OP is saying fat spark at coil high tension output and no spark at plug wires. So that would be an out of time situation. Did he time in on the exhaust stroke??????

 

[Soundguy]

It is most like sized at the starting point toprovide the maximum spark voltage at the redued battery voltage and you just have the capability for higher spark voltage IF it's Needed at full battery voltage. Remember the coils only delivers enough voltage to make the spark no matter what it's rated at.

Another trick is to use a resistor in a parallel circuit that puts resistance in the primary circuit when the key is in the run position and when the key is in the start position, no reisitance is in that other circuit to the coil. Used to be common on Chrysler products and others.

yep.. common bypass setup.

3 cyl fords run power straight to the coil.. in start and run power is thru a resistor wire. 6v coil on a 12v system.

 

[Soundguy]

only reason i mention advance is I have seen someone put the advanc off a different unit on.. that turns a different direction.. and the rotor would be pointing like halfway between posts.. op had good spark at coil tower.. and when hooked to dizzy. would get leakage from center tower of coil over to the screw terminal ont he cover of the coil as there was no closer gap for the spark to jump.. IE.. it was tracking along the coil top to find a gap small that betwixt the 2 towers.

I was just wondering if the op had his dizzy removed and rebuilt or something..

on another note. the later had the hex drive right.. but the naa drive is different? it's not a pinned setup is it? (slipped drive? )

 

[nj82tj]

I have yet to pull the distributor and look at any of thoes internals. I just picked up a new cap and dust cover to be sure. It did not start. The dust cover has the fiber washer on it. I tried to direct wire a second battery right to the coil, no different. Um, what else...points are gapped, I did check timing by pulling the plugs and using the thumb over hole method. Every wire seems to match nicely with the rotor. I did loosen the distributor and turn it about a 1/8" at a time just to try and get it to hit. No luck, it's now back in its original location. I replaced the condenser again while I was in there. No luck. I do however notice a weak spark at the plug (when grounded on the tractor just for inspection) when the starter is almost done cranking. I hadnt noticed that before. Still won't turn over though. I'm getting close to pushing her into the street and letting my neighbors pond take care it it...it's so frustrating because it makes no sense! Thank you again everyone for all your input thus far. If anyone else is bugged enough by this, feel free to message me and I'll give you my phone number so we can talk directly. I'm about out of options here.

**the weak spark I'm referring to is via the dist. cap**

 

[Soundguy]

back to no spark now?

and now she won't turn over?

sounds a whole lot like a bad battery.. bad connection.. poor ground.. or bad starter bushing making for an excessive draw.