distributor cap tracking

[jaxs]

Went to get it and nothing not a peep. .

I think I speak for most people here when I say "not a peep" would indicate no click or engine turning over. I would have sworn you said it was "peeping" earlier in this thread. To get the best help,you must try and be precise when describing problems,beit with a tractor,a sick cow or bad haircut. Above all else,don't change symptoms unless you clearly say they are a new development.

 

[TractorGuy]

When was the last time you replaced the cap AND rotor? These should always be replaced as a set.

Does the distributor shaft have any side to side movement? Any play in the shaft will prevent it from maintaining a constant dwell or gap between the rotor and cap contacts.

 

[Bandit2026]

Lets do this again. The coil, points, condenser twice rotor and cap. This thing ran fine when I put it in the barn, two months later it would not fire the plugs. Engine would turn over but would not start. I have power to the top of the coil, with a test light attached while trying to start it dims slightly but does not blink.
I have power at switch, through amp gage and through resistor. Can find no burnt wires any where. Have had distributor off a half dozen times did all checks that was suggested and it will still not run.

 

[jaxs]

I'll remind you that key on is one circuit to coil and while cranking is a different circuit. Just for grins,put a jumper wire from - battery post to coil then try starting (ASSUMING tractor is still positive ground). I have a suggestion that will ease checking for spark going to plugs,without risk of :shocked:
Free's up your hands and can be seen while at driver's station attempting to start.
AutoZone Part Number 25227 OEM inline ignition spark tester. $8.99
Back to the task. "IF" coil is receiving 6+ volts with engine off and key in run position,it will receive even more while generator is operating. That will burn a coil up.
I've used the "blink test" on side distributor with light between coil and points. I'm not sure how it works on front distributor. Anyone tried it and found it to work on side distributor?
Hang in there,take it one bit at a time,you can wup it.

 

[Bayfisher]

will the tractor spin over right now ? if yes use a VOLT METER, not a test lite to measure the voltage at the coil positive [+} post when cranking the engine, if voltage is at least 5 volts then remove the dist cap and rotor [ with the key off ] rotate the engine till the points are fully open, grab the top of the dist shaft [ where the rotor fits ] and attempt to move the shaft towards and away from where the points ride on the dist cam, is there any slop in the dist shaft / or does the points gap increase or decrease when moving the shaft ?

 

[TractorGuy]

As far as using a test light goes it should blink on the points side of the coil. If it remains lit on the points side then the points are not grounding the connection. I'm not familiar with the 8N setup but if it has a post passing through the distributor body for the wire it needs to have proper insulation. It cannot be insulated with rubber. It has to be nylon or a non conductive material. Rubber has a carbon content that is conductive and will short out the connection. (I learned this the hard way)

 

[TractorGuy]

This doesn't apply to an 8N. Rubber can mess up high voltage, but it won't short out 6 volts.

It will prevent a 12v points system in a Volvo from firing. I know this to be a FACT!

 

[TractorGuy]

You either has some pretty contaminated rubber or the post on the distributor failed. GM, Ford and Chrysler all used rubber insulators (grommets) for decades.

View attachment 599023

That photo is of an insulated wire passing through a rubber grommet. NOT what I was referring to. I am talking about a post in the side of a metal housing with insulators. Like I said, I don't know that the 8N has such and arrangement. I can say with absolute certainty that any insulator that comes in direct contact with the wire terminal connected to the points CANNOT be black rubber. Rubber grommets work fine for preventing chafing of an insulated wire.

 

[Bandit2026]

How do I check the coil?

 

[Bandit2026]

I really don't know how we got on to Volvo distributors but I was reading another forum and they talked about the amp meter wiggle when you crank the engine. He said that if it didn't wiggle, something in the primary circuit was not grounded. Any ideas?