The Stovebolt Site Forums The Shop Area Engine Shop truck wont fire?

Been driveing my truck daily for over a year.Saterday morning i went to fire it up to go fishing and nothing.Im not getting any spark at the plugs.Checked with my fingers even and not a tingel.Atest light with the key on shows curent on both sides of the coil and and on the wire comeing out of the distributor.Did not see any spark with the engine cranking with the key on while holding the coil wire to the block.Should i have current at all 3 locations?.Where the heck do i look next?new coil?This is on a 54 235.

SLow....hot tip....coil for 6 volt, 17 bucks at Mills fleet farm (if you are running 6V). Go to the OLD tractor section....They stock stuff for the old Farmalls and the like ..including coils....also, check your points and cond.

Good Luck.

Its blains farm n fleet here but they carry the same stuff.Id like to nail down what it is before i start replaceing stuff.

Try this. Take off distribuor cap. Turn engine until the points are open. With the ignition on, use a screwdriver blade and touch across the open points while holding coil wire close to the engine block. You should get 1. sparking at the screwdriver across the points and 2. spark jumping from coil wire to block. If there is no spark across the points, you're not getting current to the points. If they spark and no spark at the coil wire, try another coil wire, there may be a burnt section in the carbon trace wire. If a known good coil wire doesn't produce a spark, you could have a shorted condenser or a bad coil. If you get spark from coil wire, then it isn't being distributed to the plugs. Check and see if the shaft is turning. Could be stripped gears or a sheared pin holding the gear to the shaft. If shaft spins, check rotor tip, distributor cap. The problem has to be somewhere in this proceedure.

Truck Tinker

I've seen rotors burned through right to the dist shaft. This would cause a no spark condition.

JS

This one sounds like burned/dirty points. The test light will show voltage all the way to the points in this case, which shows you've got a good circuit. Take the distributor cap off, bump the engine over with the starter, or turn it with the fan until you see the points open, then touch a jumper wire from the distributor primary terminal to ground. You should get a spark from the coil wire. If the points are discolored, you could try cleaning them, but a simpler, and more effective fix is to replace them. Put in a condenser while you're at it. They're inexpensive, and hard to test without some pretty sophisticated test equipment. Once the points are contacting properly, the test light should be off with the points closed, on when they're open. if the points aren't opening when the distributor shaft turns, the rubbing block has worn, and you need to adjust the point gap, or dwell, if you've got a dwell meter. (More accurate with a dwell meter).
Jerry

Acually i have the equipment to check a coil and condensor ,i justdont know how to use them.I ve got an old sun machine but ive yet to find a manual.When the truck first wouldnt start i thought it was moisture and pulled the cap and moved the points.They did ark.Last night i replaced the coil wire and had no spark.Today i opened the points again a couple of times and they arked.Put the cap back on cranked again and the darn thing started.Now i need to figure out why be fore i get stuck on a loging road out in the tolees.Im on vacation next week and need the truck to haul my boat around.Also i could use a quick lesson on how to use a dwell meter and set the dwell on a 235.Where does the red and black lead go?Thanks,Ron.

Red lead goes to the coil (-) terminal, black to ground. Adjust the point gap closer for higher dwell, wider for a shorter dwell reading. Actually, a dwell meter is just a voltmeter which reads the average voltage between points open and closed. With the points open, you'll see full battery voltage, and zero when they're closed. The longer they stay closed, the lower the average voltage will be. The meter is calibrated to read 60 degrees with the points closed all the time on a 6-cylinder, 1/6 of the 360-degree full turn of the distributor cam. On a V-8, the points-closed reading will be 45 degrees. Best coil saturation happens at about 66% dwell, 30 degrees on a V-8, or about 40 degrees on a 6.

Edit: Always carry a spare set of points and condenser, and a screwdriver in the glove box! You can do a field setting on point gap with a matchbook cover or a business card to get you running in an emergency!
Jerry

Just a guess:
Have you checked the pass through nut and insulator block on the distributor for integrity? It sounds like it is either grounding out or opening up.

A standard dwell meter is connected with the black lead to ground and the red (+) lead to the points or - terminal of the coil.

Check the wires going into the distributor. They move alot and could be just barely making contact. Messing with the distributor could have put them back in contact temporarily.
I've seen this on H.E.I. before,
Scott

Take a good look at the insulator block like Josiah and 48bigtrucks mentioned. See if the wire from the condenser is down all the way on the insulator lug inside of the distributor. If it happens to be sticking up, the cap can push it down far enough to make contact with the distributor housing and ground the voltage before it gets to the points.
-
While the engine is running, wiggle the wires to see if you find a connection that causes the engine to stumble or die.
-
Make sure you have the wheels securely blocked so the truck does not roll away with you working under the hood
Be safe

Everyone seems to be concetrating on the points. I would be tempted to replace cap, rotor and a new set of spark plug wires. After you get a spart it has to go through these get to the plugs. Just a thought