I recently got a '69 Skylark convertable that's been sitting in a barn since '93. I guess it ran when parked, but dosen't anymore. The motor turns over, but won't fire. I check for spark, and nothing. I replaced the cap, coil, plugs, wires and cleaned the points and nothing. I do have 12 volts on the hot side of the coil with the key on, and if I short out the points I do get a spark from the coil wire to ground. What else should I be looking at? Tony
There are many possibilities, however if you have checked the obvious stuff you may want to check the distributor gear. There is a little drift(?)pin that holds the gear to the shaft. They can break and the dist will just spin. Mike
With the cap off I can see the distributor turn and the points open and close. I haven't changed the condenser yet. Could that be the problem, or something ground related? Tony o No:
Another thing to check, when you installed the points did you get them adjusted correctly. If your not careful they may not be closing and therefore won't short and fire the coil. BTDT! ou: Dave B
If the condensor is shorted you won't get spark. Disconnect it and see if you get spark then. Do you have 12 volts on the battery side of the coil and is the other side hooked to the points? The points short the other side to ground while they are closed creating a magnetic field in the coil and when the points open the magnetic field collapses causing it to induce high voltage into the secondary of the coil. How do you know that you aren't getting a spark? If you have a timing light with an inductive pick-up I would use that to check for spark. Just put it on the coil wire. Make sure that you are getting it off the coil first. If you are getting the spark there then go to a spark plug wire. It is really difficult to hold a spark plug to check for spark with everything else that is going on while someone is cranking the engine. Of course if it shocks the heck out of you then you will know if you are getting spark. Good luck! :bglasses:
Howdy, There is a groung strap under the point plate that grounds the plate to the dist housing if it is broke you will not get spark.
Yes I do have 12 volts to the battery side of the coil and the other end does go to the points. I rigged up something to hold the coil wire about 1/4 an inch from a good clean ground, and with the key on, points open, then shorting them together with a screw driver I do get a spark jump from the coil wire to ground. It's not a huge blue type spark, but something. As far as testing spark at the plugs, I've taken two different ones, at different times and using a good jumper, grounded the plug to a good ground and had someone crank it. Nothing at the plugs. I tried two different one to rule out a bad plug wire. I do have an induction light and will also try that. I will also check the point plate ground strap. I do see some rust around the mounting screw and after this things been sitting for 12 years anythings possible. Thanks and keep the ideas coming. o No:
I know it might sound dumb but make sure there is no grease or oil on the contact surface of the points. After you adjust the gap rotate the engine until the points close, turn the ignition off and put a piece of clean paper between the contacts and then just pull it out. An old matchbook cover works really well. Then make sure that you have a good rotor button and cap. If you still have the old one I would put it back on unless it was damaged. You can clean it up with a screwdriver or knife blade on the inside of the cap. Just scrape the contacts lightly to remove any oxidation. I know that it was already mentioned but make sure that you set the initial gap on the points, I think that it should be set to between 18 and 20 thousandths. Make sure that you have a good ground from the distributor plate to ground. You can check that with an ohm meter, just touch one lead to the plate and the other to a known ground, it should read zero ohms. If that is ok then the ground strap for the distributor is good. There is not much else in there. Good luck and let us know how things go.
You have a spark, maybe not as good as it should be, but a spark none the less. It's getting to the distributor cap but not to the plugs, right?? The only things that can be wrong from there are a bad cap/ try reinstalling the old one, even new ones can be bad. Or could be the new rotor can be bad, clean up the old one and put it back on. Also your test where you shorted the points and got a spark at the coil then had someone turn it over and got no spark, I'd run both those tests the same way, cranking the motor over. The battery may not have enough juice to give you a good spark while cranking but plenty when your just shorting the points. The points could have oil on the contacts and not making contact which would be the same as them not closing. One more thing, the ignition uses different wiring in the start position/ when you checked the plugs, than it does in the run position/ when you checked the coil so you need to know if your coil is getting 12 volts while cranking over. If it were me the first thing I'd check would be voltage at the coil while cranking. Dave B
...strange as it may sound, I was doing a routine tune-up replacing most of the stuff. When I finished, No spark to the plugs Mind you, the car ran pretty well before I abused the law "Dont fix it if it ain't broke !!" So, I started swapping back ONE part at a time ....new back to old. ....until the last piece. Turned out the new set of points just wouldn't work o No: ....replaced everything back to new except the points (which didn't look bad at all) and its running that way 3 years later (SportWagon....doesn't get driven much)
