Damon
05-12-2007, 10:03:38 PM
For the sake of argument, let's say this relates to an engine in an early 2nd gen F-body, OK?
I went out to start up the engine after sitting all winter on a trailer, er um... in a garage. I knew it wouldn't start becuase it didn't when I put it away for the winter (it was too cold to diagnose and fix it when I was putting it away). A few typical diagnostic tests showed the problem was little or no spark, even at the coil wire. Wouldn't even try to fire on a shot of ether.
Being a points system there's just not a heck of a lot that can go wrong. Coil, points and condenser is about all there is to the system. Before I messed with it I decided to rule out a bad power supply to the coil. I just disconnected the power wire from the harness and ran a temporary wire straight from the battery to the + terminal of the coil to assure full voltage- still nothing. I checked the points gap and it was OK around .014" so that wasn't it. I worked the points manually with my finger from this point forward since I didn't have a helper (unless you count my 2 year old son). Doing so produced no spark or the occasional weak one.
I had an old canister coil laying around so I dropped it in- no change. I even had a condenser around from something else so I jerry-rigged it in temporarily- still no change.
One last thing to check- continuity between the negative side of the coil and ground with the points closed. It read somewhere between 300 ohms and an open circuit. I wiggled the points contacts against eachother and occasionally I would get it down to double-digit ohms range- but definitely not close to zero like it should have been.
Popped off the points and took a look at the contacts (I need reading glasses to do that now). Black with hints of white corrosion around the edges. Not good. I didn't have another set of points laying around and no time to get out to the store. I dug DEEP into the tool box and found my old buddy I haven't used in probably 15 years- A POINTS FILE! C'mon- admit it- you haven't used a points file in a long time either, if you ever owned one in the first place.
A minute or two of dressing both points contacts to shiny metal and back in they went. Reading zero ohms in the points-closed position now. Reset the gap, reinstalled the original coil and condenser, buttoned it back up and turned the key. The old boat, er um... Camaro, fired up and ran better than it has it years! Set final gap via dwell meter and made sure the base timing was right again as the final step in my "high tech" ignition tune up. READY FOR ANOTHER SEASON!
I had installed those points new about 5 years ago and I don't run this engine but maybe 10 hours per year, so it didn't seem likely the points would have been fouled up in such a short time, but they definitely were.
If you still run an old points distributor in your ride you should probably consider a fresh set of points every year, even if you don't drive the car very much. Seems that sitting unused can cause as much deterioration in them as high mileage can, especially if it gets stored outdoors.
I went out to start up the engine after sitting all winter on a trailer, er um... in a garage. I knew it wouldn't start becuase it didn't when I put it away for the winter (it was too cold to diagnose and fix it when I was putting it away). A few typical diagnostic tests showed the problem was little or no spark, even at the coil wire. Wouldn't even try to fire on a shot of ether.
Being a points system there's just not a heck of a lot that can go wrong. Coil, points and condenser is about all there is to the system. Before I messed with it I decided to rule out a bad power supply to the coil. I just disconnected the power wire from the harness and ran a temporary wire straight from the battery to the + terminal of the coil to assure full voltage- still nothing. I checked the points gap and it was OK around .014" so that wasn't it. I worked the points manually with my finger from this point forward since I didn't have a helper (unless you count my 2 year old son). Doing so produced no spark or the occasional weak one.
I had an old canister coil laying around so I dropped it in- no change. I even had a condenser around from something else so I jerry-rigged it in temporarily- still no change.
One last thing to check- continuity between the negative side of the coil and ground with the points closed. It read somewhere between 300 ohms and an open circuit. I wiggled the points contacts against eachother and occasionally I would get it down to double-digit ohms range- but definitely not close to zero like it should have been.
Popped off the points and took a look at the contacts (I need reading glasses to do that now). Black with hints of white corrosion around the edges. Not good. I didn't have another set of points laying around and no time to get out to the store. I dug DEEP into the tool box and found my old buddy I haven't used in probably 15 years- A POINTS FILE! C'mon- admit it- you haven't used a points file in a long time either, if you ever owned one in the first place.
A minute or two of dressing both points contacts to shiny metal and back in they went. Reading zero ohms in the points-closed position now. Reset the gap, reinstalled the original coil and condenser, buttoned it back up and turned the key. The old boat, er um... Camaro, fired up and ran better than it has it years! Set final gap via dwell meter and made sure the base timing was right again as the final step in my "high tech" ignition tune up. READY FOR ANOTHER SEASON!
I had installed those points new about 5 years ago and I don't run this engine but maybe 10 hours per year, so it didn't seem likely the points would have been fouled up in such a short time, but they definitely were.
If you still run an old points distributor in your ride you should probably consider a fresh set of points every year, even if you don't drive the car very much. Seems that sitting unused can cause as much deterioration in them as high mileage can, especially if it gets stored outdoors.