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| Joined: | 05-01-2005 |
| Location: | Minneapolis, Minnesota USA |
| Posts: | 573 |
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Hi Rory I thought of that, so I checked it. With #1 at TDC and the cam sprockets lining up, the rotor is pointing to the correct contact within the distributor. Thanks
Colin,
This is long. Sorry if I lose you with the length.
With the crank at TDC and the cam pulley timing dots properly aligned, #1 cyl is at TDC. Good. With the engine in that position...
Normally the ignition fires as the rotor arm is just overlapping the terminal on the distributor... not on-center with it. That's to maximize the rotor/terminal proximity duration as the rotor sweeps by so the spark can jump over a time period at high rpm (the spark isn't instantaneous). If you have the rotor aligned straight-on with the terminal at TDC, then the ignition timing is probably actually after TDC. You want 8 - 14 degrees before TDC.
With #1 at TDC, all you should be looking for is which terminal (+/_) is the rotor pointing toward (not timing). That's the #1 terminal, so make sure the #1 spark plug wire attaches there. Then install the rest of the wires in 1-3-4-2 order, counter-clockwise around the distributor as you look at the top of the cap. "IF" #1 is pointing straight up, #3 will point at the engine block, #4 straight down and #2 at the oil filter.
Now turn the crank through one more revolution, stopping when the pulley hash mark aligns with whatever static timing you want, stop there. You don't have to go around two revolutions and back to approaching #1 TDC. After you have determined the #1 terminal and installed the wires properly, it's enough to just go around once. The distributor will fire each time the crank approaches TDC. For "ignition" timing purposes, it doesn't matter if it's #1 that's firing, or #4. They'll both fire with the same advance.
Connect a continuity light between ground and either of the 12v terminals on the ignition coil. With the ignition on, the test light will be off or dim when the coil is charging (OEM breaker points would be closed). The light will turn on or become bright when the points open to fire the coil. Off-dim and on-bright depend upon the current rating of the test lamp and how much current it is drawing. "Off" is just a special case of "dim"... etc.
With the crank's timing hashmark set to desired static timing, test light connected and the ignition "on"... Loosen the distributor clamp so you can rotate the body (apply inward hand pressure to the distributor to hold it into the housing against the spring pressure "before" loosening the clamp). Rotate the distributor back and forth a bit to find where it switches from off/dim to on/bright.
If you have followed instructions, started at #1 TDC, and went to your static timing point (8 BTDC ?), then you will find the on-off point a little clockwise from your starting point. "Clockwise" as you look at the open end of the distributor body/ top of the cap... ie, turn toward the oil filter. Find the on-off point, then rotate back and forth a few times watching the light go on-off to get a feel for where the on-off point is.
From the on-off point, rotate the distributor body counter-clockwise toward the engine block until the light goes off... then a bit more. Then reverse, and rotate the distributor body clock-wise back toward the oil filter until the light "just" comes on or gets bright. Stop immediately without over-shooting. If you miss it, back up and try again. When you're comfortable that you nailed it to your satisfaction, tighten the distributor clamp. Do not release the inward hand pressure upon the distributor until after the clamp is tight... or you'll be re-installing the distributor.
Now the ignition is static timed. Turn the Ignition off as soon as you're done (important... don't leave it on). Disconnect continuity test light.
If the light doesn't change at all when you rotate the distributor body, then something is wrong in the distributor/coil circuit. If there's voltage at the coil (+) and (-) terminals, then follow the white wire from the coil's (-) terminal to the distributor and check for voltage there. If no voltage, the wire is bad, fix it. If there is voltage at the distributor end, but the test light doesn't change (off or dim to on or bright), then there's a problem with the Pertronix unit or it's installation.
Early PERTRONIX FRAILTY: When the ignition is "On", current may or may not be flowing through the coil depending upon the position of the distributor. If the distributor is in one of the four positions where the coil/spark has just fired, then the 12v to the coil-charging current is off and not flowing through the Pertronix amp.
However, at all other times, coil-charging current is flowing through the Pertronix amp full time whenever the ignition is "On" and the distributor isn't turning. That puts the amp in a 100% duty cycle condition it was not designed for... originally. In that case, early Mk 1 Pertronix amps will overheat and fry fairly quickly... a few minutes. The damage is permanent and the cure is a new unit. When working on the engine/ ignition, do not turn the ignition "On" and leave it on. Switch "On", do your task, switch "Off".
Later Mk II Pertronix units have a heavier duty amp that can withstand prolonged current... but it's still best not to push your luck.
Also, both Pertronix units are polarity sensitive and intolerant of reversed bias. Do not apply reverse polarity for even an instant or you'll be replacing it.
I guess what I'm saying is that your Pertronix unit may have died even though you "didn't do anything to it"... intentionally.
SPARK CHECK: Voltage gets to the coil via two paths. One wire goes to the ballast resistor which drops nominal system voltage down to 7-8 volts. That's for normal running. A second wire coming from the terminal on the starter solenoid, bypasses the resistor and feeds 12v directly to the coil during starting. 12v for starting, 7-8v for normal running after the starter is released. Check that both circuits are working.
After confirming that the coil is getting voltage, trigger it manually and watch for a spark. To trigger the coil, remove the wires from both the (+) and (-) coil terminals. Make a jumper wire to connect the (-) terminal directly to ground. Make a second jumper and connect it to the (+) terminal and have it long enough to reach the battery'e (+) terminal.
Pull the high tension coil wire off the distributor cap and make sure the other end is firmly seated in the top of the coil. Pull the boot back on the free end to expose the terminal, then hold it near a good ground... like the engine block (not the carbs/ intake manifold). Grip the wire well back from the terminal to avoid a shock.
Hold the coil's high tension wire near a good ground but not touching (gotta see the spark jump). Touch the free end of the (+) jumper wire to the battery's (+) terminal briefly, then lift if off. Everytime the batterry connection is broken, the coil will fire and you should see a spark jump from the coil HT wire to the ground point.
If a spark jumps, the coil and high tension lead are both good. If no spark, then one or both are bad. Replace the coil HT lead with a known good one and repeat the test. Still no spark?... the coil is bad. Replace it.
With a confirmed good coil and HT wire, a spark will jump every time you lift the jumper wire off the battery (+) terminal. When you get to that situation, put all the wires back in their proper places on the coil.
Now, test for spark using the Pertronix to trigger the coil. Coil 12v wires installed, coil HT lead still disconnected and held near a good round, transmission in neutral, key the starter to turn the engine over. If no spark occurs, then the problem is either in the Pertronix unit, or in the small, white 12v wire from the coil's (-) terminal to the distributor/ Pertronix unit.
Test for voltage at the Pertronix end of the wire. If you have primary voltage there, then the wire/ circuit is good and the problem is in the Pertronix or it's installation.
No jab intended... but are you familiar with starting a carb'd engine? In this day of fuel injected engines, that's a fair question. With fuel injection you aren't supposed to do anything other than key the starter. With carbs you need to be an active participant. You won't have much success if you don't do your part.
Good luck
Tim Engel