Re: 1968 1000ss running problem
Usually that is a symptom of a bad distributor trigger assembly.
But, before trashing that very expensive part, here's something to check:
On the switchbox (ign module), there are a series of connections on the port side coming from the distributor. You don't want to mess with those yet!
On the Starboard side, you'll see more connections. Find a red wire going to one of the posts on the Port side of the switchbox, and check for voltage with the ign "OFF" and also "ON". You should find that the red wire is "hot" all the time.
On the same side of the switchbox as the red wire, you'll find a white wire.
When the ign is "ON", that white wire must be "hot". You can connect your meter or test lite to the white terminal and crank over the engine, if you find power is present in the "START" position but not in the "ON" position, the problem's in your ign switch as you're suspecting.
If you don't find that to be the problem, it's very likely your trigger. Here's a Merc CDI ign test which should help you figure out the problem (info courtesy of Clams Canino):
"MERCURY BATTERY-POWERED CDI TEST FOR DISTRIBUTOR MODELS
This test is for the 332-2986 switchbox used from 1967-1978 on all the inlines.
This test assumes your coil is good (problems with CDI coils are rare).
DISCONNECT BATTERY
1. Turn off ignition;
2. Disconnect all 3 distributor wires on the Port side of the switchbox (and the ?mercury switch? if present);
3. Remove the HV lead from the ign coil to the center of the dist. cap (remember it unplugs from the coil and unscrews from the cap);
4. Reconnect the HV lead to the COIL only;
5. Position the free end of the HV lead approx. 3/8" from ground (block, shrouds etc), and find a way to hold it there;
6. Jumper the brown and white terminals on the dist. side of the switchbox to each other.
RECONNECT BATTERY
7. Check that you have +12V at the red terminal (even with the ign off);
8. Turn on ignition and verify +12V at the white terminal (same side as the red terminal);
9. Ground the black terminal on the distributor side of the switchbox - this should cause a spark each time you touch ground.
If you get spark with the distributor bypassed, and it won't fire with the distributor connected, the trigger is bad and the entire distributor housing assy must be replaced.
If you get no spark using the test, the switchbox is probably bad. In that case, be sure to check for correct power on the switchbox, check all connections, and check the coil's resistance to make sure it's OK.
But for Inline Sixes from approx '68-'79 with belt-driven distributor (3 & 4-cyl's too except for those with Lightning Energizer ign), the above test will confirm a bad trigger. "
Hopefully it's just the ign switch, but this should help you figure it out.......ed
p.s. one other thing you can try before tearing things apart, is to connect a jumper (alligator clips will do) from the red (always "hot") wire to the white wire on the SAME side of the switchbox.
With the white wire jumpered to red, you'll have spark all the time, regardless of position of ign switch. Then see if it'll start and run. If it does, the ign switch is definitely bad. If not, suspect trigger assy. Note: you'll have to pull the jumper to kill the engine!
HTH & G'luck.......ed
