My '79 Log Thread

[infernosg]

Overhauled the distributor: new points, rotor, cap, and 3 of the 4 condensers (I mis-read the Parts List), and replaced the spark plug wires. Got the timing set, which was a bit of a chore. The leading timing was easy but I can't seem to get a good signal for the trailing timing. I set it as best I could then went about adjusting the idle fuel mixture and idle speed per some guidelines I found online. The car seems to be running marginally better. Every now and then the tachometer "bounces" a couple hundred RPM at idle/low engine load. I opened the points gap up closer to .020 in. and that seems to have helped but it still happens. Crappy aftermarket points? Who knows.

Snapped a couple pictures of the dirty interior:





Once I finish the maintenance I'll go back and detail the car. Trying to get it ready for the Fall car show season.

[Pete_89T2]

Originally Posted by infernosg

Overhauled the distributor: new points, rotor, cap, and 3 of the 4 condensers (I mis-read the Parts List), and replaced the spark plug wires. Got the timing set, which was a bit of a chore. The leading timing was easy but I can't seem to get a good signal for the trailing timing. I set it as best I could then went about adjusting the idle fuel mixture and idle speed per some guidelines I found online. The car seems to be running marginally better. Every now and then the tachometer "bounces" a couple hundred RPM at idle/low engine load. I opened the points gap up closer to .020 in. and that seems to have helped but it still happens. Crappy aftermarket points? Who knows.

Once I finish the maintenance I'll go back and detail the car. Trying to get it ready for the Fall car show season.

Using an inductive clamp-on timing light? I had a similar problem in the '80's when checking/setting trailing timing on my '85 GSL-SE. Figured out that the timing light was sporadically triggering off the leading signal. Given the proximity of all the wires, the radiated EMI off the leading wires can easily trigger a too sensitive timing light, even if the inductive pick up is clamped on to the trailing wire.

If this is what is going on, you can try moving the pickup/wires around to try to increase the distance between the pick-up and any leading wires. This helped me, but I didn't have consistent luck with it on my GSL-SE, so being an EE, I modified my cheapo timing light to adjust the pickup's sensitivity.

What I did was put a 5K ohm variable resistor (linear taper) in series with the pick up lead. To use it on the trailing wire, start with the variable resistor set at 0 resistance (max sensitivity), and dial it back until the timing light stops flashing completely. Then SLOWLY dial it back up (add resistance) until the light just begins to flash again. If you didn't overshoot, you should now be seeing consistent flashes only on the trailing signal.

[infernosg]

Originally Posted by Pete_89T2

Using an inductive clamp-on timing light? I had a similar problem in the '80's when checking/setting trailing timing on my '85 GSL-SE. Figured out that the timing light was sporadically triggering off the leading signal. Given the proximity of all the wires, the radiated EMI off the leading wires can easily trigger a too sensitive timing light, even if the inductive pick up is clamped on to the trailing wire.

If this is what is going on, you can try moving the pickup/wires around to try to increase the distance between the pick-up and any leading wires. This helped me, but I didn't have consistent luck with it on my GSL-SE, so being an EE, I modified my cheapo timing light to adjust the pickup's sensitivity.

What I did was put a 5K ohm variable resistor (linear taper) in series with the pick up lead. To use it on the trailing wire, start with the variable resistor set at 0 resistance (max sensitivity), and dial it back until the timing light stops flashing completely. Then SLOWLY dial it back up (add resistance) until the light just begins to flash again. If you didn't overshoot, you should now be seeing consistent flashes only on the trailing signal.

Yeah, I'm using a cheap Actron inductive timing light. I figured I was likely picking up a signal off the leading spark plug. I'm also near the end of the adjust-ability to advance the trailing timing. When I get a chance to work on the car again I'll move the pick-up around some more and try again. Regardless, the car seems to be running well-enough. Better than it was when I first got it.