Rough Idle (170)
- Thread starter Junior64
- Start date
If you want to check your spark control valve, you can do that with a vacuum gauge. If you connect the gauge to the distributor vacuum line you should see little to no vacuum at idle increasing gradually to maybe 5 inches at 2000 RPM and a bit higher at WOT.
It's not the numbers that are important, as they varied with the Loadomatic and carb setup. What's important is that the vacuum starts out low or none and increases gradually to wide open throttle.
If you want to get deeper into it, you can take an adjustable timing light to the car and with the vacuum advance hooked up you can read the number of degrees advanced at different RPM's. You'll see your basic 10 degrees or so at idle, increasing to maybe 20 - 25 degrees as you throttle it up.
With no pinging and the timing set as you mention, it sounds like your advance and spark valve is doing what it should, which is no little accomplishment for these setups.
It's not the numbers that are important, as they varied with the Loadomatic and carb setup. What's important is that the vacuum starts out low or none and increases gradually to wide open throttle.
If you want to get deeper into it, you can take an adjustable timing light to the car and with the vacuum advance hooked up you can read the number of degrees advanced at different RPM's. You'll see your basic 10 degrees or so at idle, increasing to maybe 20 - 25 degrees as you throttle it up.
With no pinging and the timing set as you mention, it sounds like your advance and spark valve is doing what it should, which is no little accomplishment for these setups.
Junior64
Well-known member
The vacuum works as you described. Little to none at idle and a gradual increase. I don't have a gauge to hook up, I just used my calibrated finger 8) When I get back into town, I'm gonna narrow the gaps on the plugs and get that modulator valve replaced. Will ATF leak out after I remove it?
