Dennis Detweiler Posted August 21, 2020 Report Posted August 21, 2020 I haven't touched the dwell and timing on my 39 Plymouth since I purchased the car 3 years ago. I've been working on other upgrades to the car during that time. It was idling very rough, plugs sooty, stalling at idle. The vacuum meter showed vibrating needle as if it had bad valve guides. The timing marks on the crank pulley were covered in rust, likely for years. I checked the dwell and it was 50+. After finding the timing marks on the pulley the timing was 3 inches on the negative side of the marks. Adjusting the carb made no difference. I set the dwell to 39 degrees, timing at +2 and adjust the carb using the vacuum guage and set the idle adjustment to proper speed. Now it runs and idles like a new engine and the vacuum guage shows that the engine is in good condition. I only mention this in case someone finds their recent purchase idling as if it's valve guides were worn. A tuneup can solve this problem. 5 Quote
PT81PlymouthPickup Posted August 23, 2020 Report Posted August 23, 2020 On 8/20/2020 at 8:26 PM, Dennis Detweiler said: I haven't touched the dwell and timing on my 39 Plymouth since I purchased the car 3 years ago. I've been working on other upgrades to the car during that time. It was idling very rough, plugs sooty, stalling at idle. The vacuum meter showed vibrating needle as if it had bad valve guides. The timing marks on the crank pulley were covered in rust, likely for years. I checked the dwell and it was 50+. After finding the timing marks on the pulley the timing was 3 inches on the negative side of the marks. Adjusting the carb made no difference. I set the dwell to 39 degrees, timing at +2 and adjust the carb using the vacuum guage and set the idle adjustment to proper speed. Now it runs and idles like a new engine and the vacuum guage shows that the engine is in good condition. I only mention this in case someone finds their recent purchase idling as if it's valve guides were worn. A tuneup can solve this problem. Dennis, Does your distributor have a vacuum advance and did you happen to check how much it advanced when you opened the throttle? My 39 Plymouth truck with vacuum advance connected, advances to about 22 degrees before TDC. Seems like too much to me? I'm hoping to make a comparison to see if this is normal? Quote
Dodgeb4ya Posted August 23, 2020 Report Posted August 23, 2020 Regular maintenance is a good thing. Glad it's running like new again! Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.