Problem Setting Dwell Angle
Thread Starter
Pro
Joined: Jan 2001
Posts: 511
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From: Timnath, CO
Problem Setting Dwell Angle
My car was running well, but I decided it was time for annual check on dwell and timing. Was surprised to find dwell angle was about 20 degrees. I tried to set it back to spec of 28-32, but car would start to surge and I had to back off. Car runs very poorly now.
I changed the points to a new heavy duty set in case that was the problem (I did not change the condenser). Getting the same problem - have to leave the dwell in low 20's for the car to run, and it drives poorly.
A couple of other observations. I had the car professionally tuned a few years ago. I checked the dwell about nine months later and it was about 20 degrees (why?). I was able to adjust it to spec then and car ran well. Why did it change back to 20 degrees over the next year?
When I was poking around to get the allen wrench in the points adjuster I saw a spark. don't know if I briefly shorted something out.
When I drive the car now, It hesitates from a stop which it did not used to do. It also feels like it is hesitating while cruising at low speeds.
Any ideas on this?
Thanks
I changed the points to a new heavy duty set in case that was the problem (I did not change the condenser). Getting the same problem - have to leave the dwell in low 20's for the car to run, and it drives poorly.
A couple of other observations. I had the car professionally tuned a few years ago. I checked the dwell about nine months later and it was about 20 degrees (why?). I was able to adjust it to spec then and car ran well. Why did it change back to 20 degrees over the next year?
When I was poking around to get the allen wrench in the points adjuster I saw a spark. don't know if I briefly shorted something out.
When I drive the car now, It hesitates from a stop which it did not used to do. It also feels like it is hesitating while cruising at low speeds.
Any ideas on this?
Thanks
Thread Starter
Pro
Joined: Jan 2001
Posts: 511
Likes: 66
From: Timnath, CO
I may feel stupid but relieved this was an easy fix. Thanks for your help.
Thread Starter
Pro
Joined: Jan 2001
Posts: 511
Likes: 66
From: Timnath, CO
Melting Slicks
Joined: Apr 2009
Posts: 2,632
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From: Great Plains Iowa
My old Marquette dwell meter has to be "zeroed" first to compensate for reduced battery voltage (uses a 9-volt battery). I suggest upgrading your ignition to a Pertronix to get rid of the points because points slowly destroy the upper shaft bushing because of the side load they impart on it. Or better yet go with an HEI.
Thread Starter
Pro
Joined: Jan 2001
Posts: 511
Likes: 66
From: Timnath, CO
My old Marquette dwell meter has to be "zeroed" first to compensate for reduced battery voltage (uses a 9-volt battery). I suggest upgrading your ignition to a Pertronix to get rid of the points because points slowly destroy the upper shaft bushing because of the side load they impart on it. Or better yet go with an HEI.
I only drive less than 1,000 miles a year so plan to stick with the points for now.
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Yep...ck timing.
If you increase gap....you decrease the dwell....which increases the timing.
In your case...the rubbing block on points has worn...so you decreased the gap....increased the dwell...and decreased the timing.
Set dwell and then verify the timing.
A good set of points will last a long time. I used Accel's for years on the street with no issues at 7500 RPM and 800+ HP.
JIM
If you increase gap....you decrease the dwell....which increases the timing.
In your case...the rubbing block on points has worn...so you decreased the gap....increased the dwell...and decreased the timing.
Set dwell and then verify the timing.
A good set of points will last a long time. I used Accel's for years on the street with no issues at 7500 RPM and 800+ HP.
JIM
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