Rough idle - need mechanic name or a mentor in Charlotte

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Hscott

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I have been fighting a rough idle on my 302 for some time and need to find someone locally to help. Any members in the Charlotte area that might be able to recommend a solid local mechanic? Mentors welcome too. Thank You! :)
 
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I have been fighting a rough idle on my 302 for some time and need to find someone locally to help. Any members in the Charlotte area that might be able to recommend a solid local mechanic? Mentors welcome too. Thank You! :)
I can guide you how to repair this problem
 

Hscott

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I can guide you how to repair this problem
I can guide you how to repair this problem
Many thanks. I have limited experience but am a quick study and have many but not all diagnostic tools. I appreciate your help! What details would be most helpful for you to assess the problem. Should we do this offline...email, etc. Quick info:. Car is totally stock. A 1972 302. A/T. Was originally a California vehicle with environmental add-ons. The current set-up is using ported vacuum, only. The manifold vacuum is not being used and was capped except for the p/s assist and transmission. I attempted to replace the manifold vaccum lines using routing maps but couldn't get the car to run correctly and removed them. So, at this point I am using ported vacuum, only. Plugs, wires and the carburetor were all replaced. An electronic ignition was swapped for the points. I timed the motor recently and believe it is set right. The car starts easily and idles well in park but when in gear and stopped the car has a consistent but mild shake. Please let me know what additional info would be helpful and again thank you! I appreciate your time and assistance.
 
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Hmmm. My first guess would be a broken plug wire. You said they are new wires, but you may verify you do not have a miss there.

Put a vacuum gage on it and see if you are getting smooth and consistent vacuum. If not, do a compression check.

Kcmash
 

Hscott

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Hmmm. My first guess would be a broken plug wire. You said they are new wires, but you may verify you do not have a miss there.

Put a vacuum gage on it and see if you are getting smooth and consistent vacuum. If not, do a compression check.

Kcmash

I will need to pick up a vacuum gauge. I will also re-inspect the wires. Thanks very much for the response.
 
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At what RPM is the engine idling and at what RPM is it once it is in gear? The timing could be a tad retarded, and maybe the idle RPM a tad low and that would give you a mild "shake" in gear. When you went to electronic ignition what did you use? Where is the timing set at idle? Do you know what the centrifugal timing in the distributor is, how many degrees the distributor advances?
 
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Many thanks. I have limited experience but am a quick study and have many but not all diagnostic tools. I appreciate your help! What details would be most helpful for you to assess the problem. Should we do this offline...email, etc. Quick info:. Car is totally stock. A 1972 302. A/T. Was originally a California vehicle with environmental add-ons. The current set-up is using ported vacuum, only. The manifold vacuum is not being used and was capped except for the p/s assist and transmission. I attempted to replace the manifold vaccum lines using routing maps but couldn't get the car to run correctly and removed them. So, at this point I am using ported vacuum, only. Plugs, wires and the carburetor were all replaced. An electronic ignition was swapped for the points. I timed the motor recently and believe it is set right. The car starts easily and idles well in park but when in gear and stopped the car has a consistent but mild shake. Please let me know what additional info would be helpful and again thank you! I appreciate your time and assistance.
Sorry took me so long to respond. My email is [email protected] if you still need assistance Rick
 

Hscott

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At what RPM is the engine idling and at what RPM is it once it is in gear? The timing could be a tad retarded, and maybe the idle RPM a tad low and that would give you a mild "shake" in gear. When you went to electronic ignition what did you use? Where is the timing set at idle? Do you know what the centrifugal timing in the distributor is, how many degrees the distributor advances?
Hi. The rpm at idle in gear is 6k. Drops to under 5k when placed into drive. Timing is at 6btc. Tested with distributor vacuum disconnected.
 

Sheriff41

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Might want to advance your timing to 10-12° and start there. Also, your idle RPM is a little low, IMHO. See what it idles at after advancing the timing. 700-750 in park (550-600 in drive) is my target.
 
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Hscott

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Thank you. I will do so. I just received my vacuum gauge and it read that timing was just off the green/good zone. Although, when I adjusted the distributor to get it solidly.in the green zone it was shaking pretty.bad in the engine bay. I moved it back to where it was right on the line between green and red. I need to put the timing light back on and see what the timing is set after the adjustment.with the vacuum gauge. Question ...when I have gauge plugged into manifold vacuum should the ported line from the carb to the vacuum advance be connected.or disconnected? Many thanks for your input above.
 
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