Thinking easy coil question....
Thread Starter
Drifting
Joined: Dec 2015
Posts: 1,319
Likes: 221
From: Dalton, Ma
Thinking easy coil question....
My 1966 runs like crap, surgy, Skippy under load. Not a happy ride at all.
Throwing parts at it..wires, plugs, points. Haven't touched it yet. Figured swapping the coil might be an idea. Car has original style ignition w/ ballast resistor.. Seems like the coil was new 4-5 years ago..probably not the issue...
Here's the question. I have a known good hi performance 'red' coil. Can I just swap it in without regard to the fact it was for an application without a ballast resistor?
Throwing parts at it..wires, plugs, points. Haven't touched it yet. Figured swapping the coil might be an idea. Car has original style ignition w/ ballast resistor.. Seems like the coil was new 4-5 years ago..probably not the issue...
Here's the question. I have a known good hi performance 'red' coil. Can I just swap it in without regard to the fact it was for an application without a ballast resistor?
Thread Starter
Drifting
Joined: Dec 2015
Posts: 1,319
Likes: 221
From: Dalton, Ma
not the dwell, timing should be fine but it's on my list of things to check next but no spark knock and when its not Skippy or surgy, runs ***** out..
Absolutely could be the the carb but not sure what in the carb could cause this. I have access to a kit and I might swap out the power valve...
Absolutely could be the the carb but not sure what in the carb could cause this. I have access to a kit and I might swap out the power valve...
Le Mans Master
Joined: Feb 2012
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Likes: 2,880
From: Western Massachusetts
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If you can remove a coil you can borrow a DVM, set it to ohms and measure between the studs to find the primary resistance. But before you bother, why not approach a poor running car as most of us would. Basic stuff. Vacuum. Timing, compression check. Coils are not regular failures. A worn out set of points OR a malfunctioning Pertronix points substitute will cause all your symptoms. Its always faster, cheaper and more fun to find the problem while looking instead of firing the parts cannon at it, in which case you may fix it but you won't know why.
Dan
Dan
Le Mans Master
Joined: Nov 2015
Posts: 7,479
Likes: 2,650
From: Really Central IL Illinois
Before wholesale parts swap, do some troubleshooting:
1. remove the shielding if you have it, look for gray smoke marks on the wires and shielding indicating there has been a voltage leak to ground.
2. run the engine in a dark garage and look for fireworks from the plug wires, etc.
3. check the timing and dwell, set as needed.
4. pull the cap and look at the contacts in the cap and on the rotor. Look for cracks in the cap and gray smoke marks.
5. The condenser is hard to check without a meter, but it may be the problem and is cheap to replace. Visually check the points for pitting.
6.. inspect the ground wire going from the point plate to the vacuum advance canister mounting screw. You can visually inspect the wire and check it with a multimeter set on ohms.
7. check the vacuum canister with a vacuum pump or a hose applying suction and watch for it to stroke and hold when the vacuum achieves full stroke.
8. check the plug wires for a secure fit at the cap and also at the plugs.
9. pull the plugs and check the deposits and electrode gap. The electrode should be square at the end. Clean, set the gap, and reinstall if plugs read good and are not worn.
10. check the resistance on the primary and secondary sides of the coil with a multimeter set on ohms.
11. verify the choke is fully open when the engine is a NOT (normal operating temperature)
12. check the vacuum with a vacuum gauge and note the vacuum at idle and any fluctuation of the needle.
13. check for a vacuum leak at the carburetor base. Listen with a hose to your ear all around the base or use unlit propane torch and watch for rpm increase.
14. manually slowly close the choke plate or use a rag to cover the primaries to see if the idle increases or the engine dies out.
15. check the float levels, easy to do with a HOLLEY, not so much with a CARTER. Set as needed.
16. adjust the idle mixture screws for the highest vacuum reading and or rpm. They should be adjusted equally the same number of turns out.
There is a good chance running the engine while troubleshooting will foul the plugs a bit. Take the car for an aggressive 10 mile run where you can at least hit the speed limit.
Let the experts here know what your test results are. After replacing any defective parts identified during the testing. Also what engine, ignition in the distributor, and carburetor are.
References: The Chevrolet Chassis Service Manual - a must for these old cars.
The Holley technical site. https://www.holley.com/support/carburetor/ Lots of videos and troubleshooting help.
The Edelbrock technical site: https://www.edelbrock.com/installation-guides
Pictures of what you find will also help the members here help you.
Ron
1. remove the shielding if you have it, look for gray smoke marks on the wires and shielding indicating there has been a voltage leak to ground.
2. run the engine in a dark garage and look for fireworks from the plug wires, etc.
3. check the timing and dwell, set as needed.
4. pull the cap and look at the contacts in the cap and on the rotor. Look for cracks in the cap and gray smoke marks.
5. The condenser is hard to check without a meter, but it may be the problem and is cheap to replace. Visually check the points for pitting.
6.. inspect the ground wire going from the point plate to the vacuum advance canister mounting screw. You can visually inspect the wire and check it with a multimeter set on ohms.
7. check the vacuum canister with a vacuum pump or a hose applying suction and watch for it to stroke and hold when the vacuum achieves full stroke.
8. check the plug wires for a secure fit at the cap and also at the plugs.
9. pull the plugs and check the deposits and electrode gap. The electrode should be square at the end. Clean, set the gap, and reinstall if plugs read good and are not worn.
10. check the resistance on the primary and secondary sides of the coil with a multimeter set on ohms.
11. verify the choke is fully open when the engine is a NOT (normal operating temperature)
12. check the vacuum with a vacuum gauge and note the vacuum at idle and any fluctuation of the needle.
13. check for a vacuum leak at the carburetor base. Listen with a hose to your ear all around the base or use unlit propane torch and watch for rpm increase.
14. manually slowly close the choke plate or use a rag to cover the primaries to see if the idle increases or the engine dies out.
15. check the float levels, easy to do with a HOLLEY, not so much with a CARTER. Set as needed.
16. adjust the idle mixture screws for the highest vacuum reading and or rpm. They should be adjusted equally the same number of turns out.
There is a good chance running the engine while troubleshooting will foul the plugs a bit. Take the car for an aggressive 10 mile run where you can at least hit the speed limit.
Let the experts here know what your test results are. After replacing any defective parts identified during the testing. Also what engine, ignition in the distributor, and carburetor are.
References: The Chevrolet Chassis Service Manual - a must for these old cars.
The Holley technical site. https://www.holley.com/support/carburetor/ Lots of videos and troubleshooting help.
The Edelbrock technical site: https://www.edelbrock.com/installation-guides
Pictures of what you find will also help the members here help you.
Ron
Thread Starter
Drifting
Joined: Dec 2015
Posts: 1,319
Likes: 221
From: Dalton, Ma
Before wholesale parts swap, do some troubleshooting:
1. remove the shielding if you have it, look for gray smoke marks on the wires and shielding indicating there has been a voltage leak to ground. SHEILDS HAS BEEN OFF ALL ALONG
2. run the engine in a dark garage and look for fireworks from the plug wires, etc. I CAN DO THAT..
3. check the timing and dwell, set as needed. NEW POINT TODAY DWELL SET
4. pull the cap and look at the contacts in the cap and on the rotor. Look for cracks in the cap and gray smoke marks. ALL GOOD
5. The condenser is hard to check without a meter, but it may be the problem and is cheap to replace. Visually check the points for pitting. NEW POINTS TODAY
6.. inspect the ground wire going from the point plate to the vacuum advance canister mounting screw. You can visually inspect the wire and check it with a multimeter set on ohms.
7. check the vacuum canister with a vacuum pump or a hose applying suction and watch for it to stroke and hold when the vacuum achieves full stroke. WORKS PERFECT issue doesn't change with cannister vacuum hooked up or not
8. check the plug wires for a secure fit at the cap and also at the plugs. NEW WIRES AND PLUGS, NO ISSUE BUT I CAN TRIPLE CHECK
9. pull the plugs and check the deposits and electrode gap. The electrode should be square at the end. Clean, set the gap, and reinstall if plugs read good and are not worn. LIKE I SAID>>>NEW
10. check the resistance on the primary and secondary sides of the coil with a multimeter set on ohms. WILL CHECK TOMORROW
11. verify the choke is fully open when the engine is a NOT (normal operating temperature) CHOKE IS ELECTRIC AND WORKS FINE HOT AND COLD
12. check the vacuum with a vacuum gauge and note the vacuum at idle and any fluctuation of the needle. ON THE LIST BUT WILL HAVE TO BORROW A GAUGE
13. check for a vacuum leak at the carburetor base. Listen with a hose to your ear all around the base or use unlit propane torch and watch for rpm increase. I CAN DO THAT
14. manually slowly close the choke plate or use a rag to cover the primaries to see if the idle increases or the engine dies out. DONE, DOESN'T LIKE TO BE CLOSED
15. check the float levels, easy to do with a HOLLEY, not so much with a CARTER. Set as needed. NEW NEEDLE AND SEAT IN THE FRONT ,BOTH ADJUSTED PROPERLY LAST WEEK
16. adjust the idle mixture screws for the highest vacuum reading and or rpm. They should be adjusted equally the same number of turns out. DONE 1 1/4 TURNS OUT
There is a good chance running the engine while troubleshooting will foul the plugs a bit. Take the car for an aggressive 10 mile run where you can at least hit the speed limit.
Let the experts here know what your test results are. After replacing any defective parts identified during the testing. Also what engine, ignition in the distributor, and carburetor are.
References: The Chevrolet Chassis Service Manual - a must for these old cars.
The Holley technical site. https://www.holley.com/support/carburetor/ Lots of videos and troubleshooting help.
The Edelbrock technical site: https://www.edelbrock.com/installation-guides
Pictures of what you find will also help the members here help you.
Ron
1. remove the shielding if you have it, look for gray smoke marks on the wires and shielding indicating there has been a voltage leak to ground. SHEILDS HAS BEEN OFF ALL ALONG
2. run the engine in a dark garage and look for fireworks from the plug wires, etc. I CAN DO THAT..
3. check the timing and dwell, set as needed. NEW POINT TODAY DWELL SET
4. pull the cap and look at the contacts in the cap and on the rotor. Look for cracks in the cap and gray smoke marks. ALL GOOD
5. The condenser is hard to check without a meter, but it may be the problem and is cheap to replace. Visually check the points for pitting. NEW POINTS TODAY
6.. inspect the ground wire going from the point plate to the vacuum advance canister mounting screw. You can visually inspect the wire and check it with a multimeter set on ohms.
7. check the vacuum canister with a vacuum pump or a hose applying suction and watch for it to stroke and hold when the vacuum achieves full stroke. WORKS PERFECT issue doesn't change with cannister vacuum hooked up or not
8. check the plug wires for a secure fit at the cap and also at the plugs. NEW WIRES AND PLUGS, NO ISSUE BUT I CAN TRIPLE CHECK
9. pull the plugs and check the deposits and electrode gap. The electrode should be square at the end. Clean, set the gap, and reinstall if plugs read good and are not worn. LIKE I SAID>>>NEW
10. check the resistance on the primary and secondary sides of the coil with a multimeter set on ohms. WILL CHECK TOMORROW
11. verify the choke is fully open when the engine is a NOT (normal operating temperature) CHOKE IS ELECTRIC AND WORKS FINE HOT AND COLD
12. check the vacuum with a vacuum gauge and note the vacuum at idle and any fluctuation of the needle. ON THE LIST BUT WILL HAVE TO BORROW A GAUGE
13. check for a vacuum leak at the carburetor base. Listen with a hose to your ear all around the base or use unlit propane torch and watch for rpm increase. I CAN DO THAT
14. manually slowly close the choke plate or use a rag to cover the primaries to see if the idle increases or the engine dies out. DONE, DOESN'T LIKE TO BE CLOSED
15. check the float levels, easy to do with a HOLLEY, not so much with a CARTER. Set as needed. NEW NEEDLE AND SEAT IN THE FRONT ,BOTH ADJUSTED PROPERLY LAST WEEK
16. adjust the idle mixture screws for the highest vacuum reading and or rpm. They should be adjusted equally the same number of turns out. DONE 1 1/4 TURNS OUT
There is a good chance running the engine while troubleshooting will foul the plugs a bit. Take the car for an aggressive 10 mile run where you can at least hit the speed limit.
Let the experts here know what your test results are. After replacing any defective parts identified during the testing. Also what engine, ignition in the distributor, and carburetor are.
References: The Chevrolet Chassis Service Manual - a must for these old cars.
The Holley technical site. https://www.holley.com/support/carburetor/ Lots of videos and troubleshooting help.
The Edelbrock technical site: https://www.edelbrock.com/installation-guides
Pictures of what you find will also help the members here help you.
Ron
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