Can someone help me set the dwell on my 1969 Caddy Deville 472 big block. I have an older model Hanson/Hawk dwell meter with a black and red lead. Where do I connect the leads to . Do I turn the engine over to test the dwell, or do I crank the car?
The car must be running the neg to ground the positive to the point lead from the distribtor to the coil... I hope this helps you..
The red wire goes to the terminal of the coil that leads to the distributor, and the black wire goes to any ground.
The dwell spec you can look up, but it's probably 28 to 32 degrees, so 30 is optimum. Car needs to be running.
If your cap has the slideup window, you can see that the points can be adjusted with an Allen wrench. Most auto parts stores will carry a tool for this that looks like a long screwdriver with a semi-flexible allen key on the end.
I guess I am getting old because this is something we did on our cars almost monthly when we were kids.
Set the dwell, then set the timing with a timing light. Disconnect the vaccum to the distributor, and plug the hose.
Good luck,
Brian
Quote from: Ohio57-62Sedan on January 08, 2009, 03:34:44 PM
The car must be running the neg to ground the positive to the point lead from the distribtor to the coil... I hope this helps you..
Thank you for your time.
Quote from: 76eldo on January 08, 2009, 04:02:02 PM
The red wire goes to the terminal of the coil that leads to the distributor, and the black wire goes to any ground.
The dwell spec you can look up, but it's probably 28 to 32 degrees, so 30 is optimum. Car needs to be running.
If your cap has the slideup window, you can see that the points can be adjusted with an Allen wrench. Most auto parts stores will carry a tool for this that looks like a long screwdriver with a semi-flexible allen key on the end.
I guess I am getting old because this is something we did on our cars almost monthly when we were kids.
Set the dwell, then set the timing with a timing light. Disconnect the vaccum to the distributor, and plug the hose.
Good luck,
Brian
Brian,
Thanks for your help. I am 27 years old and this is my first older model Cad. I appreciate your time.
To use a dwell meter for adjusting contact points, connect the red lead of the dwell meter to the distributor side of the ignition coil (wire going to the contact points). Connect the black lead to ground.
If the distributor cap has an adjustment window, the points should be set with the engine running. With the meter controls set properly, adjust the points through the window of the distributor cap using a Allen wrench or a special screwdriver. Turn the point adjustment screw until the dwell meter reads within manufacturer’s specification.
However, if the distributor cap does not have an adjustment window, remove the distributor cap and ground the ignition coil wire. Then crank the engine; this action will simulate engine operation and allow point adjustment with the dwell meter.
Dwell specifications vary with the number of cylinders. An eight-cylinder engine requires 30 degrees of dwell. An engine with few cylinders requires more dwell time. Always consult the manufacturer’s service manual for exact dwell values.
Dwell should remain constant as engine speed increases or decreases. However, if the distributor is worn, you can have a change in the dwell meter reading. This is known as DWELL VARIATION. If dwell varies more than 3 degrees, the distributor should either be replaced or rebuilt. Also, a change in the point gap or dwell will change ignition timing. For this reason, the points should always be adjusted before ignition timing.
For more, go to this site to learn how to set your points, cap, rotor, plugs, etc.
http://www.tpub.com/content/construction/14273/css/14273_70.htm
Quote from: ottoskorzeny on January 08, 2009, 05:46:53 PM
To use a dwell meter for adjusting contact points, connect the red lead of the dwell meter to the distributor side of the ignition coil (wire going to the contact points). Connect the black lead to ground.
If the distributor cap has an adjustment window, the points should be set with the engine running. With the meter controls set properly, adjust the points through the window of the distributor cap using a Allen wrench or a special screwdriver. Turn the point adjustment screw until the dwell meter reads within manufacturer’s specification.
However, if the distributor cap does not have an adjustment window, remove the distributor cap and ground the ignition coil wire. Then crank the engine; this action will simulate engine operation and allow point adjustment with the dwell meter.
Dwell specifications vary with the number of cylinders. An eight-cylinder engine requires 30 degrees of dwell. An engine with few cylinders requires more dwell time. Always consult the manufacturer’s service manual for exact dwell values.
Dwell should remain constant as engine speed increases or decreases. However, if the distributor is worn, you can have a change in the dwell meter reading. This is known as DWELL VARIATION. If dwell varies more than 3 degrees, the distributor should either be replaced or rebuilt. Also, a change in the point gap or dwell will change ignition timing. For this reason, the points should always be adjusted before ignition timing.
For more, go to this site to learn how to set your points, cap, rotor, plugs, etc.
http://www.tpub.com/content/construction/14273/css/14273_70.htm
Very helpful information. Today I set the dwell to 30 and set timing with a timing light. The engine is still running a little rough. It also does not shut off correctly. When I turn the ignition switch off the car makes a horrible noise, and it almost sounds like the engine reverses. Air and gas are blown back through the carb. Any suggestions?
now you need to set the timing
Your car is dieseling. I'll assume you've already installed new plugs, wires, cap, rotor, etc. and have a full tank of new, clean gas of the proper octane rating for your car.
You now need to set the timing according to specs. This includes all necessary adjustments to a properly functioning carburetor.
First of all, it's nice to see a younger person taking an interest in a 69 Cadillac. It sounds like you already have begun teaching yourself how to maintain the car.
You will find that we are willing to help. That 472 engine is a strong motor, and when tuned correctly should run very well.
If the timing is too far advanced, the car will ping, and also suffer from pre-ignition, which is the engine continuing to sputter and run on after you turn off the key. For a short term fix, keep the car in "drive" when you turn it off while you are looking for the cause. Don't let it cough and carry on for any longer than you need to.
Now you need to figure out what is going on.
In setting the "base" timing you need to remove the vacuum from the distributor. You can plug up the vacuum line with a golf tee, or small bolt.
Set the timing to spec. Also observe if the mechanical advance is working. When you rev the engine, the timing mark should change. Maybe yours is stuck in the advanced position.
Another likely source is excessive carbon on the tops of the pistons. I used to use GM Top Engine Cleaner, which is poured through the carb. I don't know if this stuff is still available, but you can probably find something similar in a good auto parts store.
What I used to do with this magical stuff is dribble about half of the can through the carb, raising the throttle to keep it from stalling. The taking the 2nd half of the can, dump it in to the carb, choking the engine out. Turn off the key, and wait 15 to 20 minutes. Then start the car. You will see horrible smoke coming out of the exhaust, and what you need to do is now take the car out for a nice run, about 20 minutes or so, and beat on it a little. You will have blown out a lot of carbon and old varnish, and the car will run much better.
Then put a little dab of grease on the back of the gas pedal where it rubs on the metal lever part of the throttle linkage. At this point, it will feel like you took 40K miles off of the car, providing everything else is tuned properly.
Let us know how you make out.
Dieseling can also be caused by something as simple as the idle set too fast, once the timing is properly set (you really SHOULD have a Shop Manual for this car) make sure the idle is also set to specs. Actually the idle should be set slow enough so that the mechanical advance is not coming into play in the first place when adjusting the timing. If I remember correctly the final idle is set by adjusting the anti-dieseling solenoid, not the carburetor itself (after the carburetor is adjusted correctly).
You really SHOULD have the Shop Manual for this car! Check for them in eBay or from outfits such as Crank 'en Hope and many other sources that sell original or repros of shop manuals.
Geoff is correct about the idle.
All of the other stuff won't hurt a bit.
Brian
Quote from: Geoff Newcombe #4719 on January 09, 2009, 09:20:28 AM
Dieseling can also be caused by something as simple as the idle set too fast, once the timing is properly set (you really SHOULD have a Shop Manual for this car) make sure the idle is also set to specs. Actually the idle should be set slow enough so that the mechanical advance is not coming into play in the first place when adjusting the timing. If I remember correctly the final idle is set by adjusting the anti-dieseling solenoid, not the carburetor itself (after the carburetor is adjusted correctly).
You really SHOULD have the Shop Manual for this car! Check for them in eBay or from outfits such as Crank 'en Hope and many other sources that sell original or repros of shop manuals.
I have found a shop manual for the car on ebay. I will buy it now. Where is the anti-dieseling selenoid located?