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How To Tune Up Your 199, 232, or 258 Six With Points Type Ignition

One of the things you need to do periodically is tune up your car. The work involved is pretty easy but there is an order you have to follow or you'll never get the car tuned correctly. You should also be aware that a proper tune up can take several hours (or longer) to perform.

Here is a list of the tools you'll need to do this job:

• Compression test gauge
• Dwell meter
• Tachometer (don't rely on factory gauges for this, they are frequently not accurate or sensitive enough).
• Vacuum pump
• Flat head and Philips screw drivers
• Spark plug socket and socket wrench
• Points file
• Ohmmeter
• Feeler gauges
• 1/2" box or open end wrench
• Tune up specifications for your car. These can generally be found in your owner's manual, your shop manual, or on the emissions sticker (1968 and later).
• Other hand tools such as pliers and wrenches to disconnect electrical terminals and fuel lines.

There are two types of tune ups that you'll need to do depending upon the mileage since the last tune up and how poorly the car is running. The first type is a minor tune up which involves visually inspection of the fuel and ignition systems and minor repairs such as replacing filters or ignition system parts (points, cap and rotor, plugs, etc...). The second type is a major tune up which will also involve rebuilding the carburetor (here is how to rebuild a Holley model 1931). I typically do a major tune up when I first get a vehicle and then yearly minor tune ups. If you drive your car year round, you'll likely need to do minor tune ups twice a year (spring and fall) to keep the car at it's peak performance.

Regardless of which type of tune up you'll be doing, you need to start with making sure that the engine is in good mechanical condition. To do that, you'll need a compression test gauge. To check the engine's compression do the following:

• Make sure the battery is fully charged and the cables are clean, tight, and in good condition. This will ensure that you don't get false readings from a weak starting system.
• Disconnect the coil power wire from the coil. This is the yellow wire connected to the + terminal on the coil. The - terminal should have a wire going to the distributor, if the wire are improperly connected, fix that now since this will cause the car to run poorly.
• Number the spark plug wires so you can tell where they go. The #1 cylinder is the one at the front of the engine.
• Remove the spark plugs. As you remove them, take a few moments to inspect them. If there are hard black deposits on them, the engine is burning oil. Softer black deposits (sooty looking) are caused by a rich fuel mixture or other carburetor problems.
• Remove the air cleaner assembly and block the throttle and choke plates fully open.
• Connect the test gauge to each cylinder and crank the engine. You want the engine to make several revolutions (at least 4) until the maximum pressure is reached. Write down the max pressure for each cylinder. The normal pressure is around 145 PSI but the more important indication is how balanced all of the cylinders are. The cylinders should be within 10 PSI of each other. If two adjacent cylinders are low and of equal pressure, that indicates a blown head gasket. If all cylinders read low (under 120 PSI), the cylinder bores are worn and the engine needs to be rebuilt. Note: If the engine has been sitting for a long time, you may have low cylinder pressure until the car has been driven a few hundred miles since the rings may be stuck or slightly damaged from rust. It is okay to proceed with the tune up in this case. Using a top engine cleaner prior to tuning the car up will help in loosening the rings up.

Once you've verified that the engine is in good mechanical condition, it is time to do the actual tune up.

Distributor Service

1. Remove the distributor cap and set it aside.
2. Gently twist the rotor. It should move slightly and snap back into place. If it doesn't move or doesn't snap back into position when you release the rotor, the mechanical advance is sticking or seized. You will need to remove the distributor to fix this.
3. Disconnect the vacuum advance vacuum hose. Inspect the hose for cracks or softness and replace as needed. Plug the hose it with a sharpened #2 pencil or golf tee.
4. Connect a vacuum pump to the vacuum advance can and apply vacuum to it. The points should rotate slightly when vacuum is applied and it should hold the vacuum. If the points don't move, you'll need to remove the breaker plate for further inspection. If the vacuum advance doesn't hold vacuum, it must be replaced.
5. Remove the rotor and set it aside.
6. Inspect the cam lobes for excessive wear (grooves on some or all of the lobes, or flattened lobes). If the lobes are damaged, you will need to replace the distributor.
7. Remove the felt disc under the rotor, lightly oil it with engine oil, and return it to its proper spot. It should be wet but not dripping. If the felt was very dry, you may need to oil it several times to fully saturate it. If you get it dripping wet, gently squeeze it in a shop towel to remove the excess oil.
8. Inspect the points for burning and large material transfer (more than .020"). These problems generally indicate a failed condenser. You will need to replace the points and condenser if you find this condition. If the contact material on the points is mostly gone, you will also need to replace the points and condenser. If you are not replacing the points and condenser, gently file the points smooth if needed. Note: some material transfer between the contacts is normal and actually desirable. Inspect the point set to make sure the contacts are aligned with each other. Correct the alignment or replace the points and condenser as needed.
9. If you replaced the points, mark the distributor location on the engine block (chalk works well for this), loosen the distributor hold down clamp and rotate the distributor until the rubbing block on the points is on the high spot on the cam. Set the point gap to .016". Rotate the distributor to its previous position and tighten the hold down clamp. If you didn't mark the location of the distributor, set the hose nipple on the vacuum advance can so it is parallel to the engine block.
10. Inspect the rotor for burning, cracking, and excessive wear. Replace as needed.
11. Inspect the distributor cap for cracking, burned or pitted contact, and carbon tracking. Replace as needed.

How To Line Up Your Distributor

If you had to remove the distributor or it is not properly installed already, here is the procedure I follow to properly reinstall it. If the distributor is in the car already, start with step 1. If it is out, start with step 6.

Here is how to do it:

1. Disconnect the power wire to the coil.
2. Remove the air cleaner assembly (this prevents a back fire from setting your air filter on fire).
3. Pull the #1 spark plug, put your finger near the plug hole, and "bump" the engine over until you feel pressure on your finger followed by suction (this is the point where the engine is just past TDC).
4. Line the mark in the balancer with the zero mark on the timing pointer (this puts you at TDC on the #1 cylinder).
5. Remove the distributor cap.
6. The rotor should be pointing towards the radiator and parallel to the engine and the vacuum advance canister should also be parallel to the engine. Here is what a properly installed distributor looks like:
   
   If these are not parallel, you need to remove the distributor and line it up properly. You may need to use a long and thick flat blade screwdriver to turn the oil pump drive shaft. This would be a good time to oil the felt underl the rotor with engine oil. It should be wet but not dripping.
7. Once it is lined up, connect a continuity tester (or a self-powered test light) to the - terminal on the coil and ground. Rotate the distributor until the point open (continuity tested shows an open circuit or light goes out). Tighten the distributor. This will get the timing pretty close to TDC which will allow the engine to start.
8. Re-install the distributor cap and make sure the plug wires are connected properly. The #1 terminal on the cap is the one next to the vacuum advance can on the engine side.
9. Re-connect the coil power wire.

At this point, the engine will either start up or back-fire through carburetor. If it back-fires, the distributor is 180 degrees out. You can either move the plug wires on the cap or pull the distributor back out and turn it 180 degrees. The engine will not care either way but it is best to rotate the distributor

Spark Plugs, Wires, and Ignition Coil

1. Inspect the spark plugs for damage (cracked insulators, damaged contacts, etc...) and clean or replace as needed. Set plug gap to .035" and install the spark plugs. Note: Use of platinum tipped spark plugs is not recommended for points style ignition systems. They do not provide enough spark energy to fire these types of plugs efficiently.
2. Inspect the ignition wires for damaged boots or insulation. Make sure to flex the entire wire into a U shape and inspect for cracks on the outside of the U. Damaged wires must be replaced. Once the visual inspection is completed, check the resistance with the ohmmeter. The coil to cap wire should be 7,500 to 12,000 ohms per foot and the cap to plug wires should be 3,000 to 7,000 ohms per foot. Replace any wires that fail this test.
3. Install the spark plug to cap wires making sure that they snap into place. If any of the wires do not snap into place, you must fix the problem or you will have a misfiring cylinder.
4. Inspect the coil for physical damage (rust outs, loose terminals, breaks in the coil wire tower or top of the coil) and replace if needed. The ignition coil is oil filled so any oil staining on it may indicate it is leaking. A valve cover leak can also make oil stains on the coil so you will need to remove the coil and inspect it further. Note: Depending upon the model and year car you are working on, the coil will have either an internal resistor or an external resistance wire. If you have to replace the coil, make sure you get the proper style.
5. Ensure that the power wire is connected to the + terminal and the - terminal is connect to the distributor. Correct as needed.
6. Install the coil to distributor cap wire.

Ignition System Adjustments

1. Clean the timing pointer on the engine and mark the notch on the crank damper.
2. Start the car and allow it to warm up. Once it is warm enough to run at normal idle, check the point dwell. It should be between 31 and 34 degrees. A wider point setting reduces the dwell angle and a narrower point gap will increase it.
3. Set the idle speed to 500 RPM or less (you may need to back out the fast idle screw to do this).
4. Adjust the timing to the specification. You can find this in the owners manual, in the service manual, or on the emissions sticker (1968 and newer cars).
5. Reconnect the vacuum advance hose.
6. Adjust the idle speed to 550 RPM in drive for automatics or neutral for manual transmissions.
7. Shut off the engine.

Carburetor Adjustments

1. Remove the air filter and clean or replace as needed.
2. Remove the PCV filter from the molded hose leading to the valve cover. Clean with solvent and lightly oil with 20 weight oil.
3. Reinstall the air cleaner assembly,
4. Remove the PCV valve from the valve cover and start the engine. Place your finger over the end of the valve. You should feel a vacuum and then the valve should snap shut. Replace if it fails this test.
5. Restart the engine and allow it to reach normal operating temperature.
6. Adjust the fuel mixture as outlined below:
   1. Slowly back out the fuel mixture screw until engine speed drops off.
   2. Slowly turn the screw in until max engine speed is reached and continue turning it in until the speed drops off again.
   3. Slowly turn the screw out again until the max engine speed is reached.
   4. If there is more than a 50 RPM change in speed from where you started at, repeat the procedure.
7. Set the curb idle speed to the specification. Generally, that is 525 RPM in drive for automatics and 600 RPM in neutral for manual transmissions.
8. Adjust the fast idle speed to specifications.

Last Updated 09/25/10 10:21:29 PM