E-tek How-to: Classic Tune up

by E-tek Restorations
 
Every spring, when hope springs eternal, a (real) mans thoughts turn to getting his classic car out of storage - or the shop -  and on the road.
 
Thing is, after all that sitting, along with many years of neglect, our classic rides likely need some mechanical attention. I've found that even a fully restored car needs a going through every spring like the one I'm about to describe.
 
 BASIC BODY FLUIDS
 
Fresh oil is the lifeblood of our engines. As soon as you open the hood, change the oil and filter. While it would be nice to warm the oil up to change it, I'd rather make sure there was fresh oil in it and that any condesation that gathered over the winter was gotten rid of early. We can always change it again after some testing and road time. Check for any water in the oil. It would show up as seperated if it had been sitting, or a tan-coloured soup if the engine had been running.
 
Check the coolant level. While I don't change the coolant every year (more like every 5 years), I do want to be sure it's full. As well make sure it's green, not brown or topped off with a brown sludge. If it is, have it flushed and refill with a 50-50 mix of coolant annd water. Just don't buy premixed coolant - becuase water should be free!
 
Check all the water hoses - both radiator and heater and both mid hose and the ends. If any cracking is present, change them now.
 
Also check your belts. Cracking or wear is a sign to change them, but so is age. If they;ve been on for 10+ years, reagrdless of mileage, change them out.
 
 START with STARTING
 
First off all, make sure the battery is fully charged. If it wasn't on a charger all winter, be sure to charge it - at least overnight - before beginning with the tune up. Of course if the battery has had issues in the past, if it's been bumped more times than your ex, spring for a new one.
 
Next, check the battery cables - at both ends. Each side should be new-like clean and all strands attached. Many times an entire hard-starting issue has it's origins at the block ground wire. With a Voltmeter, the battery "resting" Voltage should read at least 6.3 (for a 6-Volt battery) or 12.6 (for a 12-Volt).
 
With the meter still hooked up and the coil wire removed, crank the engine. This "cranking" voltage should not be more than 0.2-0.4 volts or 0.4-0.6 volts lower on a 6 or 12 volt battery, respectively.
 
 Of course the sounds and smells of an engine should never be ignored. I'm a big believer in using your human metering senses and I'll elude to this throughout this article. A well-tuned cranking system sounds crisp and turns the engine over fast when the starter switch is touched. Anything less than that and you need to find the draw and repair it. It's just that simple.
 
 COMPRESSION TESTS
 
I like to do dry and wet (oil squirted into cyclinders) compression tests. This will rule out most ring and/or valve issues.
 
 Both dry and wet specs for compression should be found in the engine specs tables. If a cyclinder is low on a cyclinder duing a dry test, it can signify a host of issues, including a burned valve, incorrect lash, poor ring seal or a sticky valve. By introducing a few squirts of engine oil into the cylinder you can seal up the rings. An increased compression reading would therefore point to poor ring seal.
 
 
 If your classic has an adjustable valve train, now is the time to adjust the lash. Starting with the #1 cyclinder at TDC (distributor pointing to #1 at distributor cap), adjust each set of valves. Again, these specs will be in your engine spec tables, available in your specific engine manual or online. 
 
Before putting the plugs back in, be sure to "read" them. Normal is a slight tan color on the inside porcelain, signifiying a good mixture. A black, sooty appearance means rich. If the electrodes areworn at all, repalce them. New or old, be sure to gap them to specs, then torque them with a torque wrench to 25 ft pounds. It's more than you think, which aids in sealing the cylinder, but less than an all-out two-handed crank, which may break the plug in the cylinder.
 
 
 IGNITION
 
 Start with the ignition switch. With the points open, hook up the voltmeter from the them to the battery ground and toggle the ignition switch (key, button, whatever). The volatage should be the same as the battery voltage. Also, wiggle the key in the ignition switch to simulate vibration. The voltage should not change.Turn it off slowly - a good switch will drop to 0 volts at about 1/8th turn and remain at 0. Anything different and you need to replace it.
 
Next up are the plug wires. If they are older, dirty, with cracks in the leads or boots, replace them. As with the plugs,whether new or old, check the resistance across them.
 
 New resistor wires measure about 3000 ohms per foot, so 10000 ohms should be about max for the longest wires. Whiule these are "OK" for collector cars, many wires measure MUCH less than that. To test, hook up your tester to measure ohms and hook one lead to either side. wiggle them around a bit to be sure they don't "open" when moving on a running engine.
 
 Now, gap the points (if equiped) and lube the distributor cam with either specifoed grease or moly lube. Just  a thin smear is enough.
 
Check the mechanical advance mechanism by twisting the rotor by hand and seeing if it snaps back. Apply 3 drops of oil on the wick under the rotor to lube the advance mechanism.
 
The vacuum advnace is easily checked by disconnecting the distributor vacuum line, holding your thumb over it, then advancing the plate and letting go. You should feel and hear a slight vacuum noise (pfft) when you release your thumb. If there's no vacuum, repalce the vacuum advance unit.
 
 Lastly, check the coil and distributor wires and their connections. If anything is loose, frayed or hanging by a strand, repair or replace it.
 
  FUEL IT UP
 
 Starting from the back, check the tank. If it's old, it may be time to remove it and have it professionally cleaned. As well, there are kits available (www.Eastwoods.com) to both clean and re-seal old tanks. When off, disconnect the fuel line at the carb and blow out the fuel line. Replace the flex lines to the tank and carb but only hook it up at the tank - leave it unhooked at the carb and put the  end from the pump into a gas can or 2Litre pop bottle.Make sure it won't pop out. Nows a good time to locate your fire extinguisher!
 
 Disable the ignition by removing the coil wire, or grounding the distributor end to the block. Hook up a vacuum/pressure gauge at the carb inlet. Crank the engine over and read the gauge. You should have 4 or more psi at the carb. As well, you should see several strong squirts from the pump into the bucket or bottle.
 
 


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 Next up - the carb. If it has an automatic choke, it should snap shut when you open the throttle slowly. Holding the choke plate open, pump the accelerator arm and watch for squirts of fuel from the accelerator pump.  The rest of this test will get done once we start 'er up. 
  
 Hook up a vacuum gauge to the intake manifold vacuum portand a tach to the distributor.
 
 If you've been doing all this in sequence, the carb should be set to start. If not, depress the throttle once slowly and release. Altough this start sequence has long since been forgotten by most people, doing so sets the choke, and sets the fast idel cam onto the high step. Pumping it to start won't do anything further to start a properly set up engine.
 
Crank the engine with your foot OFF the throttle. It should start up in 2-4 cranks and idle fast, at about 1200-1500rpm. Listen for clicks (tappets), knocks, or other odd noises. Oil pressure should come up to 40-80psi, depending on the engine and it's condition.
 
 The vacuum gauge at high idle should read 18 inches +/- 2. It should be steady, but you may see it surge.
 
 After a 10 minute warm up, bring the rpm to 2500. The vacuum should reamin constant. If surging is pesent, this may signify that total timing is out.
 
 Back at idle, loosen the distributor hold-down bolt. If you need to, turn off the engine to loosen it, then restart it. Watching the vacuum gauge, advance and retard the timing until the vacuum maxes out.
 
 With a light, look down the carb opening at idle. There should be no drips and the throttle palte should be dry. Now, bring the rpms up to 2500 rpm and listen for any signs of hesitation or "stumble", as well as a steady stream of fuel from the jet metering nozzle.
 
 Lastly, set and balance the idle mixture. One at a time, open the idle screws up (counter-clockwise) until the mixture is rich and the idle slows. Then, turn the same mixture screw inward until the "lean roll" point is reached (slight DROP in rpm). Now open is back up (CCW) one full turn and leave it there. Perform the same manuevre on the other side. Now the idle mixture is "balanced". The idle should end up near book value, often between 550 and 750rpm.
 
 At this point, steady state at idle or 2500 rpm should show a vacuum of 20 inches and when the rpm is dropped from 2500 to idle (foot off the gas), the vacuum should read 25 or more.
 
 CHARGING RATE
 
 With the engine still running, check the voltage across the battery. It should read at least 6.7 or 13.5 for a 6 or 12V battery respectively. This means the generator is generating a current and it's enough to charge the battery.
 
 THE TEST DRIVE
 
 Finally! Time for a drive. Things to look and listen for are: stumble or hesitation from a stop (sometimes called "tip in") as well as  Surging or miss-firing.
 
 Holding the steering wheel very lightly, press the brakes and note any pull to one side or the other. Release your hold on the wheel altogether and note any wandering or pull. Shocks should negate any bounce after hitting a bump.
 
 To check the clutch, while driving about 30-35mph, put one foot on the brake and one on the throttle. Slow the car by slowly depressing the brake pedal. At the same time, depress the accelerator. It may take a bit of practice, but if the clutch is holding, the rpm should not increase when the car is slowing down. If it was slipping, the rpm would increase while the car was slowing.
 
 That's about the scope for this article. At this point you should have a smooth running, reliable ride for spring and summer cruising - ENJOY!