Wish you could have a quick-reference checklist for those perplexing problems that crop up from time to time? Engine won't start. Battery won't stay charged. Transmission slips. Clutch chatters. Brakes pull to one side. Driveline squeaks like a spastic squirrel as you come to a stop. Instruments have stopped working. Left turn signal won't blink. Headlights have left you in the dark. Rear axle whining like a disgruntled politician.
Bewildering problems, yet most are simple to solve given a handy checklist. It's easy to get lost in the details to the point where we miss the most obvious things. Our goal here is to get you back on course as quickly as possible.
The best advice we can offer is to begin your troubleshooting with the simplest items first. When an engine quits, it's only natural to panic and think the worst. But, did you remember to put gas in the tank? Most of the time, it's a broken wire, busted distributor rotor, bad ground, cracked distributor cap, ruptured fuel pump diaphragm, faulty ignition switch, or you've run out of gas. So always begin your search with the most obvious stuff first. Start your troubleshooting at the source.
Even if your engine won't...
Even if your engine won't crank, make sure you have 12-14 volts of battery power. This may seem obvious, but it doesn't always get our attention right away. Start with the easiest item on your checklist.
- Check the battery, which should show 12-14 volts with a voltmeter.
1: If the battery has at least 12-14 volts, verifiable with a digital voltmeter, check the starter solenoid. When the ignition is turned to "Start," does the solenoid click? Clicking means power is getting to the solenoid.
2: If the solenoid clicks, is there power at the starter cable terminal?
3: If there's power at the starter cable terminal, check the starter cable and starter.
4: If the solenoid does not click, check for power at the "S" terminal with the ignition switch at the "Start" position.
If you have 12-14 volts of...
If you have 12-14 volts of battery power, check the starter solenoid and all related connections. The "S" connection should be live when you turn the ignition switch to start. The "I" connection, which should also be live in "start" mode, fully energizes your Mustang's ignition coil during starting.
If there's power at the "S" terminal with the ignition switch in the "Start" position and the solenoid does not click, replace the solenoid.
Other starting system items to check
1: Check engine to firewall ground strap for proper contact.
2: Check battery to engine block negative cable for proper contact.
3: Make sure battery terminals are clean and corrosion free.
4: If the battery is dead, have it deep cycle (trickle) charged, then load tested at your local auto parts store. If it fails the load test, the battery will need to be replaced.
If the starter operates (spins),...
If the starter operates (spins), but does not turn the engine over, it's either starter drive (known as the Bendix) failure or a flywheel/flexplate issue (damaged teeth or improper starter drive engagement).
Give the starter a gentle whack with a hammer to jar brushes in order to improve contact. Sometimes, brush contact with the slipper is lost due to debris or oil. If that doesn't work, remove and inspect the starter.
2: Spray brushes and slippers with high-evaporation rate radio tuner cleaner or brake cleaner to rid them of debris and oil.
3: If it isn't poor brush contact, check all leads within the starter.
4: Have a reputable starter/alternator/generator shop check your starter.
Is there fuel in the carburetor?...
Is there fuel in the carburetor? Sounds elementary, but it's so easy to overlook when you fear it's something worse.
- Is there gasoline in the carburetor?
1: Remove air cleaner and work the throttle. Does fuel spray into throttle bore?
2: If not, is there fuel in the float bowl? If there is, you have a faulty carburetor accelerator pump.
3: If there's no fuel in the float bowl, is there fuel in the tank? Don't laugh, this happens way too often.
Don't forget to check the...
Don't forget to check the fuel strainers or screens found in some carburetors. They can clog, especially if they've been in use for quite some time. They're more common with Holley carburetors than Autolite and Motorcraft.
If there's fuel in the tank, disconnect the fuel line from the carburetor and have a helper crank the starter. If there's no fuel on the pressure side, check the fuel supply at the pump. If there's fuel, you have a faulty fuel pump or blocked fuel line. Check the fuel line between the tank and pump for debris, faulty hoses, or a damage (kinked or smashed) fuel line.
If there's fuel, check the ignition.
1: First, check for a spark by taking one spark plug lead and grounding the spark plug to the engine. Have someone crank the starter while checking for spark. (Don't lean against the car body or you could get shocked).
2: If no spark and you're still using traditional points (as opposed to an electronic ignition conversation), remove the distributor cap and inspect for badly pitted or damaged points, improper point gap, faulty breaker plate ground wire, cracked distributor cap or damaged rotor, or damaged ignition coil primary (-) lead.
3: If no spark and you've inspected the distributor, check for power at the ignition coil's positive terminal (+) with the ignition switch in the "on" position. Then check for power at the coil's positive terminal while cranking the engine.
Remove the air horn and examine...
Remove the air horn and examine the fuel bowl. A float set too high or a sticking needle valve will cause flooding and a no-start condition. Fiber floats eventually become fuel soaked and sink, causing flooding. Brass floats can develop a leak and sink, resulting in flooding. The smell of raw gasoline is your first clue.
If there's power at the positive terminal but no spark at the secondary harness, suspect the ignition coil.
5: If there's no power at the coil's positive terminal with the ignition on and while cranking, suspect the ignition switch or its resistor wire.
6: If there's no power at the positive terminal with the ignition switch in "start" mode, check for power at the "I" terminal on the starter solenoid. "I" is what fully energizes the ignition coil with 12 volts during start.