Starting System

Troubleshooting

Slow/Intermittent Starting
No Starting

Slow/Intermittent Starting

If your Fiero seems to be turning over slowly I would suggest the following steps (not necessarily in order of likelihood, but rather ease of checking):

Use a good voltmeter to check the battery voltage. Voltage should go up with the engine running about 2000 rpm.
Check the battery water level (I cover the battery with a towel when I pop the caps to catch any acid that may spray).
Remove and clean the battery terminals and cables with a wire brush. After reassembly, coat with grease or vaseline to prevent corrosion. (Be careful to never hit the wrench to metal).
Check the positive battery cable to starter connection. This was the source of all my problems. As you have to work near the exhaust, wait until the car cools. Disconnect the battery cables, as otherwise it will be an electrical disaster if you hit any metal with the wrench while tightening this connection. It took a 15 mm wrench, putting the car up on blocks, and some arm contortion to get it tightened.

From: David Detienne

Car will not start

Here are some things to check for when troubleshooting a starting problem:
Car will not crank
Car cranks, but will not start

Car will not crank

Check the battery voltage with real voltmeter, not the one that you may have in your dash (depending on options) which is known to be innaccurate. If it is below 11.8 volts, have your battery charged. There may not be enough power to turn the starter over.
Listen for the starter solenoid to engage when you turn the key. You should here a click from behind you (from the solenoid attached to the starter).
If there is no click and you have a manual transaxle, check the Neutral Start Switch. It is located near the top of the clutch pedal. If you have an ohmmeter, you can check the resistance of it. If not, you can take a piece of wire and stick it in the connector instead of plugging it into the switch. If the car now starts, that's your problem.
If there is no click, or if there is and the rest of the car suddenly loses power, check for loose or corroded battery terminals.
If there is a click, but still no cranking, your starter motor itself is bad.

Car cranks but will not start

There are two likely causes of this. One is a fuel delivery problem, and the other is an ignition problem.

Turn the key to the run position. Do you hear the fuel pump run for a second or two? Note that it does not do it EVERY time you turn on the key, just when it's been several seconds or more, and the fuel system needs to be repressurized.
If you don't hear it, you need to check your fuel pump relay.
If you do hear it, the fuel pump is probably not your problem.
Check for firing injectors. On the four-cylinder, this is simple. Take off the air cleaner and you can see the injector spray fuel. It should spray a nice conical shape. On the V6, you can't see the injectors, but if you have a voltmeter, you can test whether they are being fired. This won't necessrily eliminate them, but it is unlikely that all of your injectors would go bad at once. Unless you got something bad in your gas, or you are out. (You DID make sure you're not out, and that it's not your gas gauge which is bad, right?)
To test whether the ECM is firing the injectors, disconnect the large flat six-connector wiring harness located near the passenger side of the rear (closest to the trunk) valve cover. Each set of two pins can be tested with a voltmeter. The first two power three of the injectors. The middle two fire the other three injectors. The last two fire the cold start injector (only fired during cranking, when the engine is cold).
If they aren't firing, you have a wiring problem or an ECM problem. Don't forget to check the fuses. There are two, one for each bank of injectors.
If you didn't find anything wrong with the fuel system it's time to check the ignition system. The easiest thing to do, is to take off the distributor cap (don't disconnect the plug wires) and look at the metal contacts on the inside. If they are covered with corrosion (flaky white stuff), then take a screwdriver and scrape it off. Note that if it is very corroded, it may mean the contacts are too worn and need replacing. If your cap needs replacing, your wires probably do too. But you can test a few other things for free, before you spend the $20-$30 for a new cap, rotor, and set of wires.
One of the most common causes of ignition problems on the Fiero is the ignition module. Many parts stores will test it for free, or you can buy a $30 tester that will do it for you.
If you don't have anywhere handy that will test it for free, disconnect the wire leading from the coil, at the distributor. Set it so that it is next to something metal, like one of the nuts on top of the strut tower. Have someone crank the car, while you watch (not too closely!). You should see an arc of electricity from the wire to the metal. If not, your coil is not firing. This means either your coil is bad, or your ignition module is bad.
If it did arc, then check the individual spark plug wires in the same way. You should see a nice blue arc every time. If you get a good spark on some wires, and not on others, replace the wires. Then re-test. If you get the same results, replace the distributor cap and rotor.
If the hold-down bolt on the distributor is missing or if you have removed the distributor, it may have become turned enough so that the timing is too far off to start the car. You will have to set the timing to fix it. If the distributor was removed, you may have to re-time the engine.

From: Sketch

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