97 SLI Ignition problem

[Frustrated 97 sl1]

I have a 97 SL1 automatic with air conditioning. It has 170K kilometers or 110 K miles. At 62K the AC died - At 110K I had to fix the tranny for $1200.

My present problem is intermittent starting. About one in 6 times we try to start the car, nothing happens, no click, no lights, no nothing. Sometimes if I move the key to Accessory, push the car back 6 inches... bingo, the car starts. The problem is not the battery. It's new and has lots of power.

I believe it is an intermittent electrical short. whee do I look for for the fault...

[Tacuvito]

First lets begin with the easy stuff. Have you checked your codes??? Places like Autozone and Advanced Autoparts will check your trouble codes for free. Not only will they check for codes off your OBDII, but tell you what these codes mean. Do that first before trying to find a short in your system.


Tacuvito.

[Frustrated 97 sl1]

Thanks, I'll have to find a friendly mechanic. We don't have autozome here
Any suggestions without the codes?

[Tacuvito]

Well here are a few test I got out of my Haynes manual.

1. With the engine switched to the "ON" position, the "SERVICE ENGINE SOON"
light should be on. This means there's ignition and battery supply to the PCM.

2.Check all ignition wiring connection for tightness, cuts, corrosion, or any other signs of a bad connection. Also check for deposits of carbon inside the spark plug boots.

3. Use a calibrated ignition tester to verify adequate available secondary voltage (25,000 volts) at each spark plug.

4. Using an ohmmeter, check the resistance of the spark plug wires. Each wire should measure approximately 12,000 ohms or less. If resistance is over 12,000 ohms, replace the wires.

5. The following test are necessary if there is no spark. Disconnect the 6 pin connector from the ignition module, and with the ignition key ON (engine not running), measure voltage on the Pink/black wire. There should be battery voltage present. If there is no voltage available, check the electronic iginition fuse (7.5 amp) in that circuit for open or short.

6. If battery voltage is present, disconnect the 5 pin connector from the ignition module and, using the ohmmeter, check the resistance of the ground wire (black/white wire). The resistance should be 200 ohms. If not, check for open or shorted circuit.

7. Disconnect the 5 pin connector from the ignition module, and working on the harness side, measure the resistance between the yellow and the purple wires. The resistance should be 700 to 900 ohms. If the resistance is incorrect remove the crankshaft sensor and measure the resistance. It should be 700 to 900 ohms, if not, replace with a new part.

8. If the resistance is as specified, check the voltage signal. Set a digital voltmeter on the A/C (alternating current) scale, while cranking the engine, measure the voltage between the yellow and the purple wire. It should be over 200 millivolts. If it is not, replace the crankshaft sensor.

9. If all the tests are correct, check the PCM and all the connector pins for bends, breaks, corrosion that might cause intermittent short or grounds.

I hope this can help you. I must advice you get a haynes car manual for an explanation on the location of the crankshaft sensor and other connectors mentioned in these tests. It will be worth it. Well hopes this helps.

Tacuvito.

[peppermrj]

Do the headlights dim when it won't start with the key in the start position?

Check the ignition switch for proper operation. When the switch is turned ON, the instrument cluster lights should illuminate and accessories such as the radio may be operated.

My guess would be the Neutral Start Safety Switch from what you have said. The link shows the testing procedure.

The starter wiring is relatively simple. One small wire that should be hot (12 volts) when the key is in the start position. The large wires are from the battery and alternator. If it does not have 12 volts at the small wire it is either the ignition switch, nuetral safety switch, fuse, or wiring that is bad.

If the small wire has 12 volts, check the large wire, connections, ignition fuse, and relay (if so equipped) for faults.

Lastly the starter could be binding. You could try smacking it with a hammer while trying to start it.

Use all caution ( jack stands ) and safety procedures while underneath a vehicle.

Good luck and let us know what happens.

[saturnspeed_12]

you could have a bad ignition switch. if you get nothing at all when you turn the key to acc or on, then id say probably the ignition switch. have you tried to turn the key several times till everything came on, without doing anything else?