Very strange no-start problem

I've been having a recurring problem with my 92 Riviera. I'll try to describe the problem in as much detail as possible. I've owned the car for about 6 months, perhaps less. It had about 72000 miles on it. Within a week of owning the car, I noticed a strange problem. On occasion, the car just won't start. It always (or almost always...maybe once otherwise) happens after I've driven the car, turned it off, and then tried to start it again within a short period of time. To be clear, it doesn't happen every time I turn it off and than on again quickly; It just never happens when I turn the car off and then leave it for awhile (at least an hour or two). Ive also noticed something that I think could be related. There seems to be some sort of electrical problem. When the key is in the ignition, but the engine is not running, all the electrical items in the car (dashboard, radio, clock, etc.) pulse on and off rapidly. Again, not always. It seems to happen when I, say, roll the window up or down without the engine running. The pulsating I described is also audible. Click, click, click, click, click, click. I believe what I'm hearing is actually coming through the cars speakers, but I'm not sure. I've said all that to say this; when the car doesn't start, one of a few things happen. The most common is when I turn the key, nothing happens. No sound, no clicking, no engine turning. The one thing that does happen is that while I've got the key turned, the radio and eleteical devices shut off, and then come back on when I release the key. Sometimes when I turn the key, all that happens is the same pulsating clicking noise. Usually, this problem resolves itself. Whenever the problem occurs (which is only once every 3 weeks or so), I just leave the car alone for anywhere from 30 mins to a couple hours, and when I come back, it starts. Untill now. This morning, the problem happened. I left it alone for a couple hours. When I came back, the engine tried to turn over, but didn't catch. Each time I turned the key, the engine turned over for a shorter and weaker period of time. All of this was accompanied by the dreaded pulsating clicking sound. I've tried it three times, wainting two hours between each try, with no luck. Any ideas?

I would start with this simple (or not so simple) question: Is there any aftermarket wiring in the car? Sound system or remote starter, alarm, that sort of thing? If so, you found your starting place...

Justin95riv wrote:

This morning, the problem happened. I left it alone for a couple hours. When I came back, the engine tried to turn over, but didn't catch. Each time I turned the key, the engine turned over for a shorter and weaker period of time. All of this was accompanied by the dreaded pulsating clicking sound. I've tried it three times, waiting two hours between each try, with no luck. Any ideas?

This latest episode leads me to say that you need to check your battery cable connections, make sure they are clean and tight. Also look at all the cables that go to your starter. Large and small wiring. Make sure they are clean and tight. And check that the cable that comes off the back of the alternator is also clean and tight.
Lastly, load test the battery and check what the voltage is at rest and under a load. The battery at rest should read around 12 volts and under a load should not drop below 9 volts. With all the cranking you've done recently you may have to put the battery on a charger for a period of time to bring it back to 12 volts. Won't know until you check the voltage with a meter. If you have to charge it to get it back to around 12 - 12.5 volts I recommend removing it from the car and charging on a bench at no more than 6 amps. While the battery is charging you can now look at all the wiring in the start circuit and charging circuit to clean and tighten everything.
But as Derek mentioned any aftermarket devices such as remote starters, alarm systems, etc, will cause the intermittent problems you previously mentioned. And could be the source of all of these problems. It is just a good idea to check all the cables and wiring I mentioned and the condition of the Battery to rule that out as a possibility. All free labor for peace of mind.

Well, there are no aftermarket additions so far as I know. I've checked the battery connection and it seems sound. No corrosion, either. I'll check the other connections and report back.

Justin,
If it's a side post battery you still need to remove the battery cables and clean both the battery and the cable terminal ends with a wire brush or something similar.
You can't always see light corrosion between the Battery and cable terminals and that can cause some problems.
Do you have a voltmeter to do the above mentioned checks / tests.?

My guess is you're having problems with the electrical part of the igniton switch. I think on your RIv you can open up the clamshell around the column and change out the switch. You will need to find a factory manual or Haynes manual to outine how this is done. You may want to test the wiring for resistance before you rip the clamshell off the column.

Albertj