- posted 13 years ago
I have a peculiar problem, but first a little background.
The other day I went to start my miata, after it had been sitting for awhile (~1 month). It was difficult, but it did start, but began to sputter and shake badly. Even backfiring a couple of times, but it continued to run (albeit badly).
I investigated under the hood, and discovered that a couple of plug wires were touching. I assumed that this was the problem, and moved the wires so they wouldn't touch.
When I got back in, I started the car and now it won't keep running.
For the brief period that it does run, it runs flawlessly. The rpms go up, just as they should and it runs smoothly, but almost as soon as it starts it dies. I suspect something electronic, like the computer is killing the engine.
I remember in a Chevy my company had there was something known as a "crank position sensor" that would tell the computer when to fire a plug, and if the computer failed to get a signal from the sensor, the computer would shut down the engine for safety. I think there must be something like this going on in my car.
Here are the symptoms:
1. Turn key, engine starts, rpms rise, then car dies within a couple of seconds.
2. If I turn the key again, the engine will crank, but not start.
3. If I turn the key to the off position before I crank it again, the engine will start/die again.
4. If I turn the key on-off-on-off-on-off-on in rapid succession, I can keep the car running, with rpms constantly going up and down, as would be expected.
That last symptom is why I think the problem isn't fuel, but electronic. Without fuel, I couldn't keep it running at all. And if it wasn't capable of sparking, it would never start in the first place. I have heard about ignition switches being a common problem, but again, I wouldn't think it would start in the first place.