Hello there knowledgeable Miata people. A friend of mine has left me his '92 Miata that he purchased yesterday to diagnose, and I'm a bit perplexed. It's an automatic with 36K miles. It's absolutely gorgeous! It's been owned by a woman driver who pampered the car it's entire life. Some time ago, it developed a strange performance problem that it's original owner no longer wanted to tolerate, and an issue that general mechanics have since been unable to correct. As a result, my friend has purchased the car at a very very affordable price, especially for such a fantastically cared for car.
The issue seems to relate to a problem restarting the car after it's been driven a while. I drove it all day today and found nothing wrong until late in the afternoon, having driven it all morning, I arrived home, ate lunch, and when I got back in the car, it would not start! The car turns over fine. No battery or starter problem at all. The problem is a failure, or a very protracted time to get the car started, and when it does finally start, it smokes black for a short period of time. This is perhaps from the 6-8 attempts to start the car just prior, but the original owner has reported this problem over time and shows in the way the car has been handled by the mechanics she's taken the car to. Her same complaints have led mechanics to replace the air mass meter and air flow sensor ( I think this is what they are called). The air filter has been replaced. The plug wires may be original factory wires (they're black and certainly not NGK's). When the car runs, it runs fantastic! Every once in a while, it seems to lunge a bit unexpectedly at a light with my foot on the brake, at idle, but nothing that has scared me too seriously. My first thoughts are the 02 sensor, but would these characteristics point to that? True the 02 is physically 11 years old, but again, the car has 36K miles on it. My other thought seems to lead me to think that it's electronically related, like a wire that allows that car to turn over perfectly, but prohibits the car from actually starting, and when it finally does start, it's got a load of unburned fuel in the chambers that cause it to smoke black. When it does finally start and the black is burned out, it runs fine. A wire that is somehow affected by temperature contraction/expansion that when a certain temperature (i.e. in between normal operating temperature, and especially durning some time in the cool down period, and at the other extreme, when it's completely cooled). Any ideas would be greatly appreciated, especially from those of you who might have had this problem and rectified it. Thanks in advance for any thoughts/help!!!
Sincerely,
Jay N. Beechcraft