So I sold my miata in June of 2011. For anyone who needs a refresher, it was a 1990, 97 1.8 motor swap, gt28 godspeed turbo, AEM EMS standalone, etc etc. I dyno'd at 263whp on stock internals. I didn't drive the car a lot, and it ran fine.

Guy who bought it from me had the car parked for pretty much all of his ownership. Shortly before he sold it in September he drove it to California where it proceeded to overheat constantly. I had the car tuned for 94 octane and he wanted to be able to run 91. The car didn't have insurance (can't drive a car up here without it), and he asked me to retune it without being able to drive it. So I fattened up the fuel curve in boost and took out some timing. I'm sure this contributed to it overheating.

Anyways, the new owner is mechanically inclined and has obviously worked on many cars. He bought the car to use as a track car for both autocross and drag racing. But this also means the car for the most part sits idle. On Saturday he asked me to help him with tuning so we went out and I retuned the car to a much leaner setup. We were going down the highway and the car was running great. We had to get off the highway and got into a left turn lane. While idling, a large amount of smokey, burning oil exhaust was coming out. The car idles at about 750RPM, and as soon as he opened the throttle up a bit, the exhaust went away. So it's only burning only under heavy vacuum. The current owner said it did that right after he bought it.

Any thoughts? Once again, car has been parked for most of the past year and a half. Only smokes bad when lots of vacuum is present.

 

How many miles/kilometers/hectares are on the motor?

It probably overheated in CA because the ducting is inadequate for the average temps there, vs way up North in Victoria. Search around for threads on radiator ducting here, if there's none on the car currently.

 

Condition of PCV valve?

 

Motor has roughly 80,000km on it. I suggested the PCV valve. He took it off and all appeared to be well.

 

Leak test then never speak to them again, not your problem.

 

Haha I know it's not my problem, I'm happy to help the guy out.