This is a question for the experts. Seven months ago, I purchased a 1991 Mazda RX7 13b convertible. It started well and ran OK at the time when I purchased it. At that time I also owned a 1981 RX7 and I wanted to drive it so I could sell it. I started up the 1991 at least once a week and let it warm up well. After 1 month it became very hard to start. It would start on the front rotor only and take 15 to 20 seconds before the rear rotor would start to fire. I pulled the plugs on the rear rotor and they were both soaked in oil. I asked about this on this forum and was advised that the oil seals on the sides of the rear rotor were worn out and I needed to overhaul the engine! Miles were at 71k. This seemed very low to need an overhaul. I drove it like this for five months and it was always hard to start. Even when it was warmed up. The exhaust would smoke blue at cold startup but never after it was warmed up! I then installed a separate metering oil injection system. I installed the spacer under the metering pump that isolates the metering pump oil from engine oil. I only did this because I wanted to be sure that the apex and edge seals were getting oil. This way I could also measure the amount of oil burned. I used 50% 2 cycle synthetic oil and 50% seal restoring oil additive. After 6 weeks, the engine starts very well in the morning. Always on the first time without pressing the gas pedal. Even better when it is warmed up. It is like a new car now. My question is, can anyone explain why the oil was on the rear plugs when it was not starting well and the source of this oil?

 

was the engine in this car stock? or had someone messed with it and removed the omp?

 

I've only owned it for about eight months but the the best I know is that the engine is original and stock but I did move the OMP. The problem I had with oil on the plugs occurred before I moved the OMP. Thanks, Dave

 

hmmm sounds weird. was the vacuum hooked up to the oil injectors? im not exactly sure how the oil injectors work so maybe someone can chime in on that.