I bought a 91 Spirit RT a couple of months ago. It has 150k miles, rebuilt engine, great shape. However, I'm having an intermittent problem that I need help with. A large part of the time it runs really well-no problems. But at other times it will 'skip' or 'hiccup' while I'm driving it. It seems to be worse after I have really pushed the car. My mechanic (who is good but not an expert on TIIIs) found a couple of vacuum leaks and fixed them. He cannot hear any more vacuum leaks. When this is happening it seems to idle high (around 1500 rpms). The rest of the time is idles around 900 rpms. The car has never 'died' on me when this is happening. I'm getting good gas mileage-around 28 mpg. Also, it is showing no codes. The car was not driven for probably 6 months before I bought it. Anyone have any ideas? Thanks in advance for any help you can give me. djd.