Started last night, initially threw a 1504 which turned out to be a loose wire at the IAC, that was fixed and car idled. As long as I keep it below 3250 car idles fine so IAC appears to be good. If taken over 3250 and IMRC's open if you engage clutch to shift rpm's will drop down and car will die if you don't shift to next gear. So my question is could the imrc's be staying open to long and maybe need cleaning? Maybe a vacumm leak although car idles fine otherwise normally a vacumm leak causes rough or low idle. Any ideas