[RemoteUzer]

Hello, I've looked around but couldn't find anyone with my exact problem. It started off as just the digital speedometer on my 1988 Cutlass Supreme 2.8 cutting out occasionally. After a while, I would let off the gas and shift into neutral, to coast to a stop (manual transmission here), and the engine would jump to 2-3k RPM. Now it's to the point where the speedo still cuts out (quite frequently) and anytime I take my foot of the gas, the engine dies--extremely weak idle. I've replaced the VSS (no problem with original), I've cleaned the TB thoroughly to try to fix the idle problem, I've checked the IAC valve and it reads OK, I've shorted the diagnostic port but it only reads a code 12 ("all systems okay"). Basically, it's got to be something after the ECM otherwise it would be yielding a code (ie-broken sensor, malfunctioning circuit, etc) but I can't track it down. My two guesses at this point are either the Cruise Control Module or the ECM itself. Any suggestions? Thanks for your help!