I have a turboed 2.8 4-speed that I've replaced practically all sensors, fuel pump, filter and injectors, etc. It runs much better than when I got it, mainly due to the injectors, but now it almost dies when coasting not under load. It will come back to life when I hit the gas with a bit of a jerk. No PCV valve, no vacuum leaks, MAP sensor tested okay. I did some research and saw TPS as a possible cause, idle adjustment screw, and someone solved a similar issue because there was too much teflon tape on his temperature switch (needs to be grounded). Any other opinions or ideas of what to look for?

Timing or iac valve.
Clean the iac passages. The iac is responsible for idle. Usually only comes into play at around 4mph or under and no throttle.
Check timing.

The VSS sends a signal to the computer to tell the engine how to idle between shifts and coasting in neutral. Is your ECM original, and for a stick shift?

quote Originally posted by Gall757: The VSS sends a signal to the computer to tell the engine how to idle between shifts and coasting in neutral. Is your ECM original, and for a stick shift?

good question. I have the original builder's phone number so I will call him and ask if he knows.