Hello,

recently replaced the IAC and TPS on my 1994 3.0L and know when starting the RPM accelerate quickly and slowly come down. When driving and letting off the gas to shift gears the RPM’s will stay advanced or even rev up on its own. Is there a relearn process I must follow? I disconnected the batter in hopes it would rest the ECM but no luck. Any advice?

 

Welcome to the forum

RPMs should hold or go up a little(depends on load when clutch is depressed) when shifting, but if you leave clutch pedal down for 5 seconds RPMs should drop to about 1,100 and stay there until speed is under 5MPH, then it should drop to warm idle level
This is an emissions requirement, lower RPMs = higher pollution

After engine is fully warned up, and idling, unplug the 2 wire connector on IAC Valve
RPMs should drop to 500(barely running) or engine may even stall, either is GOOD, it means no vacuum leaks
If RPMs do not drop then you have a leak OR someone has mis-adjusted the anti-diesel screw on the throttle linkage

 

Thanks RonD, I’ll give this a go.