p0507

[98ranger3.0]

i have a 98 ranger 3.0 standard trans trucks idles around 1500-1800 rpms while driving i push the clutch in and it jumps to 3000 rpms ive changed the iac the pcv and the pcv hose no change tried spraying carb cleaner all over the engine couldnt find any leaks any one have any ideas...... is there a chance the iac i got was junk

 

[RonD]

Welcome to TRS

After engine is warmed up and idling, unplug the IAC valve's 2 wire connector, IAC Valve will close all the way without power

RPMs should drop to 500 or engine may even stall, either is good it means no vacuum leak.
If idle stays 700 or higher then there is an air leak.
Leave IAC unplugged and pull off 1 vacuum hose at a time from intake and cover that port with your finger, if idle drops then you found a leak.
Start with Power brake hose then PCV hose, yes you replaced it but test it anyway


If idle does drop to 500 or engine stalls when IAC is unplugged then computer is setting the high idle, or the IAC Valves wiring is shorted to ground somewhere.
Computer pulses the Ground wire on the IAC Valve to set idle, if that wire is shorted to ground the IAC Valve would stay open all the time, and that would cause P0507