My 2003 Mach 1 randomly started to hold an idle in the 1500-3000 range. While driving in gear it pulls like in cruise control. I swapped out the IAC and PCV for new ones. I also tested the MAF by unplugging which killed the engine. The area in the engine bay near the intake sounds louder than normal while idling. I ordered a IAC reducer gasket and am waiting to receive it. Full trim is all over the place bouncing from +5 to +25 Any thoughts of what to check next?
High idle 2003 Mach 1
- Thread starter JohnnyUtah
- Start date
squeak93
15 Year Member
Agreed on a vac test or spray some carb cleaner etc around the intake gaskets. Sounds like a vac leak/unmetered air is getting in. But hard to say via the interwebs diagnostics committee.
Found the issue. I unplugged the IAC while the engine was running, engine almost stalled, plugged back in, boom back to normal idle. Maybe a bad connection or something
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