1994 Mercury Topaz idles too fast in park or neutral

1994 MERCURY TOPAZ
115,500 MILES • 4 CYL • 2WD • AUTOMATIC
Avatar
RLPCHILE
  • MEMBER
  • 1 POST
Hello,
My 1994 Mercury Topax 4 cylinder idles at about 1000 rpms when stopped and in gear; however, when I put the car in park or neutral, the idle becomes unstable between 2000 and 3000 rpms. A mechanic tried using throttle body cleaner and lubricant, but it didn't really help much. I hope you have an idea of what to do. It is a good car and runs very well.
Thank you!
Richard
Aug 3, 2008 at 4:35 PM
Advertisement
Avatar
MMPRINCE4000
  • CERTIFIED EXPERT
  • 8,548 POSTS
Inspect all the vacuum lines, injector seals, power brake line and intake manifold gaskets for leaks, cracks etc.
A high idle is generally a vacuum leak. I would clean the idle air control port in the throttle body, but generally you will be looking for a cracked/ripped vacuum line.
Aug 5, 2008 at 5:09 AM