» » »

Mercury Q&A

Ask Your Question

1994 Mercury Villager Question: What would cause a rough Idle.

 

Question

zmassive, 3.0L V6, Moberly, MO, January 02, 2012, 00:26
 Enthusiast

The van runs fine and has plenty of power on acceleration. Idles at normal rpm, Idel air control motor is working good, egr valve works good by manual depression. Vacuum is steady at 15 inches of mercury. Inspected spark plugs, no problems found, cleaned rotor, distributor cap and inspected plug wires. No emission codes. It's not to bad in park but is very noticeable and sounds like it's going to die at a stop in drive.
Thanks

1 Answer
Flag This
  • Answer #1

    PARTS GUY January 02, 2012, 02:48
    Profile_thumbnail
     Master

    15 inches of vacumm is not acceptable. You don't clean a ignition rotor. When was the last time you changed the plugs? When was the timing belt changed?
    When was a fuel ignition last performed?

    Flag This
  • Reply

    zmassive, January 05, 2012, 02:08
     Enthusiast

    This is a 94 mercury villager and an article I have from alldata says that 14 to 22 inches of mercury is normal at idle. The distributor cap was cleaned of build up on the contacts. Plugs are 25000mi old and are platinum, they have some beige color buildup on the insulators. I don't think the timing belt has ever been changed. What is fuel ignition?

    Flag This
  • Reply

    PARTS GUY, January 05, 2012, 06:16
    Profile_thumbnail
     Master

    When you clean a ignition rotor you widen the gap between the rotor and distributor cap. Hence requiring the ignition system to jump a wider gap which means it requires more voltage. You say you read that 15 inches is acceptable, it is not. Your villager is 18 years old, I strongly suggest that you change the timing belt before you have to change the engine. It is an interference engine. What I also meant to say was a Fuel Injection Service.

    Flag This
  • Reply

    ziptie12, June 27, 2012, 13:06
     Master

    it's almost july.I wonder if he bought another motor yet? ..15 inches of vacuum is acceptable if you have restricted exhaust or retarded timing (for any number of reasons ...like lack of maint. eh?

    Flag This
  • Reply

    zmassive, July 09, 2012, 19:54
     Enthusiast

    Found the problem, Intermitent knock sensor. back to normal. Thanks for your help.

    Reply
    Flag This