High Idle on a 1985 Grand Marquis

10

Asked by Jan 15, 2017 at 08:48 PM about the 1985 Mercury Grand Marquis

Question type: Maintenance & Repair

So , I just bought a 1985 Grand Marquis from someone and it won't idle down.
I was wondering does anyone happen to know why or has had that problem
before?

3 Answers

32,445

Most common cause is vacuum leak, I believe you also have a vacuum advance on the distributor, that can also cause an idle to remain high.

1 of 1 people found this helpful.
75,555

Also, check that the automatic choke is opening up. If not, be sure you have power to the choke with the engine running. If you have power to the choke but it's not opening, replace the choke thermostat. If the choke is opening be sure the fast idle can isn't stuck or adjusted wrong. That'll give you a high idle all the time as well. The vacuum advance vacuum hose should be connected to carburetor vacuum, not intake manifold vacuum. There is a difference. Intake manifold vacuum is highest at idle while carburetor vacuum is lowest at idle. HTH. -Jim

75,555

*- fast idle CAM. Sorry! -Jim

Your Answer

Grand Marquis

Looking for a Used Grand Marquis in your area?

CarGurus has 1,521 nationwide Grand Marquis listings starting at $995.

ZIP:

Mercury Grand Marquis Experts

  • #1
    Tracy Hooks
    Reputation
    5,910
  • #2
    kbro
    Reputation
    2,210
  • #3
    Js08016
    Reputation
    1,980
View All

Related Models For Sale

Used Lincoln Town Car
13 Great Deals out of 1,587 listings starting at $1,200
Used Ford Crown Victoria
3 Great Deals out of 877 listings starting at $2,000
Used Chevrolet Impala
506 Great Deals out of 32,380 listings starting at $1,000
Used Ford F-150
3,046 Great Deals out of 230,455 listings starting at $1,300
Used Dodge Charger
326 Great Deals out of 35,855 listings starting at $1,999
Used Ford Mustang
341 Great Deals out of 42,379 listings starting at $1,488
Used Ford Taurus
194 Great Deals out of 16,161 listings starting at $1,200
Used Honda Accord
818 Great Deals out of 88,085 listings starting at $1,444
Used Chevrolet Caprice
136 listings starting at $6,995
Used Chevrolet Camaro
398 Great Deals out of 31,484 listings starting at $3,495

Used Cars For Sale

2011 Mercury Grand Marquis For Sale
21 listings starting at $4,495
2010 Mercury Grand Marquis For Sale
7 Great Deals out of 78 listings starting at $2,290
2009 Mercury Grand Marquis For Sale
80 listings starting at $3,200
2008 Mercury Grand Marquis For Sale
3 Great Deals out of 132 listings starting at $2,990
2007 Mercury Grand Marquis For Sale
116 listings starting at $1,600

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.