High Idle on a 1985 Grand Marquis

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

25,665

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.
69,295

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

69,295

*- fast idle CAM. Sorry! -Jim

Your Answer

Add photo

Related Questions

Grand Marquis

Looking for a Used Grand Marquis in your area?

CarGurus has 5 nationwide Grand Marquis listings and the tools to find you a great deal.

Postal Code:

Search Mercury Grand Marquis Questions

Mercury Grand Marquis Experts

#1 Tracy Hooks
Tracy Hooks
Reputation 5,700
#2 kbro
kbro
Reputation 2,120
#3 Js08016
Js08016
Reputation 1,840
View All

Related Models For Sale

Used Ford Crown Victoria
10 listings starting at $5,995
Used Lincoln Town Car
13 listings starting at $1,850
Used Chevrolet Impala
57 Great Deals out of 928 listings starting at $1,900
Used Dodge Charger
79 Great Deals out of 844 listings starting at $1,999
Used Ford F-150
428 Great Deals out of 9,032 listings starting at $922
Used Ford Mustang
9 Great Deals out of 1,204 listings starting at $2,995
Used Ford Taurus
22 Great Deals out of 301 listings starting at $4,900
Used Buick LeSabre
14 listings starting at $2,500
Used Honda Accord
66 Great Deals out of 1,131 listings starting at $748

Used Cars For Sale

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.