Question about 1989 Ford Crown Victoria

1 Answer

1989 Grand Marquis 5.0 hesitation under load at 25, 40, 50 mph and slightly rough idle

89 merc 5.0 has a hesitation (dead spot) problem. I did a complete tune-up. Garage checked it, TPS and IAC are OK. They got a code 34 and 40 EGR, EVP error codes from computer.

What is the least expensive route to get this car running like it should again?

Posted by on


1 Answer

What happens when you unplug and cap the vacuum line at the EGR valve? Does the problem go away? Before doing this does the car idle rough? If so perhaps the EGR is stuck open...

Posted on Sep 16, 2008


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

I have to hit my 1992 merc grand marquis starter to i need to replace it?

Unfortunatly yes it sounds like from your descrption that you have a "dead spot" in the starter. If you have not changed one in these vehicles the top bolt can be a bear to get to, i recomend using a 1/4 inch ratchet, swivel and several differant lenght extensions to get it out, 3/8 will work but can be a tight fit..

May 24, 2011 | 1992 Mercury Grand Marquis

1 Answer

I bumped my neighbors 1989 merc grand marquis. Totally demolished passenger side tailight cover (the red thing). Need replacement

mcdevito75 here, Check your local junk yard, other thann that you can check ebay or you may have to go to the dealer Ford for a brand new lens, (RED)

Jun 17, 2010 | 1989 Mercury Grand Marquis

1 Answer


You may have a bad switch or a wiring issue

Apr 29, 2010 | 1989 Mercury Grand Marquis

1 Answer

My 2000 mercury marquis misses at about 40-50 mph.i have changed the spark plugs and boots. i have also flushed and cleaned the ejector and throttle body.

You may need to clean under the airhorn. The EGR vacuum passages can get clogged and it throws off the system. The other part would be the throttle position sensor. It may have a rough spot on the rheostat, you can connect an ohmmeter and work the throttle by hand and perhaps see a lack of response.

Oct 29, 2009 | 2000 Mercury Grand Marquis

2 Answers

Merc Grand Marquis, starts, idles rough for few seconds and dies.

HI if you rev up the rpms does your light stays on ,If thats the case you need to replace your alternator have it check at autozone or rally s auto parts for free

Sep 25, 2009 | 1993 Mercury Grand Marquis

1 Answer

What is an ignation tune up for a 99 Merc. Gnd.

A full ignition tune up would be new spark plugs and wires.A cap and rotor if it has those. Do any fuel system cleaning before changing the plugs.

Jun 22, 2009 | 2001 Mercury Grand Marquis

2 Answers

Headlights work but dash lights and parking lights are dead

dash and tail sre tied together, so chk tail light fuse.

May 13, 2009 | 1989 Mercury Grand Marquis

1 Answer

89 Wagoneer drives rough

The thing to do now is a fuel pressure test pump could be weak just a few pounds under the recamended pressure will do that weather its mechanical or electrical . Is there a filter in the carb. wear fuel fine hooks? If none of this is an issue at least you can eliminate fuel deliverly as the problem.

Apr 19, 2009 | 1989 Jeep Grand Wagoneer

1 Answer

1989 mercury Grand Marquis fuel system

The fuel pump relay is under the hood in the MAXI fuse box, it is a black box with a huge wiring bundle comming out of it.

Aug 19, 2008 | 1992 Mercury Grand Marquis

Not finding what you are looking for?
Cars & Trucks Logo

462 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts


Level 3 Expert

78238 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers


Level 3 Expert

5653 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides