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Ford Crown Victoria/Mercury Grand Marquis Modifications



  • marsha7marsha7 Posts: 3,661
    Pardon my ignorance, but who did the flashing of the computer, how is it done, and just how does it "improve" the HP and performance??? can't change the compression or the internal engineering of th enginbe, so how does performance improve???...thanks...
  • joe110joe110 Posts: 19
    You are not being ignorant. Every car since the 90's are controlled by an ECM. Lets just use Ford for obvious reasons. I was told by SCT that our computers are compatible in more than one car. Its just tuned by the factory with a factory setting. For Ex- my computer can be used in a Excursion or a Lincoln LS. It just needs to be programmed by the factory. The rest you should be able to figure it out. Sure, a bigger cam or higher compression can increase the HP, but you should still tune the ECM to get all you can out of the engine. As far as flashing, you have to buy the flash device. It may be used or new. Mine was new at 425 bucks. Go to He sells new and used Flash devices. Or buy a Fast ford and Mustang mag. Look for flash devices in the mag. There are all kinds. I just plug SCT because I was referred by a Mustang user and tried it. I spoke to him last week and his brother works for a ford dealer. He got a used ECM and was playing with the programs. He was giving it to my buddy with the mustang to try out. Good luck.
  • turbo301turbo301 Posts: 73
    "Flashing", or reprogramming, the car's engine control computer adjusts things that are vacuum or mechanically operated in older cars: things like the timing, fuel/air mixture, idle speed, etc. are all adjustable, and all affect engine performance, life and fuel economy. Different vehicles and vehicle types benefit from different values for the various parameters, but using a common, programmable computer in multiple vehicles helps keep the cost down :).
  • abfischabfisch Posts: 591
    Have any of you changed the shocks to high performance shocks or changed the bushing to PU??/ Interested in buying a used CV and working on it myself, and wondering if anyone in this forum has done this. I have done this on my 02 Toyota Avalon with dramatic results.

  • rhill7rhill7 Posts: 3
    I just bought a left over 2006 GM with the handling, 3.27 rear axle, and dual exhaust package. I am happy with the power, but I would like to change how the transmission shifts and locks up. On my last car with OBDI, I was able to change the start in second gear so that with the shift lever in "2", it would start in first and then shift to second and then stay in second until I moved the shift lever to "D". I was also able to delay the shift to Overdrive and the convertor lockup to what I thought were acceptable speeds to avoid lugging the engine. I know that I can try to train my wife to use the "Overdrive Off" button in the column shift lever, but I'd like to avoid that if possible by reprogramming the transmission shift points.

    Does anyone know who sells a program for editing the transmission shift points and lockup points? Or is that available commercially for this car? I'd like to do my own programming if possible so that I can make adjustments until I get it where I want it without having to send a computer back to a tuning person several times.

    Or, what tuning persons work on our cars?

    Thanks in advance. :) RHill
  • rhill7rhill7 Posts: 3
    The Electronic Control Module (ECM or "Computer") typically has a program with instructions like "If the throttle position sensor is greater than X% and the manifold pressure is greater than P, then set ignition advance to A and the fuel flow to F". The values of X, P, A, and F are found in tables which can be edited. Editing the tables can make use of premium fuel and provide more power if you decide to use premium fuel. Editing the shift point tables can also make the car perform more aggressively by keeping the transmission in a lower gear for longer. Other significant improvements to the car's performance will probably involve the traditional increase intake airflow and exhaust flow and cubic inches. Or increase airflow by supercharging and fuel energy with nitrous, etc. Most modifications will involve computer table modifications to get the most out of them.

    To modify the computer tables, typically you copy the program/tables from your car to a laptop or destop computer, edit the tables, and then load them back into your car's computer "Flash the computer".

    For what it's worth and your mileage may vary. :)
  • Our 1998 Grand Marquis 4.6 liter V8 has a small crack on top of intake where the thermos goes. Apparently it is plastic and to buy the part is supposed to be over $200. Is there a way to repair the small crack? Husband needs advice.
  • euphoniumeuphonium Great Northwest, West of the Cascades.Posts: 3,305
    Check with dealer. That may be the intake manifold that has a factory recall order.
  • I have a 1999 Ford Crown Victoria and was wondering if the gauge cluster of a newer model crown victoria such as the 2006 with the tachometer would work in the 1999.

    Thanks for helping, if you can. :confuse:
  • royfroyf Posts: 1
    Hi Joe: I own a 04 CV Sport that came with dual exhaust. Each bank on your engine has a cat before it goes into a single pipe. I owned an 04 Cv with a single exhaust & had duals put on it.No problems at all & you will see a marked increase in performance with the duals.
  • My manifold is also cracked. Looking for recall info for it but cant find it. Also when i went to the dealer they said that it was past the 7 year warranty period and even if there was a recall they don't fix it. I think that is bull(*&^. Any other advice or stories about intake manifolds?
  • hyphyhyphy Posts: 2
    yes i know its silly. but what mods do i have to do to 97 vic to put these rims on it. spacers? cut wheel well?
  • euphoniumeuphonium Great Northwest, West of the Cascades.Posts: 3,305
    Don't know, but submit a photo when installed. :)
  • I have an 84 crown vic 5.0 throttle boddied carb. I just can't seem to get it to idle right. it either idles high or too low and when it idles low it surges. Iv'e replaced dist cap,plugs,upgraded wires and hotter coil. I've checked for bad vacuum lines. Any ideas? Is there any way to bypass the eec-iv computer and run a regular carb? :confuse:
  • dj7tryppdj7trypp Posts: 3
    Anyone know how to switch the computer from a manifold air-pressure sensor to a mass air-flow? Do I have to replace the entire induction system? If so, what are some good aftermarket choices?

    Also, the engine likes to cut out when I go around corners... I can''t even find anybody that's had the same problem.
  • ts128ts128 Posts: 1
    My Grand Marquis has been doing some strange things lately, it all started late one night when my daughter went out to get something out of the back seat, when she opened the left rear door the car began to turn over like it wanted to start, then it stopped, the next time it did this was when we were driving it, it started grinding like crazy, so the first thing we thought was to replace the starter, didn't help, next was it went to FOMO where they said it was a loose wire under the dash, it didn't happen again for two weeks and then it started doing it even worse, so I inspected the steering column for wires rubbing or loose, found nothing, checked the ignition switch and all looks to be good so I moved on to the starter relay and changed it. I'm hoping this fixes it but just wanted to see if anyone else with one of these cars has experience this.
    Thanks, Tim
  • i have a 98 mercury grand marquise with only has a v-8 4.6 engine.i would like to get at least 300hp or more without ripping my engine completely down. would any one have any suggestions?
  • euphoniumeuphonium Great Northwest, West of the Cascades.Posts: 3,305
    Before starting engine modifications, find out if the on board computer is compatible with the proposed changes. I learned a long time ago that should be checked out first when a Crower camshaft replaced the factory part. The computer would not let the new cam do its grind.
  • yes my computer is there anyway i can gain horse power with out tiering down my motor? i'm hpoing to gain at least 150-200hp before april,thats when lebanon valley speedway opens again.ty
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