94 Crown Vic LX tune up

[Joegoalie]

New to the board. First let me say I love my Crown and hate it's lust of gas. I'm getting 17.5 mpg and not a whole lot better on the highway. Anyway to get better gas milage? I've heard to get dual exhuast, cut off the bottom of the air filter box to expose the whole filter and even going as far as gutting the cats. Any suggestions? Should those work? Are there any other economically sound improvements to consider? Thanks

[ModMech]

Originally Posted by Joegoalie

New to the board. First let me say I love my Crown and hate it's lust of gas. I'm getting 17.5 mpg and not a whole lot better on the highway. Anyway to get better gas milage?

tire pressure and drag (road speed) play huge roles in economy. If you are heavy on the gas, mileage will be low.

I've heard to get dual exhuast,

That will NOT help.

...cut off the bottom of the air filter box to expose the whole filter

That will HURT power and economy as you will suck in HOT engine compartment air.

and even going as far as gutting the cats.

that will do nothing for you except be illegal.


Cleaning the MAF sensor and replacing the FRONT O2 sensors often results in an improvement. Be sure to "reset" the PCM by disconnecting the battery for 15 minutes afterwards.

[Joegoalie]

Hmm you sure on the daul exhaust and gutting cats not helping? That would increase air flow right adding power thusly letting you use less gas for same power and save gas right? Or am I totally wrong??? Btw I don't care about legality, I don't live anywhere close to CA and if I was to move there I could just get new ones. I suspected that guy was full of crap though about the cutting the air box... Didn't make much sense to me to suck up the hot engine air either. On the same matter though has anyone rigged a sort of cold air intake for a 94? Have pics? Very curious on this!

Cleaning the MAF sensor and replacing the FRONT O2 sensors often results in an improvement. Be sure to "reset" the PCM by disconnecting the battery for 15 minutes afterwards. <~~~ I'm illeterate when it comes to this stuff I have no idea what you mean . However I'm sure someone at Auto Zone, or somewhere, can help me.

My tire pressure should be good just had that all checked recently. And what do you mean heavy on gas? Do you mean Tank too full?? Do you think that a K&N filter would make a worthy contribution?

[Turbo_Cobra]

I have the regular K&N square filter in my 94 Crown Vic air box, noticed some improvement in performance.

[Joegoalie]

Holy cow! I'm not used to a furom that takes this long to respond . Anyway, I have already done the dirty deed... This is what I purchased... http://cgi.ebay.com/ebaymotors/ws/eB...tem=8003098120. Next some time in the future when I have the cash it will be time for dual exhuast . But, where do I go from there? What else can I do to squeeze out more power? Anyone know where to get a chip at? BTW I topped my car out at about 106 the other day. But, the car felt like it wanted to go faster but then would hesitate and slow again... Is there a way to disable that? Not, that I'd ever actually hit that top speed again.

[Joegoalie]

Well, I cleaned my MAF according to the insructions I found somwhere at this forum. Also, my intake arrived. Now I have another question. How or should I make some sort of heat sheilding? I kind of think at high speeds it wont matter because of the air flow in the engine compartment anyway, but at lower speeds is it going to make that big of a difference? Thanks

[way2old]

You got me confused here. Do you want better mileage, or more power?? It is extremely hard to have both. So, if you are looking for optimum mileage, stay as close to stock as possible. All sensors need to be checked, complete tune up, fuel filter, correct tire pressures, easy on throttle when driving. Most of the mileage issues are in the right foot of the driver. There are lots of performance modifications you can do, but performance usually equals lower mileage.

[Joegoalie]

Originally Posted by way2old

You got me confused here. Do you want better mileage, or more power?? It is extremely hard to have both. So, if you are looking for optimum mileage, stay as close to stock as possible. All sensors need to be checked, complete tune up, fuel filter, correct tire pressures, easy on throttle when driving. Most of the mileage issues are in the right foot of the driver. There are lots of performance modifications you can do, but performance usually equals lower mileage.

Yeah, well... I guess I want a mixture of both. I know it doesn't seem to work. But, I was under the impression, and I still am, that helping my car breath better will help with power and mpg. So, an intake and dual exhaust is logical right? Also, I don't think I have any sensor problems as I've been reading on this board and I've come to find that 17.5 mpg is about normal... However, I cleaned my MAF regardless. Am I totally whack about the engine breathing thing though? Other then that yes I wanted to stay stock. And you say to watch tire pressure. What about a different size tire? Say I up it to 16" instead of the stock 15"s? And I tend to be easy on the throttle. I know when I first got it I wasn't and I got about 13-14 mpg on that tank. But, what man isn't heavy on the throttle of their new toys?

[reekor]

I just got dual exhaust put on my 94 cv 3 months ago with flowmaster mufflers. A stock dual exhaust system will give you around 15 hp. With the single exhaust I found that with the pedal to the metal the car was choking and it would sound like a shopvac. The dual exhaust took care of that problem, however I did not notice the car to be better on gas. I do have a 92 GM with factory dual exhaust twice the mileage as my 94 cv and the gm is noticeably better on gas and noticeably lazier due to both cars having a different gear ratio in the rear end.

If you're looking to make the car go faster off the line you might want to try a set of 3:55 or 3:73 gears for that car. If it's better gas mileage that you're after try a set of 2:73 gears.

To avoid the speed governor find yourself an ECM out of a 94 CVPI.

Originally Posted by Joegoalie

Yeah, well... I guess I want a mixture of both. I know it doesn't seem to work. But, I was under the impression, and I still am, that helping my car breath better will help with power and mpg. So, an intake and dual exhaust is logical right? Also, I don't think I have any sensor problems as I've been reading on this board and I've come to find that 17.5 mpg is about normal... However, I cleaned my MAF regardless. Am I totally whack about the engine breathing thing though? Other then that yes I wanted to stay stock. And you say to watch tire pressure. What about a different size tire? Say I up it to 16" instead of the stock 15"s? And I tend to be easy on the throttle. I know when I first got it I wasn't and I got about 13-14 mpg on that tank. But, what man isn't heavy on the throttle of their new toys?

[Joegoalie]

Originally Posted by reekor

If you're looking to make the car go faster off the line you might want to try a set of 3:55 or 3:73 gears for that car. If it's better gas mileage that you're after try a set of 2:73 gears.

To avoid the speed governor find yourself an ECM out of a 94 CVPI.

Ok I have a stock LX what gear ratio do I have? And how would I change that? Also, where could I get a CVPI ECM? And a stupider question what is a ECM XD. I'm sorry I don't know a whole lot about cars I'm just learning.

[reekor]

There is no such thing as a stupid question. From one Vic to another you can't tell the gear ratio, since Ford uses different ones with different options, along with track-loc. The gears are located in the rear differential. This is not something that you want to try doing yourself, it takes a little know-how and a few special tools. You would also need to change the speed sensor gear in the transmission to match the gears or your speedo would be way off. THE ECM ( Electronic Control Module ) is computer that controls your motor and transmission. From time to time you can find used ECM's on Ebay, You would need one out of a 1993-1994 CV police car.

Want my advice? In this world of rice burners and oversize SUV’s any stock CV has enough power to pass and get around traffic, and it you have the need to drive fast enough for the limiter to shut you down there is something wrong. If you have a real need for speed sell the car and buy a Mustang, you can get all kinds of add-ons for them and they are nowhere as heavy as the CV. If it’s a sleeper that you are after, find yourself a totaled Mustang and do a drive-train transplant and from there the sky (cash lol) is the limit to what you can do. My 94 is stock other then the exhaust system (for a nice rumble), the charging system was upgraded due to my stereo and I lifted the rear of the car to fit wide tires in there for a retro hotrod look. Here’s a link: http://www.cardomain.com/ride/849925

Originally Posted by Joegoalie

Ok I have a stock LX what gear ratio do I have? And how would I change that? Also, where could I get a CVPI ECM? And a stupider question what is a ECM XD. I'm sorry I don't know a whole lot about cars I'm just learning.