New Filter and Holes... MPG DROPPED?

[Ray]

Three weeks ago I put a new K&N in my '94 Sport and drilled about a dozen 5/8" holes in the air box. I also cleaned out the Mass Air Sensor at that time (Sprayed w/ Gumout and Canned Air). I ran it like that for a few days until I read about needing to disconnect the computer for the mods to give full potential. Well, rather than disconnect the negative terminal and lose all the time I've put into naming things on my head unit, I took off the passenger kick panel and removed the computer completely for a few minutes. Now that I've been running for the past two and a half weeks with these mods, I've been able to check MPG and have discovered that it's dropped from 14 MPG to about 10. I still use the same driving technique (Coasting down hills, up to lights, taking off at about 2000 RPM), and I thought that these mods should have increased MPG, or at least kept it the same. Anyone have any ideas on what could be causing this? Does removing the computer not have the same effect as disconnecting the negative terminal? Could cleaning the sensor have something to do with it? It's a '94 Sport with 78K miles on it, bought it used about 9 months ago, and not sure of exactly what has been/needs to be replaced.
Any help will be greatly appreciated.

 

[TEX]

Removing the computer while the battery is connected can totally fry it. Fortunately, it didn't damage the computer in your case. Disconnecting the battery cable is no big deal. You just have to spend a few seconds re-programming your radio. It's a very bad idea to pull the computer out with the battery still connected because it could short the whole thing out. Since the vehicle still works, you're OK though.
As far as your problem is concerned, I've heard that carb cleaner can damage the MAF sensors. Electrical contact cleaner or special MAF cleaner is the only thing that I've heard won't damage the sensor itself, but I don't know this first-hand. I've just been told be a Ford rep and have seen it posted a number of times on message boards. Perhaps the spray damaged the sensor wires somehow?
It's only an idea.

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Have A Good One!
Chris Scott
chris@smartyparts.com
www.smartyparts.com

 

[Kyle K.]

Hey i understand your dilema losing 4 mpg is a big deal but dude you had problems before this. You should definitely be getting better than 14 mpg. Some of these guys ave reported getting 350-400 miles on a tank.

Let us know if you find the problem.

dodger

 

[Kris Guilbeaux]

Your Gasmilage is not good at all my 92 Navajo 5-speed gets about 18-20mpg. Things that can cause bad gasmileage are things like a bad O2 sensor, bad fuel presure regulator, or even bad spark plugs. What type of CD player do you have my sony keeps the names of CDs even if the battery is disconnected.

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Kris Guilbeaux
-- Dead Link Removed



[This message has been edited by Kris Guilbeaux (edited 12-22-1999).]

 

[DocMorro]

I am going to try this also. Can somebody explain how to do this the right way.
Beginning from disconnecting the battery.

Thanks,

 

[S.Matsushige]

Doc-whenever doing any changes to your engine such as plug, plug wire, air filter etc. its better to disconnect the negative battery cable so it'll reset your onboard computer. It'll take a few trips for your computer to relearn your driving habits and make adjustments with the new mods. When cleaning your throttle body, look for cleaners that are oxygen sensor safe.