Mitsubishi Eclipse 3G Club banner
1 - 20 of 20 Posts

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #1 ·
This may, or may not be a good question. I am fishing here. I got my GT back together in February. After fixing a bunch of emissions stuff, I had to run it a bit to reset the fuel trims before I could get it smogged. It passed, and I have been driving it. Then I decided I wanted to put my cold air intake back on it. Would there be any reason to do something with the fuel trims again seeing as it flows a lot more air ? Not sure if anything should or could be done. Anybody have any imput ? ...J.D.
Car Vehicle Hood Motor vehicle Automotive design
 

·
Registered
2005 Spyder GT
Joined
·
498 Posts
Just disconnect your battery for about ten minutes to reset the ECU, then take a drive on the highway for the ECU to relearn the correct trim levels for the CAI. I personally wouldn't worry about getting it "tuned" unless I was also changing out the headers and exhaust, along with the CAI. Getting it tuned just for the CAI is probably a waste of money...

or buy a performance chip from ebay!!! LOL
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #3 ·
I agree. Nothing to tune there. My thinking is just that being as there is more airflow the trims might need a bit of a "tweek". The computer should take care of it if I reset it. Thanks. ...J.D.
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #5 ·
More air to the MAF tells the ECU you need more fuel. I don't think there is going to be any BIG change, but there should be some difference in fuel trim settings. ...J.D.
 

·
Registered
2005 Spyder GT
Joined
·
498 Posts
I don't think the fuel trims will change. You'll be getting more air before the MAF, not after it, so the fuel trim won't have to adjust.
If what you say is true, then the MAF would be acting as a air "restrictor" rather than a "sensor."
I'm not really sure that a CAI is designed to increase air flow anyway, unless the filter material of the cone filter is more porous than the stock air filter. I think its more designed to simply lower the temperature of the air entering the TB.
 

·
Super Moderator
Joined
·
4,785 Posts
I'll leave this here....

While it was free and won't hurt, when CAI/WAI first came out Sam actually did pretty extensive testing namely looking at both the temperature of the incoming air and the amount of air coming in. Short story, WAI/CAI, cut vents, closed vents, dryer hose to enclosed filter, nothing made an appreciable difference worth spending a dime on.
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #9 ·
The MAF [for Mass Air Flow] measures the volume of air coming into the engine. This tells the ECU how much fuel to supply INITALLY. In the Eclipse the MAF also includes an air temp sensor which the ECU uses to calculate air density. That information is then modified by the readings coming from the O2 sensors. The O2's give the ECU "feedback" so it can correct the mixture if it needs to. ...J.D.
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #10 · (Edited)
The purpose of using a Cold Air Intake is just as the name implies, to route colder air to the engine. Colder air is denser allowing for more fuel to be supplied by the MAF. ...J.D.
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #11 · (Edited)
UPDATE: I've only run 24 miles since I restarted the fuel trims. I can tell it is changing but not enough miles yet. Cold idle has changed a bit, and it is playing around It's idle speed, but throttle responds seems to be improved already. Just bought $50 worth of fuel just now and it only got me 8.47 U.S. gallons, so I am not driving any more than I have to. I guess I'll have to wait a bit to see how much difference re-setting the trims will make. ...J.D.
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #12 ·
Back when I started this thread I had put my long tube intake back on and was less than impressed with how the car was running. It seemed a little "dead". I disconnected the battery so as to re-start the fuel trim process.. I have not had a much reason to drive it so it took a while to draw some conclusions. Fuel being at almost $6 a gallon right now has slowed my driving a bit too. Now I am seeing a marked improvement in throttle response. It took it a bit to readjust to the new air intake, but it takes a lot less throttle to get the job done. My conclusion is yes, I would recommend if you are putting on a cold air intake to reset the throttle trims. ...J.D.
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #13 ·
Sorry to drag this on more but had an interesting observation on this. I got the Spyder out yesterday. It is warm and sunny here. It was almost 90 deg, I had to go to a neighboring town to a doctor's appointment. The car has now settled down to a very even idle at about 700 rpm. The interesting part is when I first fixed the EGR problem and got it smogged it would smell very HOT under the hood after driving it a while. After re-setting the trims [50+miles later] the hot smell is now gone and the throttle response is "spot on". My THEORY is it was a bit lean after reconnecting the EGR, and adding the CAI. The re-setting the trims corrected that. Looks to me like the factory has these set up on a very thin margin mixture wise.
Just a theory mind you. ...J.D.
 

·
Registered
2005 Spyder GT
Joined
·
498 Posts
Sorry to drag this on more but had an interesting observation on this. I got the Spyder out yesterday. It is warm and sunny here. It was almost 90 deg, I had to go to a neighboring town to a doctor's appointment. The car has now settled down to a very even idle at about 700 rpm. The interesting part is when I first fixed the EGR problem and got it smogged it would smell very HOT under the hood after driving it a while. After re-setting the trims [50+miles later] the hot smell is now gone and the throttle response is "spot on". My THEORY is it was a bit lean after reconnecting the EGR, and adding the CAI. The re-setting the trims corrected that. Looks to me like the factory has these set up on a very thin margin mixture wise.
Just a theory mind you. ...J.D.
I have a WAI setup...well technically I just removed the filter box and replaced with big fat K&N cone filter and got rid of tubing by the radiator. I did not get a noticable increase in throttle response, just a louder engine, right after that mod, but I did notice a difference when I started to consistently use high octane 92+
Someday I'll get around to swapping the intake tubing that came in the kit and wrapping it with heat shield tape, then getting a heat shield shroud for the filter. Probably a waste of time, but should "LOOK" better, anyway!
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #16 ·
Probably does not do much just to change out the air box. Just more noise. Really need to draw air in from outside the engine room. Where I live the ambient air in the summer is well over 100deg.F in the daytime almost all summer long. Under hood temps get "out of sight". Someday when I am bored I'll tape a remote digital thermometer under the hood and put the meter in the driver's compartment. Would be interesting to see just how hot it gets. The 92 octane surely cannot hurt though. ...J.D.
 

·
Registered
2005 Spyder GT
Joined
·
498 Posts
Probably does not do much just to change out the air box. Just more noise. Really need to draw air in from outside the engine room. Where I live the ambient air in the summer is well over 100deg.F in the daytime almost all summer long. Under hood temps get "out of sight". Someday when I am bored I'll tape a remote digital thermometer under the hood and put the meter in the driver's compartment. Would be interesting to see just how hot it gets. The 92 octane surely cannot hurt though. ...J.D.
I remember the first thing I did when I moved to Las Vegas was put an oil cooler on my Harley and heavier oil in my Fiero GT, along with high temp batteries.
I predict that more 6G72 owners will be posting problems due to using low octane to try to save on gas, which would be a big mistake...
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #18 ·
I use only premium fuel. I have seen a high temp here of 117 a couple of years back. This spring I am changing to a semi-synthetic oil 20w-50. The car has 143,000+ on the clock, and runs solid. Not taking any chances with lubrication.
...J.D.
 

·
Super Moderator
2001 Spyder GT
Joined
·
1,262 Posts
Why would someone lower the octane rating recommended for their vehicle just to save a buck or two? There is a reason why the manufacturer sticks a sticker in the gas cap that says Premium Fule Only. They don't do it to make the gas station more money. Before I got my license back I let my friend use my car and he would use the lower octane. I added some octane boost to compensate for his mistake. You are far better off using the recommended fuel or paying the consequences down the road. I feel sorry for you fellows that have to use your car as a daily to get back and forth from work. As a retiree, I just drive less but will not compromise on fuel. After saying all of that I admit I run the shitty gas in my Dakota, my daily and winter beater but never in my pride and joy.
 

·
Registered
2001 Spyder GT. Koni adjustable shocks. cold air intake, ST sway bar.17X8.5 rims. LED headlights.
Joined
·
346 Posts
Discussion Starter · #20 ·
My 3g has had a busy life. It was originally leased to a rental company in Las Vegas new. I purchased it in 2005 and it became my commuter car. I tried using lower octane fuels a couple of times. Both the car and I have been retired since 2008. I "resurrected" it this year after 4 yrs. in storage to become my plaything. I never use anything but high octane fuel anymore. Lower octane does not improve fuel mileage for this high compression engine. It just makes it run like a dog because the ECM retards the timing when it detects pinging. ...J.D.
 
1 - 20 of 20 Posts
Top