new MS3 running rich

[imac]

i finally picked up my MS3 a few days ago, and i've put about 150 miles on it since, but i've noticed that it's definitely running rich. the fuel economy average, according to the car's computer, is only 18 mpg. the first thing that tipped me off tho was the black carbon residue on my exhaust. i noticed that the exhaust tip was dirty and ran my finger around the inside of it and my finger was completely covered in carbon.

my question is did any of your cars do this? i had thought that maybe it was a break-in technique to keep the motor from running too hot and then the ECU would automatically lean the mixture when i hit 500 miles or so.

anybody know anything about this, or do you think i should run it back to the dealer and have them adjust the fuel mapping asap?

 

[ottawaP5]

yes this is normal, these cars run pretty rich. If I floor mine, I actually see black smoke through the back window.

 

[Super Unique]

PIG rich

 

[MS3077]

PIG rich

+1

Yeah at times when I punch it in 2nd gear I can see a cloud of black smoke coming from the exhaust I like it!

 

[SharkDiver]

A new intake will help with that and add some HP..But ya its normal.

 

[Boosted333]

Here is my a/f (and boost) before and after a Cobb SRI. Dashed line is stock, solid is Cobb'ed. Just to show where stock was on my MS3 and where it went after adding the intake.

 

[MS3077]

Boosted333- This is good info, thanks for posting!

 

[Boosted333]

Thanks. Here is the dyno chart that goes along with it if anyone is interested, so you can see the increase in HP and TQ. It was on a Dynapack, the numbers are high but the increase should be accurate.

 

[dkswim]

your computer is showing you 18 thats low that means its probably 15 mpg actual you might need to curb that lead foot... but yeah we are allways running rich 11-12 durring accelaration and 14.7 during idle and light throttle.

look at my quotes below.

 

[imac]

your computer is showing you 18 thats low that means its probably 15 mpg actual you might need to curb that lead foot... but yeah we are allways running rich 11-12 durring accelaration and 14.7 during idle and light throttle.

look at my quotes below.

i havent been getting on it much at all, still breaking it in. the reason the mileage was so low was because there were about 100 test drive miles on it from the dealer, and i hadnt reset the average mpg on the car's computer. i reset it tonight before i took a trip that was an easy 8 miles, and i was around 27 mpg, which seems a lot more reasonable.

i dont have a ton of carbon coming out, just stuff building up in the muffler tip, so i just wanted to make sure that it was normal for the car, which is apparently the case. a short ram or CAI is a good idea to lean it out a little, thanks shark. i'll prob wait till im around 2k miles before i throw one on thoe, just to make sure i dont do anything to screw it up during the break in.

 

[Boosted333]

Break it in hard....... and then change the oil soon.

 

[imac]

Break it in hard....... and then change the oil soon.

im still under the old school train of thought for breaking it in. im not babying it or anything, but im not taking it too hard out of first, tho i'll run it out to about 5000 rpm in 2nd - 4th once in a while. i figure if i vary the driving and let it stretch its legs out here and there, it should be just fine.

as far as the oil, i'll probably change it right at 2000 miles for the first, then again at 5000 and go synthetic from there out.

 

[Boosted333]

I basically find the biggest hill on the highway and load up the motor going up that hill in 5th or 6th. Try to let it rev out somewhat going up the hill, do that a few times, done. Then change the oil.

 

[matsuda]

Here is my a/f (and boost) before and after a Cobb SRI. Dashed line is stock, solid is Cobb'ed. Just to show where stock was on my MS3 and where it went after adding the intake.

What???

According to that graph, the A/F is leaner than stoich at ~5000 RPM.
You couldn't have been anywhere near WOT.

 

[Boosted333]

A/F is around 10.75:1 @ 5000 rpm.

 

[dkswim]

green line is AF and numbers are on the left, blue line is pressure whith its scale on the right. the leanest you see at wot is probably 11.7 and thats when it first offens up

 

[SPEED3TYPE2]

u a newb!..lol its normal for the speed dude