Does any one know how to adjust the air fuel ratio on a 99 gst? I took it to a shop the other day and he said it seems to be running rich And that my be why my car smokes. Is that true can running rich cause smoke out the exhaust? Also My car only seem s to be smoking in the mouring or when it has been sitting for a while. any help would be great It's hard to get a car to look nice when it smokes.

 

What color is the smoke? Is it a black smoke? or blue?

 

before you listen to a shop, double check what they said. Pull out the spark plugs from cyl 1 and 4, just oppsit sides of the motor. If the plugs are black then ya your proly funning a bit rich. I dont think its a problem like sanguinius is hinting at. It it were leeking oil or water it would be a constant smoke, but because its only on warm up or after it been sitting a while its proly fuel/carbon. One way to fix it would to be getting a mbc and crank up the boost a 1LB or 2. Only do this if you have a aftermarket boost gauge. Other than that your going to have to get a piggy back emu, like a safc, which would proly be the cheapest and best way to go. But be carefull winter is comming and colder air is denser and will make you car lean out a bit. If you intrested in a mbc go to joepmbc.com There cheap as hell and have a lifetime warrenty.

 

or you could get a datalogger and see what your A/F ratio is.

 

all dsms run a little rich from the factory, but not enough to smoke, and if it is you need to find out why. and dont ajust the air fuel ratio if you are still running stock injectors unless you like buying new motors. the ecu knows how much fuel to inject already.

 

I beg to differ with slow420a. If you have worn valve guides then you will smoke lightly for a few minutes after starting the car but it will be a blueish color. Usually once the car warms up the expansion factor usually stops it but when you shut it off a little bit of oil will drip through to the cylinders. That's the only reason I asked the color. I wasn't hinting at a major problem only the minor problem of valve guides.

 

ahhh good point

 

yeah My check engine light turned on after it started to run rough. I pulled the codes and I got 2 codes about the MAS. One was about bearmetric temp and i for get the other one. The machanic was saying that the mas reading the air as -40F so that is why I am more than likely smoking. I just need to find one and install it.

 

Or it could be that. LOL but that's why I asked the color of the smoke. At least you got the easier of the 2 to fix.

 

I had the oxygen sensor go on mine a while back, and it blew smoke like you couldnt believe when you stepped on it... Could be something to keep in mind [&:]