djkyle25

after workin in my car the other day for a while i started her up and pulled her out, come to find in my garage a pretty big spot of like black dust, exhaust residue about the size of my exhaust pipes(they kind point down to ground at back) and the spots were on both, sides, it was just a pretty dry dust, but im wanderin if this is bad at all? wut is it, and wut causes it

1SLO6

iTrader: (8)

Fuel............causes it...

borninatransam

iTrader: (4)

carbon build up. have you add any injector cleaner in it? even if you havent its carbon being blown out. excess gas, lack of air and what not can cause it to build up on the tops of the pistons and in the exhaust itself. if its gettin blown out its actually not a bad thing its just clearin it out. but add some sea foam to your gas and ive heard of some people mixing it in with the oil too but im not so sure how that works. stuff works pretty good though.

the_merv

iTrader: (88)

Believe it or not, it is actually a little bit of oil in with it. All Chevy's burn a little oil when they are cold. Mine does it. It runs a little rich when it starts also, that is part of it.

MOE_TAWS6

iTrader: (16)

My car does that too....but it also doesn't pull right? Oil also spits out the exhaust because there is oil marks on my back bumper???? why does it do that...

the_merv

iTrader: (88)

I have that when it is cold. All Chevy's do it, it is just cold, and all the seals haven't expanded yet in the engine. When it warms up, it's fine. Mine has black stuff all over it when I drive it too, I figure it is soot, cause oil has a different feel, and I like the throttle.....

borninatransam

iTrader: (4)

if your bumper is covered in black stuff i hate to tell you thats not oil. That would be your car running rich and burning more fuel than is necessary. you can have bad o2 sensors or your intake mite need cleaning. and its not right to say all lt1s spit oil. they dont all spit oil if yours does then get it checked out.

Dragframe

iTrader: (14)

mine dont spit any oil...

its cuz your car is running rich.

The LT1 That Could

iTrader: (3)

my turbo fox would leave black stains in my driveway, and trailer on start-up.....it had a PIG fuggin rich tune in it.....and that sounds like what your's is doing....too mas fuel!

MOE_TAWS6

iTrader: (16)

your right, it is fuel, not oil. But its not my O2's cuz i changed them and they went bad again because its running really rich. What can it be? My fuel injectors? Regulator? Or do i just need to use Seafoam and clean it all up?? The thing that is throwing me off is that it hesitates alot, and wont pull right....

borninatransam

iTrader: (4)

take it to a shop that can let you use a wideband and air/fuel ratio meter and figure how much your off. then once youve done that get them to calibrate it back as close to 13 as possible. the closer to 13 you are with a naturally aspirated motor the closer you are to optimal air/fuel mix. if you let them tune it like this you wont only see gains back in your gas mileage but also in the performance department. good luck

the_merv

iTrader: (88)

Mine is tuned to run a little rich, so I know it is gas. As I mentioned earlier, I know it is soot, cause oil has a different feel, and wouldn't make it that far out of the exhaust system. Your Mass Air Flow Sensor tells the car how much fuel to put in by the amount of air, and the O2 sensors tell weather it is running rich or lean. Could be the MAF sensor throwing it off.....

MOE_TAWS6

iTrader: (16)

so you dont think it could be the fuel injectors?? or the fuel pressure regulator?

the_merv

iTrader: (88)

If the Injectors were clogged, they would be restricted. Could be the regulator, putting in too much fuel.

MOE_TAWS6

iTrader: (16)

I took off the fuel rail, but left the fuel lines plugged up to it from the back, and put it in accessory like 3 times to build pressure in the fuel rails, and none of my injectors leaked. Is there anyway i can tell if they are clogged?

the_merv

iTrader: (88)

The engine will be lagging. Could be it, they are clogged, and the car tells it to send alot for the throttle you want, and it runs little rich cause there is more air coming in than normal.