Black Tailpipe Soot

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14-Nov-2004, 09:18 PM

sohcnotec

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Join Date: Oct 2004

Location: Milton

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Black Tailpipe Soot

I've searched the archives prior to posting this.
The prob is my 94 Civic has black soot that emits from the tailpipe and gets all over the rear bumper and tailpipe. It shoots out some black water sometimes when cold. The motor is a bone stock 1.5l, only an intake.

New parts within the last week are:

Spark plugs
Wires
O2 sensor
PCV Valve
Cap and rotor
The air filter is clean as well.

I've tried putting back the stock intake to see if this would make a difference, but no diff.
The car doesn't consume much oil for it's mileage (320k).
Otherwise it runs and starts excellent, but this is annoying.

Some older posts have suggested oil consumption or misfiring but I have none of those probs.
I'll try checking fuel pressure this week (40psi right?) and when the tank runs empty I'll try some Ultra 94.

Any other suggestions or has anyone had this problem before?
Coolant temp sensor, maybe?
Thanks

15-Nov-2004, 01:00 PM

spracingsports

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Location: Southern California

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catalytic converter

15-Nov-2004, 01:45 PM

imported_Cablerat

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Probably running rich.

Running rich causes black smoke out the tail.. (Unburnt fuel)

15-Nov-2004, 09:00 PM

j_limitz

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Join Date: Apr 2004

Posts: 1,640

yeah i have that problem as well....

what is running rich?

15-Nov-2004, 09:20 PM

imported_gatherer

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Location: on a race track

Posts: 17,846

Quote:

Originally posted by j_limitz
yeah i have that problem as well....

what is running rich?

the engine is running rich.... many reasons as to why...

bad O2 sensor .. O2 sensor signal shorted
stuckl injector
bad ECU
fuel pressure off the wall to high
fuel filter????

fuel pump????

MAP sensor signals fubarred?

lots of stuff can cause the ECU to dump more fuel.... engine running to hot will also cause it....

16-Nov-2004, 11:07 AM

QuiCK_TiME

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Location: Mac U

Posts: 671

car is running rich, my car spits unburnt fuel out at idle, makes a nice puddle for me on the driveway everytime

17-Nov-2004, 09:36 AM

bustedB18

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Posts: 36

pull ur spark plugs out and observe the colour....

17-Nov-2004, 12:06 PM

bbarbulo

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Quote:

Originally posted by QuiCK_TiME
car is running rich, my car spits unburnt fuel out at idle, makes a nice puddle for me on the driveway everytime

try to light that puddle on fire

haha... man the puddle is water vapour from your exhaust, it's not raw fuel

think about it... fuel evaporates even at room temp, right? now... think about how hot the engine gets... do you really think raw liquid fuel could make it all the way from your engine to the tailpipe w/o evaporating?

17-Nov-2004, 01:02 PM

QuiCK_TiME

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Join Date: Jul 2003

Location: Mac U

Posts: 671

Quote:

Originally posted by bbarbulo

try to light that puddle on fire

haha... man the puddle is water vapour from your exhaust, it's not raw fuel think about it... fuel evaporates even at room temp, right? now... think about how hot the engine gets... do you really think raw liquid fuel could make it all the way from your engine to the tailpipe w/o evaporating?

true that is