Okay here is the situation...
94 B18B1 - mileage unknown
My rear bumper looks like this...

But the plugs are white indicating that its running lean...

I did all the tune up stuff (plugs,wires,cap,rotor,etc...) and a compression test, results were: 165, 170, 170, 175

I was thinking that maybe the timing belt was off a little bit, but I havent had the time to take it apart to look. Any suggestions on what the problem is, I am sick of having to wash this crap off my bumper daily...

 

It actually doesn't look all that bad maybe a little rich, but not much. The big problem is how far the tip sticks in to your bumper. IF it is too close you will get a little carbon build up there.

 

plugs look great too me maybe a tad rich but id say there ok, check to see if your burning oil

 

That's running rich. Your spark plugs would have more white on it.

 

The black crap on the bumper is usually worse... It covers the whole bumper sometimes and if I never washed it off it would completely go black... I know it burns oil, I usually have to put a liter in every time i fill up, not to mention that it get horrible gas mileage... anyone else have some input...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rtype16 &raquo;</TD></TR><TR><TD CLASS="quote">The big problem is how far the tip sticks in to your bumper. IF it is too close you will get a little carbon build up there.</TD></TR></TABLE>
I know that this isnt the problem cause the motor that I had in the car previously never left any signs of carbon buildup...

 

well if you really wanna break it down oil is made of the same stuff gasoline is which are hydro carbons so when burned it's essentially gonna have that same carbon build up look i would say thats from your oil burning problem!

 

but doesn't oil burn up as blue smoke, and the black carbon stuff on the back of my bumper is fuel that didnt get burned up in the combustion chamber?

 

oil doesnt always burn blue most of the time yes but not all of the time and in the end with deposits it all comes out black. from your plugs id say your running fine and bruning some oil maybe a lil bit rich nothing to be concerned with

 

your plugs only show how they were running in terms of A/F, at the last point they were fired.

So if you pulled them after idling, they will show you the a/f at idle.

If you want to know high RPM wise, you will have to do a high rpm run and shut the engine down right at redline. Coast to a stop, then pull the plugs.

 

I will try that out thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eLusive ek4 &raquo;</TD></TR><TR><TD CLASS="quote">well if you really wanna break it down oil is made of the same stuff gasoline is which are hydro carbons so when burned it's essentially gonna have that same carbon build up look i would say thats from your oil burning problem!</TD></TR></TABLE>

 

Just for an update... I put an O2 sensor in the car yesterday and there is alot less black stuff on the bumper... I still think that it is running rich...