BP running rich?

[russian]

Couple of my teammates had a feeling that the car is running rich - no idea how they have figured this out. Since I have a wideband anyway, I have plugged it just to see what would be displayed - and it reports ~11 AFR while idling or low-revving, and this is still true when the engine warms up.

So far we have tried swapping the MAF but this did not change anything.

What else should I swap? How should i diagnose this?

Does timing affect this? Should I mess with my timing?

[creyes1994]

My 88 LX with the stock B3 carbureted motor is also running rich, and I'm trying to figure it out. I looked at the oxygen sensor because it wasn't connected, and it had black soot on it, along with the inside of my exhaust, and presumably my spark plugs. You might want to try looking at the condition of your spark plugs and oxygen sensor(s), and also check distributor timing with a timing light, unless of course you have a coilpack setup.

[Hot_Wheels]

send the injectors out for cleaning, or i think there are some how to's using a ultra sonic cleaner.

[eurotiva]

Timing will also effect you air fuel ratio

[Advancedynamix]

Timing will also effect you air fuel ratio

Definitely. If your ignition timing is too far retarded the car will have atomization issues and will pass more unburned fuel. There are two reasons for this. First, is the obvious retarded ignition timing not allowing enough time for proper burn, second is less obvious. Ignition timing also controls injector timing on these early F.I. systems, and if the injectors fire too early the fuel won't mix properly with the air. I saw all that carbon on the side of your car in TX. Looks cool in the fender flare like that, almost like a jet engine exhaust.
Often, the O2 sensor won't report unburned fuel, because it measures oxygen levels, not hydrocarbons, and you may still have decent combustion. This means that you may be dumping more fuel than you think. The best way to check for excess unburned fuel is with a 4 gas analyzer. look at your HC levels compared to your CO and O2. It will tell you a lot more than an 02 alone. You can also smell your oil. After 1000 miles, if your oil smells like there is gas in it (and your compression readings are fine) then you have a fuel atomization issue.

Another note. Never trust the marks on the accessory drive pulley on a Mazda engine. These things slip all the time. I've seen them clocked nearly 180 degrees out (that pulley also wobbled really bad). I time them with the little notch in the crank pulley (cam drive pulley). You just need an advance-able timing light to do it this way.