325i running rich

[Sambino]

Afternoon all.

My 325i is running rich. Not sure why as I have changed the brown and blue switches on top of thermostat. New thermo has been fitted.

Has new fuel pump and fuel pressure regulator. Normally smells really bad on start up and can smell the scent inside the car.

When very cold can be lumpy till it warms up.

Would greatful for some pointers. a‘aaaa

[Brianmoooore]

First of all, how do you know it's running rich? A smell of fuel in the exhaust is not an indicator.
An engine that's running lean fails to ignite some of the fuel, and that passes out of the exhaust pipe.
What colour are the plug tips?

[Sambino]

Not checked Brian. As fitted new plugs - even my neighbor was saying he could smell the car as I drove past him as he was walking up the road- cat? O2 sensor ?

[Brianmoooore]

cat? O2 sensor ?

Most E30s don't even have these! Does yours?
As I've said above, a smell of fuel is as likely to be an indication of lean running as it is of rich.
If you've changed the plugs, what were the old ones like?
If it's running rich enough to cause problems, new plugs will soon be black.

[Sambino]

Cheers Brian. So what are the likely culprits? Maybe I'm wrong about rich as at times is fast and other times not so. Still waiting on a guy here who I paid 2 weeks ago for air box and maf....... That's another story. He hasn't sent it and has my money a˜a

[bosers]

As Brian often rightly says, it's important not to change components willy nilly without proper testing. There are many variables that can affect running. You won't be able to pin point the problem without testing. It could be injectors, air leaks, air flow meter, Ecu, Ht leads, TPS, or a combination of all of the above plus many I've forgotten. You need to get basic and methodical and sort it that way.