running too rich?

[atomic]

How can you tell and how easy is it to adjust?

I'm just suspecting cos there's a really strong petrol smell, esp when the engine's just started and the economy seems poorer than usual.

Thx

[PUR157]

One of the more obvious signs is the car spewing black smoke under hard acceleration

If your cars bum is covered in black soot very soon after a wash this is also a sign...

Sorry but this young 'un can't help you much more than that...

[Sean]

How can you tell and how easy is it to adjust?

I'm just suspecting cos there's a really strong petrol smell, esp when the engine's just started and the economy seems poorer than usual.

Thx

It's not easily or readily adjustable. Although if it is running rich something will be casing it to be that way, get that fixed and your problem is solved!

[StanTheMan]

but one way to do it....is Get your ECU Polarised.
or muck around with the spring in your AFM if your car is a NA6.....not possible on anything later

But both should be aproached with care & common sense. And like Sean suggested.....fix everything else first before you start mucking around with those bits.

[bruce]

Sure you're not having a bit of petrol leak into the boot problem (to cause the fumes) ?

[JBT]

Sounds more like a leak than rich running.

[atomic]

What are some of the things I should be \"fixing\" first?
(or checking to see if it needs fixing)

It's definitely not a fuel leakage.

Thx

[StanTheMan]

lets start with the type of Car you have

[StanTheMan]

what sort of economy are you getting
what type of driving are you doing.
eg short trip, long trips, city driving......so on.

first thing I get is when i'm reversing out.....is a whif of petrol. But its real cold atm & my trips are few & very short. Fuel econ is crap......but thats expected

[Boags]

Sounds like a bung O2 sensor to me.

[atomic]

lets start with the type of Car you have

Actually you've seen my car - yellow NA6, black rims....

what sort of economy are you getting
what type of driving are you doing.
eg short trip, long trips, city driving......so on.

first thing I get is when i'm reversing out.....is a whif of petrol. But its real cold atm & my trips are few & very short. Fuel econ is crap......but thats expected

just regular driving, 20+ min trips around syd suburbs, usually not too much traffic

Maybe it's normal then? No black marks around the exhaust/rear bumper but I definitely get a strong whiff of petrol.

I've just been noticing that I'm getting close to 10L/100km whereas before I used to get around 8L/100km...

[manga_blue]

Sounds very O2 sensor-ish to me. If it's 4-wire now just replace it, if it's a single wire then upgrade to 4-wire and it'll be much better from cold.

http://www.aus-cartalk.com/viewtopic.php?t=25609

http://mymiata.paladinmicro.com/Miata4-WireO2.htm

http://www.aus-cartalk.com/viewtopic.php?t=25688

... and maybe another 10 or 20 O2 sensor threads I have not seen as well.

[JBT]

......there's a really strong petrol smell, esp when the engine's just started and the economy seems poorer than usual.

You don't necessarily smell fuel when running rich. A "really strong petrol smell" is indicative of a leak.

What does the exhaust look like? Is it blowing plumes of black smoke?

[atomic]

not really.

Only when I really give it a decent caning... and even then, it's just a few times initially, then it clears up. I'm thinking that's more carbon build up?

I guess maybe it's O2 related then... ?

Definitely no leak in petrol

[SPy vs. SPy]

check for an exhaust leak around the headers/exhaust before it gets to the O2 sensor, won't take much of a leak to cause chaos with fuel consumption.