Just purchased a 93 2.2lt auto EFI sedan in pretty good condition. I have an issue though. The idle and slightly above is erratic and it blows heavy fuel smoke out the exhaust.
If you rev the car a few times the fuel smoke clears but continues as does the erratic idle, soon after the engine returns to idle. This happens in gear and out, aircon on and off
On the road the engine runs well with no misses.
Could this be an Air flow meter issue or am I completely off base?
Any assistance is appreciated as the god of war and finance wants her car on the road Now!

 

You can smell the fuel in the exhaust as opposed to perhaps oil smoke?

When does the problem occur?

Cold starts after sitting awhile? Does the problem still exist after the engine has warmed up or when idling after driving?

Has the MPG dropped?

 

Yes definitely fuel smoke (black and sooty as coal).
It does it cold or hot but it does ease very slightly when the engine warms up.
Mpg have decreased considerably.
It is as if the engine is getting the same amount fuel at idle as it would driving.
I checked and cleaned all sensor wiring plugs I could find to no avail.

 

A few things to check:

Determine if the engine fuel system has a cold start injector. This is a single fuel injector that when engine is cold injects extra fuel into the intake manifold. The injector is linked to a coolant temp sensor and on a timer to only work when the coolant is cold and then for a timed amount. The injector could not be turning off or is stuck open.

If the engine does not have an injector it has coolant temp sensor that tells the computer to increase fuel when the engine is cold. The sensor can fail causing the computer to keep the injectors running rich.

A fuel injector for an engine cylinder could be stuck open.

Although unlikely check the engine air intake filter for plugging or perhaps a rodent building a nest in the filter air intake tube.

The fuel pressure regulator could be stuck closed resulting in higher fuel pressure at the injectors.

Make sure the ign system is operating correctly having a hot spark which should be able to gap 1/2 inch of air.

The AutoZone website may have trouble shooting and test data in the sites vehicle repair guide section for this year/model of car.

 

Thanks Joey I will try all these and let you know how I go. They make good sense.
Thanks
Chris

 

UPDATE: Thanks for your help joey
The entire problem was as simple as the vacuum hose from the inlet manifold to the sensor on the firewall had fallen off. Now runs as smooth as glass!

 

Great!