Running extremely rich

[MurdockSVT]

ok fellas, hook me up. My 93 is running extremely rich, im getting like 12mpg the car smells like fuel all the time, the idle hangs when i let the gas off. Its not the MAF because i just cleaned it.

so let the diagnosis begin.

symptoms:

strong smell of gas
poor fuel mileage
hanging revs when off the gas and approaching stop light
rough idle after it returns
poor cold starts and idle quality

thats it... ready set go!

 

[autoXr1]

What testing have you done? KOEO codes?

 

[MurdockSVT]

I have not had the opportunity to pull codes. I will do that tomorrow.

 

[triblk6spd]

please more on this. i have the exact same problems. btw how do i clean the maf without ruining it? how do i get the codes. i am new to this mustang thing.

 

[triblk6spd]

no more info?

 

[NCStang86]

It still could be the MAF. Cleanining it wouldn't tell u if was bad or not. Alot of things control the fuel like O2 sensors,TPS,ACT,MAF,Coolant temp sensor located in the heater tubes.U could even have a computer going bad.

 

[crazypete]

Well, this is almost _always_ a bad O2 sensor. They go bad all the time and the computer probably has a code 40/41(?) O2 sensor high/low logged. Disconnect the battery for 10 minutes, reattach then drive for 10-15 minutes then pull the codes again. Codes tend to cascade. Go for the item that is first in the intake chain (MAF if it is listed)

If this is not the case, it could be a leaking injector. I supposed doing the SEFI cylinder balance test will tell you which cylinder is at fault if so. Just wait till the codes are done transmitting, tap the gas for a few seconds, release and the car will begin a balance test and report to you (in voltmeter sweeps) the cylinders which are contributing less. A full rich cylinder will have poor combustion and wont be contributing as much to the idle as a good cylinder.

Is the smell of gas is actual gas smell or the rich exhuast smell?

You can pull codes with a voltmeter. All you have to do is find the harness in the enginebay and jump one wire. Here is a website that describes the procedure:

http://www.corral.net/20anngt/images/test.gif
http://www.corral.net/20anngt/eec.htm

have fun!

Pete

 

[autoXr1]

Any number of things can cause an overly rich condition. That said, the beauty of computer controlled engines is that they will often self-diagnose. Take the car to Autozone and have them hook up their scanner to the car. I believe they'll do it for free. I also believe they should have the code descriptions, so you don't have to research this data.

As is, all we can give you is a bunch of unusable internet conjecture.