fuel problem......why to rich, why high idle

[bagel77]

HELP fuel problem......why to rich, why high idle

I have a 93 mustang I just did a motor and tranny (5 Speed) swap I put in a new mass air harness now it is running way to rich I mean it looks like a black smoke screen when I hit the gas. i put in new o2's today still no help. While checking the fuel pressure today (40psi at key on and about 32psi running) I realized that when I turn off the fuel pump (I have a cut off) at idle the car picks up about 1000 - 1200 RPMs and keeps running for about 35-36 seconds. is this normal?? I also found out that I can't get the car to idle down. The adjustment screw on throttle body did nothing. The car idles at 1500 RPMs so I ran at 3000-3400 rpms with the fuel pump off for that long. Any suggestions would be great.

 

[90mustangGT]

Have you checked for codes??? If so what are they? Vaccume leaks???

 

[jrichker]

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.