idle not right, may be running a little rich also.

[blackstangt]

I have a feling it's my oxygen sensors reading constant lean, but here's what's happening:
1. when I put the clutch in and coast it sits at about 1500 rpm, sometimes not steady at between 1200-1700 rpm
2. at idle it sits at 900 rpm or sometimes almost stalls and up to 1400 rpm
3. at about 1600-1800 rpm if i have my foot off the throttle in gear, it bucks until a different rpm, or until it touch the throttle(doesn't take much).
My Engine:
340 hp gt40 crate motor
typhoon intake
bbk 70 mm tb and egr spacer
24 lb injectors
vortec 73 mm 24 lb mass air
flowtech exhaust
k&n filter

 

[GoldenEye]

One idea, just make sure to check the 10 pin connectors behind the intake, and the wiring for shorts. Had simmiliar problem, solved when short was found back there.

 

[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.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/article...c-iv_codes.html

IF your car is an 88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 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 .

 

[blackstangt]

could it be the oxygen sensors?

 

[blackstangt]

or do you think i need a chip

 

[blackstangt]

its a 1990, and im going to just try the oxygen sensors unless someone has another idea

 

[DMAN302]

dump the codes..could very likely be vac leak..broken hard vac line, or dirty maf, or yes o2 sensors. Just do as stated above save the pain and get the codes.

 

[blackstangt]

im going to try the codes somehow, but could a disconnected/blocked off carbon canister and vac lines to the intake be the problem? or even though its mass air, it doesn't have the map/baro sensor to the intake, could that be it?

 

[nito88stang]

clean the IAC and check your TPS

 

[battyice]

im going to try the codes somehow, but could a disconnected/blocked off carbon canister and vac lines to the intake be the problem? or even though its mass air, it doesn't have the map/baro sensor to the intake, could that be it?

If one of the vaccum lines is unhooked and resulting in a vaccum leak, then yes, that may very well be your problem.

 

[jrichker]

im going to try the codes somehow, but could a disconnected/blocked off carbon canister and vac lines to the intake be the problem? or even though its mass air, it doesn't have the map/baro sensor to the intake, could that be it?

The bar/map sensor does not connect to the intake manifold on Mass Air cars. It vents to the open atmosphere.

 

[blackstangt]

it used to be hooked up with the old motor though

 

[Copperstang87]

I say clean out ur idle air control right by ur throttle body, if those r carboned up ur car will idle funny.