1996 t bird 4.6l idles up and down - 1996 Ford Thunderbird LX

It's normally going to idle faster when cold, but you can change the idle speed down with a screwdriver at the throttle engine speed screw.

It likely has EFI (electronic fuel injection) and an idle air control valve that regulate idle speed. They can get gummed and fail to have a fast idle when cold, or get stuck the other way, and have a too fast idle all the or regularly take its time slowing down after you take your foot off the gas. An engine temp sensor can also cause a lingering high idle if it reports the engine as still being cold after warm up.

No Genie in Bottle -- is manufacture recommended or
will FIX anything --common sense,will just take your money

Clean out what specificly, I ask,on a 15 year old vehicle ?

Diagnose & resolve the issues

Gas Filter clogged completely,not likely, but happens

Fuel Pressure Okey--put a gauge on it & road test

Fuel Pump may be shot & not much pressure under a load

Exhaust Converter was TESTED -- HOW?
If it is 15 years old replace it,YOURSELF

TEST TPS Sensor Voltages

EGR Valve ?

You diagnose based on high vacuum signals &
high load conditions,there you add Ignition Issues

Check ford recalls, they had a recall for the intake manifold on the 1996 t-birds. Ford replaced no charge.

• Dirty air filter or bird nest in the air intake
• Broken vacuum hose or fitting
• Worn plugs or bad wires (will run rough; exhaust may smell dirty or have raw gas odor).
• Clogged fuel injector or fuel filter; failing fuel pump (will also run poorly at high power demand)
  
• Bad throttle position sensor or dirty throttle body - inspect any idle air bypass channels.
  
• Bad or misadjusted idle air solenoid (I'm not sure if it's used on this model; you'll have to check to see what engine you have.)

These are the first places to look. If the Check Engine light is on, getting a diagnostic readout may save some time in your search for the problem.

im having the same problem w my 97 bird... lopey or rough idle. no luck yet changed or tested many sensors already... if you have any tips let me know and ill do the same, [email protected] Thanks

Do you have a check engine light on? First thing I would do is unplug the IAC motor when the engine is warm. If the idle speed doesn't change you have a vacuum leak or a bad IAC motor. If the idle speed goes down you might have a bad TPS or IAC

you should not mess with idle screw, you are changing tps values,computer controls idle,check for vacum leaks,may be a hose or intake gasket.

i have a 94 bird did the same thing.
the problem is the mass air flow sensor
they are a little expensive because they sell
the whole piece as an assembly.
if you go to a junkyard with tamper proof torx head drivers you can take just the sensor off the metal housing, be careful there are two fragile wires visible when you take the sensor out of the housing. (they resemble a light bulb filament) if either oh the two are broken do not put it in your car. Please rank my answer as I am new here Thanks,Chris
[email protected]

more info ,or service it