98 Ford Ranger Idle Issue

[mkluther]

Have a 98 Ford Ranger with 3.0 liter motor. The idle will stay at 1500 rpm until the vehicle comes to a complete stop. Replaced many parts and read hundreds of threads for the same problem. Does anyone know if this is a known electrical problem? It is driving me crazy.

Thanks

[phantom_smack]

Not to my knowledge,what all have you done?

[adrenochrome]

Is there a "check engine" light on? Could be a bad idle air bypass valve but you probably already replaced that.

[mkluther]

Okay - here's what I've done to fix the idle:

- new idle air bypass unit
- new pressure differential unit (fixed check engine light)
- new throttle position sensor
- new EGR valve
- two new O2 sensors (computer diagnostic indicated bad)
- 6 new fuel injectors
- clean throttle body inside and out.
- performed vacuum hose check - no vacuum leaks.
- New engine temperature sensor
- New spark plugs / wires
- New fuel Filter
- New accelerator cable (original was frayed)
- had computer diagnostics ran three times (have a friend with a unit) No faults found.

My personal opinion is the computer is telling the idle air bypass unit to keep the idle up like the old vacuum units did on carburators. The ABS system is telling the computer the wheels are moving but something's going wrong. No Engineer would design a car to idle high indefinitely until the car comes to a complete stop.

Put on your thinking caps and let me know. Thanks,

[phantom_smack]

Do you know what the tps voltage is?