Rapidly fluctuating idle revs in a 1994 Dodge Colt can be caused by several issues. Common culprits include a vacuum leak, a malfunctioning idle air control valve, or a dirty throttle body. Additionally, problems with the fuel system, such as a clogged fuel filter or failing fuel pump, could also contribute to this behavior. It's advisable to conduct a thorough inspection and diagnostic to identify the root cause.
Probaby a sensor.
It could be the throttle position sensor or the idle air control valve.
the Vaccume Brake Booster is bad.
Idle speed on a Dodge Neon is not adjustable. Idle is computer controlled with an airflow control motor on the throttle body.
The dodge neon has an optimum idle speed like any other car. The Dodge Neon's optimum idle speed at rest is between 12.9% and 13.3%.
"How do you move the idle tensioner for a 1998 3 litre dodge?"
it's just a bad ajusting of a carburetor, you can ajust it on the top of the carburetor by turning a bolt for put the idle more high
Idle speeds can vary from 500 to 1200 rpm
Your idle air sensor is bad.
The proper idle speed for a Dodge with a 318 cubic inch engine about 475 to 500 RPMs. Any idle below that will cause stalling.
try replacing the idol air control motor.
The idle is automatic. If the speed is not corect then you have to fix the problem with the idle motor.