It could be misfiring. It could be set to idle too low. The timing could be off. Check what your RPMs are when the car is idling- it should be 8,000.
The idle is automatic. If the speed is not corect then you have to fix the problem with the idle motor.
Idle is computer controlled, there is no adjustment screw.
it could be your EGR valve.
Check for a vacuum leak
maybe the valve timing is a little bit out
Due to the electronic fuel injection system in the 1997 Dodge Neon it is not possible to lower the idle speed. The engine control system computer adjusts the speed automatically.
Idle is computer controlled and is not adjustable. If idle speed is incorrect, you have a sensor or actuator issue.Idle is computer controlled and is not adjustable. If idle speed is incorrect, you have a sensor or actuator issue.
Check the idle, crankshaft and camshaft sensors.
Check the motor mounts.
Idle speed on a Dodge Neon is not adjustable. Idle is computer controlled with an airflow control motor on the throttle body.
At idle, 20 - 30 psi is adequate, 35 or so is very good.
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%.