Hey guys I'm new to the site, I'm actually here to see if anyone has insight on how to fix my wife's car. She has a 2001 Plymouth Neon, roughly 90,000 miles on it.

Problem: When idling the car shakes extremely bad whether in neutral or drive, especially at stop lights. The car has a misfire in cylinder 4.

Tried Solutions:
Replaced Spark Plugs
Replaced Spark Plug Wires
Replaced Motor Mounts, not transmission one yet
Checked for Intake Leaks- None Found
Checked Resistance on Fuel Injectors- Fine 13ohms
Replaced Ignition Coil- 1 year ago
Checked Resistance on Ignition Coil- Fine with Secondary check 13ohms roughly
Have used Seafoam and Lucas Injector cleaners with slight improvement, not in shaking but driving acceleration
Valve Cover Gasket Changed in case there was a leak
If wire 4 is removed when engine is on there is no change in sound of engine


Fixing it..... priceless

My next thought is to check the compression, I am beginning to wonder if it is an internal problem. Also a long time ago an EVAP Emisson problem was detected on the code reader and it hasn't returned.

So any ideas from mechanics or individuals who have built these suckers from the ground up I would really appreciate it. Thanks for your time guys.

 

compression check is a good idea

post here for more views
https://dodgeforum.com/forum/2nd-gen-neon-78/