I had a second generation 2003 Dodge Neon that had very long start times. It would crank for 5-10 seconds before it started.
After reading through the forums I found that Neon’s have a Pressure Regulator which is also a fuel filter that keeps the gas pressure in lines when the car is turned off.
When the pressure regulator/fuel filter goes bad the pressure in the lines does not hold and causes long start times.
There are other things that can cause long start times but for this Neon it was the pressure regulator that was the cause.
Here are the steps to replacing the Fuel Filter / Pressure Regulator.
I made a video at the bottom of the page for a visual walk through.
Keep in mind every Neon will have aged differently, with different weather, and had owners that aged them all differently.
For me living in the south west which is mostly desert there is less rust than a car in the South or by an ocean would have, and so on.
Here is the Fuel Filter / Pressure Regulator On Amazon
CUSTOM New Fuel Injection Pressure Regulator Fit 96-05 Dodge Neon 2.0L 03-05 Neon 2.4L 01-02 Chrysler Sebring 2.4L/2.7L Stratus 2.4L/2.7L 96-01 Plymouth Neon 2.0L
The pressure regulator is located beneath the passenger side of the car directly in front of the back tire.
Unplug the power clip.
The pressure regulator is then turned to the left (counter-clockwise) and pulled out.
A Blue clip will hold the gas line on that will need to be removed and placed on the new regulator. Push in the sides of the clip and the line should come off.
Put the Blue clip on the new regulator.
It is a good idea to wipe some oil on the rubber O-Rings so they seal good.
Install the regulator by turning it into place clock-wise. For me the tab pointed to the left when in.
Plug all the lines back in.
After it is all back together it is a good idea to prime the line. This is done since all the fuel has drained out of the line and there is no gas from the regulator to the engine.
To prime the line simply turn the key to the on position so the pump kicks on then wait 3-5 seconds and then do it again.
After doing this 3-5 times the car should start right up.
This is a basic over view on how to swap out the fuel filter / pressure regulator on a second gen Dodge Neon.
As always take it to a mechanic if you do not feel comfortable working on your car.
Every aged car will be different, one may have more rust while another may have had a rock come up underneath bending parts.
Here is a video for a visual walk through.