Hello Everyone,

This is my first post and I hope someone will be able to help me. As my screen name states, I am a truck guy, but I also like cars. I have above average mechanical skills having rebuilt Ford 5.0 liter motors and restoring vehicles.

The problem...

My girlfriend has a 2000 Accord, 4-cylinder, ultra-low emissions engine. The car starts fine and after ~15-30 seconds, it begins to misfire. I get P301, P302, etc. All of the cylinders misfire randomly. This started happening after the vehicle sat in the driveway undriven for a couple of months. The misfires are so bad the car is not driveable.

So far this is what I have replaced:
NGK spark plugs
NGK spark plug wires
Cap
Rotor
EGR valve
Added fresh gas

I also visually checked the vacuum hoses and they look fine. I didn't notice any cracks in the vacuum hoses. I don't think the Idle Air Control valve is faulty because when I step on the accelerator pedal, the misfire gets worse. Why would the car run fine for a few seconds and then begin to run rough (misfire)? Does this sound like I could have a bad fuel pressure regulator? Any help would be greatly appreciated!

JR

 

Replaced PCV yesterday. It was clogged. Car runs slightly better, but it still misfires.