My 2000 xj keeps misfiring in 4 and 5 with a blinking check engine light. Only after I drive it for a while. I have a brand new head Injectors coil plugs need help.

 

To clarify, you put on a new head, new injectors, new coil, new plugs and are getting misfire codes after it warms up? How long after a cold start? If you shut down, wait a minute, and then restart, how long until it misfires.

Why did you change the head in the first place.. Did you do it or have a shop do it?

What specific brand parts and part numbers did you buy? What's the number on the spark plugs.

Have you pulled the plugs to see what they look like? If so, can you post pics?

 

What trouble codes are stored?

 

p0300 p0304 p0305

 

Might as well start with checking compression.

 

All cylinders where 150 - 153 compression

 

That suggests a closed loop issue, and the culprit there is often oxygen sensors.

If you've got no O2 codes, with your OBD tester can you get sensor data in graph form?

 

I'd also make sure the injector plugs didn't get switched (although in an intact harness I don't believe 5 will reach 4).

 

And get the noid lights.

 

no they just make it to there own location. Thank you. Trying to pass inspection

 

1)did it run like this before all the parts were replaced?

2) you might try moving injectors around to see if the misfire follows the injectors.

3)look for vacuum leaks(injectors/manifold)
4) look for funky injector wiring...breaks, insulation etc