Misfire Cylinder 3 P0300

[Schurkey]

Seems unlikely, since the cam sensor doesn't trigger sparks in the first place.

Plug wire? Fouled plug?

 

[jce98]

Seems unlikely, since the cam sensor doesn't trigger sparks in the first place.

Plug wire? Fouled plug?

New plugs, swapped wires.

I have a fresh plug in the box, and will try another wire. I would not think the new AC Delco cap would be bad, I may order another and try it.

 

[Schurkey]

What is the cranking compression pressure in that cylinder compared to the rest?

Fuel injection not spraying into #3 port? What are your O2 sensor readings for that bank?

Cam not opening the #3 intake valve?

 

[jce98]

What is the cranking compression pressure in that cylinder compared to the rest?

Fuel injection not spraying into #3 port? What are your O2 sensor readings for that bank?

Cam not opening the #3 intake valve?

Compression within 5% of all other cylinders. Cheapo hand held so I do not get a reading on the 02 sensor, just misfire cylinder 3. If the intake valve was not opening, it would affect the compression, correct? Since it is within 5% I ruled that out.

 

[Schurkey]

Spark tester in, no spark.

Does it show spark on the other cylinders that do run?

What spark tester are you using?

Replaced new cap with new AC Delco, same issue.

You've replaced the cap multiple times. You've replaced the plug wires and the spark plugs. I don't remember you saying you've replaced the rotor--but that shouldn't cause one cylinder to have no spark.

Misfire 3

You're getting a P0303 code? Or you're seeing misfire counts for #3?

Is the cam/crank sensor signal synchronization correct?

If the intake valve was not opening, it would affect the compression, correct? Since it is within 5% I ruled that out.

Yes, that's correct.

 

[jce98]

Does it show spark on the other cylinders that do run?

What spark tester are you using?


You've replaced the cap multiple times. You've replaced the plug wires and the spark plugs. I don't remember you saying you've replaced the rotor--but that shouldn't cause one cylinder to have no spark.


You're getting a P0303 code? Or you're seeing misfire counts for #3?

Is the cam/crank sensor signal synchronization correct?


Yes, that's correct.

Yes rotor replaced. But I have not synch the cam/crank sensor signals.

 

[jce98]

Yes rotor replaced. But I have not synch the cam/crank sensor signals.

I don't have a scanner that will allow me to see the signal to synch. But any reason I can't us my timing light to see where I am at?

 

[Schurkey]

I don't have a scanner that will allow me to see the signal to synch. But any reason I can't us my timing light to see where I am at?

Yes. You can turn the distributor all day, and twice on weekends and not affect the ignition timing. The timing light is useless for getting the cam sensor and crank sensor signals aligned.

Some folks claim they can get close enough by cutting holes in a sacrificial distributor cap, and adjusting the distributor for shortest spark arc between the rotor tip and the cap terminals at 1100 rpm. I've never done this.

 

[jce98]

Yes. You can turn the distributor all day, and twice on weekends and not affect the ignition timing. The timing light is useless for getting the cam sensor and crank sensor signals aligned.

Some folks claim they can get close enough by cutting holes in a sacrificial distributor cap, and adjusting the distributor for shortest spark arc between the rotor tip and the cap terminals at 1100 rpm. I've never done this.

Not trying to get them aligned a this point. Just curious if the light will show what timing is currently.

 

[Schurkey]

The timing light will show the timing advance. Timing advance is controlled by the ECM and the crank sensor, NOT the distributor.

Unless you've messed with the crank sensor, or played games with the computer tune, the timing advance will be whatever it was before you pulled the distributor.