Help, my 97 Explorer 4.0 misfires

[2000StreetRod]

Rapid rpm change

Your engine speed is fluctuating 40 rpm in about a second. Did you log the spark advance for the posted data log? Try disconnecting and connecting the crankshaft position sensor (CKP) a few times to clean the contacts. It's location exposes it to the elements (dirt, snow, rain, etc.). Check the condition of the wires attached to the connector for breaks or fraying.

 

[Arvika]

No, I did not log the spark advance, but I might be able to do that tomorrow.
I will also try cleaning the CKP connector.
Starting to get frustrated now... Just would like to put a match to it, and burn the thing!

 

[96eb96]

Are your injectors firing properly? Good fuel pressure?

 

[Arvika]

Are your injectors firing properly? Good fuel pressure?

That's to find out...
I'll do some more tests tomorrow.
The time here is 1 AM now, so I'll just have a couple of hours sleep first.

 

[2000StreetRod]

Comparison data

Here is some data from another forum member's stock SOHC:

At idle in park:
RPM: ~650
Timing Advance: 16-17
MAF flow rate: 4.6g/s

1500rpm in P
Timing adv: 20
MAF: 11.2g/s

3000rpm in P:
Timing adv: 20
MAF: 20.2g/s

 

[fox2,3]

misfiring explorer

what was the problem ? or did it just get a match?

That's to find out...
I'll do some more tests tomorrow.
The time here is 1 AM now, so I'll just have a couple of hours sleep first.