2002 Ranger 4.0 DOHC #4 misfire help
Good evening all,
Looking for some help on what direction to go. I used to work on automobiles in the days when electronic ignitions were just coming out. Gave that up to work on aircraft. After a few recent bad experiences with the local garages I have decided I will fully maintain my own.
My 2002 Ford Ranger recently kicked a P0304 code along with a noticeable miss from idle and during moderate acceleration. I used a simple reader to get the code. After some internet investigation I decided to change the 3 left hand side plugs and also swapped plug wires. I then used a spark tester that only gives a visual that the cylinder was firing. I compared it to another cylinder. Checked compression which was around 175, (comparable to adjacent cylinder.) Followed this up with replacing the 6 intake seals, cleaned and tested injectors, swapped injector 4 with another injector, cleaned all the carbon out of the intake which was a result of the dreaded pvc elbow that had cracked previously. I had taped up the elbow to get me by and forgot about which ended up collapsing. In the process of cleaning the intake out I decided to pull the valve cover and found the pvc check valve somewhat plugged and cleaned that as well. Through all this I had what I felt was quite a bit of oil present in the intake. i also cleaned the EGR up as well. After the second drive the code kicked again. So I went and bought an advanced code reader. Here is the FF info given:
Fuel Sys Closed
So then I decided to take some readings at idle:
ABSLT TPS 19.6
IGN Adv 15.5
OBDII STAT CA
As the engine warmed up several of these variables changed such as 02 information. I can also graph certain items though am still trying to wrap my hands around exactly what I am doing. I am guessing my bank trims are out of whack on the one side. I am in the process of studying and trying to get a better understanding. Any help or further diagnosis requests is appreciated.