Hello everyone. Newbie here looking for some help. 2002 Ford Ranger XLT with a 4.0 and about 150,000 miles.
Couple of weeks ago, got the dreaded check engine light along with associated apparent miss especially at low idle. Code indicates a #4 misfire. (P0304). I have checked all the basics including fuel pressure, spark plugs (changed em), spark plug wires, (swapped to verify wire was good), ohmed out injector, checked MAF sensor, checked coil pack using a visual spark indicator attach to plug wire and verified against another cylinder, compression check (180). So I have decided to pull the injectors. That led to pulling the intake as I noticed a slight antifreeze drip near the front of the intake just above where the thermostat lives.
My current immediate issue is all the build up in the intake ports along with pulling the injectors has resulted in a lot of debris down on the intake valves. I was thinking about getting an air vac and trying to suck the junk out though not sure if this will work or will I need to pull the heads. I would also like to scrape all the carbon buildup off while in the process though I fear my only choice is to pull the heads.
I would also appreciate any advice on what my problem might be with the misfire. Looking for common known problems. Searches on the web leads one to all kinds of possibilities.
Appreciate any help!!