3.0si cylinder #4 misfire

mouncer · #1 03-03-2016, 10:41 AM

Hey guys, looking for a little advice. Have been having a misfire on cylinder #4, it started out only occuring every once in a while, and progressively got worse. When it first started out, it would only happen when I wanted to accelerate quickly and the car would hesistate/jerk, but would go away once I let off the gas pedal. It has progressively gotten worse from that point. Occasionally would occur on a cold start but turning off the ignition and restarting the vehicle would fix it. Now not so lucky. I figured at 80K miles I was due for new plugs and coil packs anyway, so I thought that was my problem. I just repalced the coil packs and plugs, (Bosch plugs and Bosch coils packs). I torqued everything to specs, and figured I was good. Started the car and the misfire is still there, cylinder #4. I checked the wires and connectors going into the coil pack, everything looks good. I looked at the old spark plugs and did not see anything out the ordinary or any fouling. At this point I am thinking perhaps a bad injector? My next step is going to swap out injectors with another cylinder and see if the misfire follows that injector. I have never done an injector but doesn't look that difficult, any advice before I do it? If the injector doesn't solve the problem I am not sure what the next step is.

Aquamania · #2 03-03-2016, 11:04 AM

Coil pack on number 4. Change it out. Also when was the last time you changed your plugs?

Aquamania · #3 03-03-2016, 11:05 AM

Oops see that you did that already. Follow the injector instincts.

lt2mc · #4 08-22-2016, 10:45 PM

I would like to hear what your solution was Mouncer. I just had my #3 coil fail on the way to work, swapped 1-with 3 and the problem followed. Replaced coil, all better

My first thought was injectors since I let the tank get below 1/4, so I will still do an injector clean (additive). This site is great!

bmrboi2 · #5 08-23-2016, 07:35 AM

I too Would love some insight. I have an engine miss that only seems to be prominent between 80-90mph. Its making me crazy. I don't have any vacuum leaks that I can tell. New Plugs, Coils, Vanos in/out. I am hoping its not an injector. I have never changed one and don't really want to learn how but I will if that's the issue. I have no codes/faults.