Cyl 4 misfire

[Mxer0022]

Alright all you ecoboost geniuses. Got a cyl 4 misfire on a trip. Stopped at an auto zone and bought a coil pack and new plugs. Only replaced the coil pack and it seemed to take care of the issue. Got home and went on another short trip before I had a chance to replace the plugs and noticed a small miss climbing a steep grade but never threw a code or went into limp mode. Always seemed to happen while under a load. Just finished replacing the plugs and I didnt even make it out of the valley we live in under a very light load it through a cyl 4 misfire code and went into limp mode. Any clue as to where to look next? Should I replace all the other coil packs? Can another cylinder be misfiring and the computer is reading cyl 4? Cyl 4 is front driver side hole right?

 

[BMW2FORD]

Next step would be to remove the intake a swap both injectors (gen 2's have a direct and port fuel injector) to other cylinders and see if it travels but before you do that, was the boot replace also between the coil and spark plug? I never trust aftermarket parts so maybe just pull that replaced coil and boot from #4 and swap it to cylinder #5 just to be sure before going towards the injectors. You might see it come and go like this since the injection on these switches from port to direct depending on load and drive cycles so that might be why it was gone for a while but back. Cylinder #4 is on the front drivers side. With only one misfire, I don't think its another on the opposite side of the firing order. Older cars with V8's, 10's and 12's could have a companion cylinder in the firing order misfire and trip multiple misfire codes sometimes but rare on a 6 cylinder especially with the accuracy of today's misfire detection.

 

[uaee]

Cylinder 4 is first one in driver side
There are several things could cose misfire like spark plugs, coils (not likely to go bad)
Bad injector also vacuum leak you need to check those first if all are good then do a leak down test

 

[NukeLife]

Are you using OEM parts?
I had the exact same cylinder misfire (4), intermittent, and only when under load. Felt the most, when gradual acceleration on an incline, or when pulling a load.

replaced all six plugs with OEM plugs (use the dielectric grease) and the problem went away.

As others have suggested, I would swap the coil and and plug to another cylinder and see if the problem moves with it.
Also, did you check the gap on your plugs before you installed them?

 

[DWs-TTEB]

so stock plug gaps are .031 but I’ve read folks with tunes are running NGKs at .028. I’m tuned with 5Star & planning on doing new plugs and boots soon. I’m at 47K OD. Thoughts from the community on this?

 

[DWs-TTEB]

Set of 6 NGK LTR7BHX (95605) Spark Plug | ZFG RACING LLC

NGK Ruthenium HX is designed for newer engines which demand high ignitability. Projected Square Platinum Electrode (PSPE) design promotes spark energy concentration and ignites a wider range of air-fuel ratios, offering improved performance in rich or lean engine conditions. 0.4mm Ruthenium...

www.tunedbyzfgracing.com

Are these NGKs gapable? Thinking of buying the .031 to save $20 & gap them myself to .028

 

[DWs-TTEB]

ZFG there wants $15 for shipping 6 plugs. So getting 6 gapped at .028 + shipping = $100! Looking else where

 

[Mxer0022]

So I tried swapping the cyl 4 pack with cyl 5 and nothing changed. Just spent $600 on oem replacements on all 6 cylinders and nothing.

I dont have the time to continue swapping parts out to find out it didn't work so I've gotta take it to the dealership. I've gotta leave on a work trip for possibly a couple weeks next week and the wife needs her car to haul 3 boys around to baseball practices and to and from school so it's gotta get done asap.

I'll update when I find out what the problem is.

 

[DWs-TTEB]

Set of 6 NGK LTR7BHX (95605) Spark Plug | ZFG RACING LLC

NGK Ruthenium HX is designed for newer engines which demand high ignitability. Projected Square Platinum Electrode (PSPE) design promotes spark energy concentration and ignites a wider range of air-fuel ratios, offering improved performance in rich or lean engine conditions. 0.4mm Ruthenium...

www.tunedbyzfgracing.com

Are these NGKs gapable? Thinking of buying the .031 to save $20 & gap them myself to .028

Found my own answer. Yes they are (re-gapable). Thanks YouTube/Google-Magic!!!

 

[Mxer0022]

So the preliminary diagnosis is a leaking #4 injector. Can a leaky injector cause it to miss as bad as it was?