Engine misfiring

[Grandstaff]

I got my car tuned for my dod delete a few weeks ago, and on the way home after turning a right thr car started driving funny and misfiring, I figured it was an issue with the tune, because there were no codes. Anyway I had to fix a couple things unrelated to the engine and bring the car back to finalize the tune so I just took it today to get told by the tuner that the issue is not with the tune and likely with the spark plug wires or cylinder 7 coil pack, well I quickly went to oreillys grabbed some new wires and a coil pack in hopes that it would work, but to no avail. I'm just stumped as to what it could be, the car just has not much power when driving. Any ideas would be greatly appreciated

[Sanford]

If you have cylinder misfiring, you should be getting a CEL. I believe misfire detection can be turned off with HP Tuners, but I may be wrong. Get a noid light and see if you are getting a signal to #7 injector. Might want to run a normal compression test and also a running compression test on #7 along with a couple others for comparison. Could also have a plugged injector.

[GammaFlat]

I have a 13 with 65K miles. I had a miss that would eventually turn into a CEL. It didn't miss when cold. It seemed to start missing after 10 minutes of running. And it usually got worse over time as if it might have been missing on multiple cylinders. I changed the plugs and wires which made it run well. That was a couple months ago and although I haven't put many miles on it, I've not had one hiccup.

[Grandstaff]

If you have cylinder misfiring, you should be getting a CEL. I believe misfire detection can be turned off with HP Tuners, but I may be wrong. Get a noid light and see if you are getting a signal to #7 injector. Might want to run a normal compression test and also a running compression test on #7 along with a couple others for comparison. Could also have a plugged injector.

I measured all the injector connectors with my fluke and they were all reading 12.5 ohms so I don't think it's an injector electrical issue. I found out with my blue tooth obd2 scanner I can read misfires per cylinder so I can narrow it down from there, and use my inline spark tester to check coil packs, and if that's not the issue I'll get a injector tester/cleaning kit. And then I'll go from there.

[Grandstaff]

If you have cylinder misfiring, you should be getting a CEL. I believe misfire detection can be turned off with HP Tuners, but I may be wrong. Get a noid light and see if you are getting a signal to #7 injector. Might want to run a normal compression test and also a running compression test on #7 along with a couple others for comparison. Could also have a plugged injector.

I measured all the injector connectors with my fluke and they were all reading 12.5 ohms so I don't think it's an injector electrical issue. I found out with my blue tooth obd2 scanner I can read misfires per cylinder so I can narrow it down from there, and use my inline spark tester to check coil packs, and if that's not the issue I'll get a injector tester/cleaning kit. And then I'll go from there.

So far I am still completely stumped, I have used a noid light tester with no problems, I did a leak down test which passed with flying colours, I have swapped injectors and the issue did not follow, I took out the spark plugs and left them attached to the spark plug wire to see if they were fouled, which they weren't. I have cleaned my maf sensor, pcm plugs, and every plug there is. I just can't for the life of me figure out what this issue is.

[s/c'd cav]

did you do a compression test ? have you inspected the valve springs ? check the valve movent on that cylinder comapred to the others ?

[Sanford]

As mentioned, might be time to pull a valve cover, inspect the valve train components and see what the valves are doing at idle.