Maddening misfire issue between 3200 and 4200 RPM

[honeybadger]

This is the only thing with the word "relearn" in it:

Huh - could've sworn it was there. Might be only available through the dealer or tuners. Either way, I doubt that is your problem. Do a live monitoring session of injector voltages

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[shanewendel]

Huh - could've sworn it was there. Might be only available through the dealer or tuners. Either way, I doubt that is your problem. Do a live monitoring session of injector voltages

Thanks, I will do so on a drive tomorrow. However, there don't seem to be PIDs for individual injector voltages, only faults and an aggregate monitor.

I did notice a weird vacuum sucking sound when feathering the throttle lightly and a clink when giving it just a bit more. I'm assuming that's the throttle body opening/closing, but the sucking sound seems like it's coming from the lower part of the engine. Need to get someone to tap the throttle for me so I can listen from the engine bay. I have no idea if either of these are normal

 

[Tank]

Did you check the link I posted?

EVAP and EGR valves are listed as possible causes. You’re reporting vacuum noises...

 

[shanewendel]

Did you check the link I posted?

EVAP and EGR valves are listed as possible causes. You’re reporting vacuum noises...

Yes I did. If you have a diagram showing exactly where those are, I can check them. Parts diagrams don't show where they are on the car.

 

[Tank]

Yes I did. If you have a diagram showing exactly where those are, I can check them. Parts diagrams don't show where they are on the car.

I linked the HD Pinpoint test to the link I posted above. It should give you some idea where to look. Tests lead to test that lead to other tests. It can be quite a rabbit hole. Let me know if there's anything else you might want looked up.

I will also try to find the EVAP and EGR valves as requested. If found, I'll let you know here.

 

[shanewendel]

I linked the HD Pinpoint test to the link I posted above.

I will also try to find the EVAP and EGR valves as requested. If found, I'll let you know

Is all of that from the service manual? Maybe I should just get the 2 day license.

Thank you so much by the way, I appreciate it.

 

[FLATPLANE]

Possible PCM Issue, No Mods to the engine? Any work to the car done recently?

 

[Tank]

Is all of that from the service manual? Maybe I should just get the 2 day license.

Thank you so much by the way, I appreciate it.

You're welcome. Thanks for saying..

Yes, those pages were from the Helm Manual. There are a couple of Service Manual products out there with their pros and cons. I'm not too familiar with the Motorcraft subscription services but would think a limited subscription would get you what you need. (I did a two day subscription for Toyota and downloaded a ton of information I knew I would want - worked great for me.) I looked into automatic downloaders and the such but it wasn't anything I could figure out.

I did look for any sort of diagram for the 5.2 but couldn't find anything that would have clearly shown where things were. My offer still stands if you want me to dig a bit deeper into anything.

Good luck , I'm sure you'll get this worked out soon.

 

[shanewendel]

Possible PCM Issue, No Mods to the engine? Any work to the car done recently?

None that I know of. Car was traded into an Audi dealer with 7200 miles, about 4 months ago, I bought it about a month ago and daily'd it (mostly highway commute) for a few weeks, got the CEL on my first backroad drive.

Car was reflashed today with the latest calibration under the exhaust flap TSB. I was hoping that it had been poorly tuned or something and that would be the magic bullet, but no dice.

I didn't tell the dealer that flashed it about the CEL because I'd want a different dealer to do any mechanical work, they have an SVT certified tech, but also a long line of cars waiting for him.

Still hoping it's something silly I can find and resolve.

 

[11GT50]

You have a bit different circumstance than I do but are you able to log fuel pressure by chance? I have a P0300 as well but it came with a P0192 and no other misfire code. I get intermittent loss of fuel pressure - down to 0 then returns to normal - under load. I don't think our issues are related but I'm still curious.

 

[Tank]

None that I know of. Car was traded into an Audi dealer with 7200 miles, about 4 months ago, I bought it about a month ago and daily'd it (mostly highway commute) for a few weeks, got the CEL on my first backroad drive.

Huh, wonder if that was related to the misfire???

 

[shanewendel]

Huh, wonder if that was related to the misfire???

It's certainly possible, although I don't see how it wouldn't have popped up on my test drive. Only warranty work on the Oasis report was the previous engine replacement.

 

[shanewendel]

If I swap an injector around or even replace (looks like they're only $20), would it require re-coding?

I'm not getting any injector faults, but that seems like the most likely culprit.

 

[honeybadger]

If I swap an injector around or even replace (looks like they're only $20), would it require re-coding?

I'm not getting any injector faults, but that seems like the most likely culprit.

Nope. I did the same when I was hunting down a similar problem (although mine was on idle)

 

[shanewendel]

What's this little primer bulb thing?

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