jackg0037
New Member
- Thread starter
- #1
Hey everyone im new to this group but have read many forums in here and sorry for this long post but I could use a hand I’m honestly stumped.
I have a 15 gt pp1 mt82 just hit 80k miles. It will misfire/skip/pop at idle or with light throttle just in neutral with no load. No codes and It’s intermittent and will idle normal other times videos are just cut down so they’re not long lol. Has a boss 302 manifold with a factory intake, catless long tube headers, h pipe and magnaflow mufflers along with a Lund tune for the manifold and was only replaced because imrc’s took a dump.
This pop is more noticeable out of the passenger tail pipe
I have replaced
-4 vct solenoids
-maf sensor
-coils and plugs
-crank position sensor
-both intake and exhaust cam sensors
-driver and passenger upstream o2’s
All have been oem ford
Supposedly throttle body and injectors were all brand new 5k miles ago but dealership also said that about the manifold…
Afr at idle bounces between 13.6-14.2 on dash
Intake cam ounces between 29.7 and 30.2 and is being commanded to sit at 30
Exhaust cam bounces between -0.12 and 0.06
Short term fuel trims bounce between .98 and 1.01 for both banks
At idle Long term fuel trim on bank 1 sits around 0.98 and 1.01 but bank 2 will sit around 1.15 which I know isn’t normal but I don’t see the short terms trying to make up for it. And while driving they both go back to normal percentages and both banks sit around .99-1.02
Fuel pump duty cycle is 29% at idle
Battery voltage is good from what I can tell reads 14.2v on the dash
Vacuum gauge reads around 18 and doesn’t fluctuate
Don’t see or feel any noticeable exhaust leaks anywhere
Checked for vacuum leaks by spraying starting fluid on all possible spots but didn’t notice any change in rpm
Disconnected both catch cans to see if one was letting in air but that didn’t change it
Have done a few kam resets and multiple crank relearns with nothing changing.
Purge valve tests okay and have even tried running it without it connected to the intake and plugged the port.
Will sometimes pop when downshifting, not just burble but like one single pop
I haven’t been able to check the misfire counts in forscan but can try to soon and see if that gives me any more info.
And I thought maybe it was a phaser taking a dump but my sct not seeing it so I checked the logs and they’re pretty steady for both intake cams and both exhaust cams.
Other thought was maybe a tune issue but was told everything’s normal and tan it with the factory tune and idle the same just threw a code for imrc’s
Correct me if I’m wrong but I honestly don’t think it would be low compression since it’s so intermittent and only at idle car has plenty of power when driving. But I have not tested it
If anyone has any input I’d greatly appreciate it and if there’s any info I may be missing that could help I’d be happy to look into it.
I have a 15 gt pp1 mt82 just hit 80k miles. It will misfire/skip/pop at idle or with light throttle just in neutral with no load. No codes and It’s intermittent and will idle normal other times videos are just cut down so they’re not long lol. Has a boss 302 manifold with a factory intake, catless long tube headers, h pipe and magnaflow mufflers along with a Lund tune for the manifold and was only replaced because imrc’s took a dump.
This pop is more noticeable out of the passenger tail pipe
I have replaced
-4 vct solenoids
-maf sensor
-coils and plugs
-crank position sensor
-both intake and exhaust cam sensors
-driver and passenger upstream o2’s
All have been oem ford
Supposedly throttle body and injectors were all brand new 5k miles ago but dealership also said that about the manifold…
Afr at idle bounces between 13.6-14.2 on dash
Intake cam ounces between 29.7 and 30.2 and is being commanded to sit at 30
Exhaust cam bounces between -0.12 and 0.06
Short term fuel trims bounce between .98 and 1.01 for both banks
At idle Long term fuel trim on bank 1 sits around 0.98 and 1.01 but bank 2 will sit around 1.15 which I know isn’t normal but I don’t see the short terms trying to make up for it. And while driving they both go back to normal percentages and both banks sit around .99-1.02
Fuel pump duty cycle is 29% at idle
Battery voltage is good from what I can tell reads 14.2v on the dash
Vacuum gauge reads around 18 and doesn’t fluctuate
Don’t see or feel any noticeable exhaust leaks anywhere
Checked for vacuum leaks by spraying starting fluid on all possible spots but didn’t notice any change in rpm
Disconnected both catch cans to see if one was letting in air but that didn’t change it
Have done a few kam resets and multiple crank relearns with nothing changing.
Purge valve tests okay and have even tried running it without it connected to the intake and plugged the port.
Will sometimes pop when downshifting, not just burble but like one single pop
I haven’t been able to check the misfire counts in forscan but can try to soon and see if that gives me any more info.
And I thought maybe it was a phaser taking a dump but my sct not seeing it so I checked the logs and they’re pretty steady for both intake cams and both exhaust cams.
Other thought was maybe a tune issue but was told everything’s normal and tan it with the factory tune and idle the same just threw a code for imrc’s
Correct me if I’m wrong but I honestly don’t think it would be low compression since it’s so intermittent and only at idle car has plenty of power when driving. But I have not tested it
If anyone has any input I’d greatly appreciate it and if there’s any info I may be missing that could help I’d be happy to look into it.
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