Very intermittent misfire/cam code issue - p0390/p0394

[jack28baker]

Really confusing issue I am having here. Any help is appreciated. After doing pac1234x springs, ops/cs, and new/upgraded timing components, my car has a odd and very intermittent issue where once every couple redlights/stops, it will misfire bad and it goes away right when i get back into rpms. 2 codes for my bank2 sensor 2 cam sensor (drivers side exhaust cam) and during the misfire events, it is usually cylinder 8 and sometimes 5. It will only misfire when coming to a stop, it will not start if i just sit at idle. I re timed entire engine today thinking it was a tooth off and am now a little clueless. Also replaced the cam sensor and that did nothing as well. Getting higher in rpms seems to get rid of the misfires instantly, say It is misfiring at 1k rpm, i will downshift and it will immediately stop. Some drives it will drive great, no issues at all. The drive after it might misfire at the first stop i get to. Everything I changed when doing the valve spring/opg job was all gaskets, opg/cs, pac1234x springs, boss 302 primary tensioners, secondary tensioners, phasers and cam filter, guides, primary/secondary chains, and went from amsoil 5w50 to mobil 1 5w30. I am having trouble thinking it is a mechanical issue due to how random and intermittent it occurs.

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[Timbuck]

Ok. There is a few things I’d look at. Due to its happening at low RPM it could be a stuck solenoid. This can occur if a bit of silicone or crap has got into it and it cannot return to it commanded position as it get back to idle. You could try and swap a solenoids around to see if the problem moves with theat exaust solenoid. Also can you do a data log and see what the cams are doing. It will give you a bass line to work from.
Also. Wires. The wires that go to the solenoids are fragile right where they bend over. Just make sure it all good there.

 

[Timbuck]

Oh. And also make sure it contacting properly as one of mine was bent slightly when I did my engine , and the centre pin wasn’t perfect 90deg

Edit. Video might help.

 

[jack28baker]

Ok. There is a few things I’d look at. Due to its happening at low RPM it could be a stuck solenoid. This can occur if a bit of silicone or crap has got into it and it cannot return to it commanded position as it get back to idle. You could try and swap a solenoids around to see if the problem moves with theat exaust solenoid. Also can you do a data log and see what the cams are doing. It will give you a bass line to work from.
Also. Wires. The wires that go to the solenoids are fragile right where they bend over. Just make sure it all good there.

I replaced both drivers side solenoids a few days ago hoping it would fix it, nothing changed pretty much. I will check the wiring though now.

 

[jack28baker]

*Update* did data-logs and the issue of course didn’t want to occur when i was logging, but looking at both exhaust cam positions, i can say that i can completely rule out timing being off. 30 minutes of driving and average exhaust timing was only .12 off bank 1 from 2.

 

[Timbuck]

Haha Murphy’s law. Never happens when you want it to.

Maybe playing with the wiring did something ??

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