VVT Intake angle oscillation / issues
 

I've always had stumbling issues at low speeds and just always lived with it. I was logging through ecutek to look at knock testing a new gas station (76 vs Valero) and saw that at idle my VVT angle was oscillating (It shouldn't) and it also didn't follow the exhaust angle very closely like it should. VVT is enabled as you can see in the pictures below. Also a datazap log of just cruising down the highway

https://datazap.me/u/s0007/win10-val...-43-44&solo=19

I'm wondering if anyone has suggestions or seen this before. I have an edelbrock SC with Delicious tune. Don't think its a tune issue but could be my solenoid or cam sensor. Couple questions for the community

1. How do I tell which intake solenoid is oscillating? seems like ECU doesn't really distinguish this
2. Shouldn't the VVT intake be very close the the VVT exhaust angle? in my logs above there's huge offsets between the two (10-30 degrees)
3. I know there's a solenoid problem with many revisions in those parts has anyone seen this type of problem corrected with new revisions?

vvt intake should follow vvt intake target angle, as the vvt exhaust would follow the respective target, they aren t the same

anyway is a common problem, see if it correct after a full gas pull, usually if it correct itself and start to rest at 0 instead of oscillating, it s a mechanical problem in the vvt intake #1 gear and needs replacing to correct it

vvt intake should follow vvt intake target angle, as the vvt exhaust would follow the respective target, they aren t the same

anyway is a common problem, see if it correct after a full gas pull, usually if it correct itself and start to rest at 0 instead of oscillating, it s a mechanical problem in the vvt intake #1 gear and needs replacing to correct it

1. I've never been able to figure out how to log the individual servo channels with tactrix. I'm still bummed about that. I do monitor at a much lower sample rate with obdlink.

2. No

3. There is no problem with your vvt. The part you're sweating is a couple degrees of oscillation at a nine-second period while idling.

I realize now that intake and exhaust is going to be very different depending on the tune and the maximum torque targets in the base maps at different RPMs. Also found a YouTube video of how they teach cam timing tuning on an 86!

Primarily was looking at the oscillations and thought that it could be indicative that its not following the commands targets as well as it should in the map at other RPM points as well. Obviously its not a big enough difference to throw a CEL. Ill probably swap the exhaust and intake OCVs on both sides and see which side has the oscillation follow the OCV and go from there.

https://youtu.be/G7NB4HXC_Fg