View Single Post
Old 07-28-2020, 07:48 AM   #3 (permalink)
INFmstrTech
Base Member
 
INFmstrTech's Avatar
 
Join Date: Nov 2018
Location: Near Frisco, TX
Posts: 42
Drives: 08coupe, 07sedan
Rep Power: 6742
INFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond reputeINFmstrTech has a reputation beyond repute
Default

I think your overthinking it. You don’t have to have the same voltage reading for the VVEL to properly work. Spec is 500mV +- 48mV. The only thing that you’re actually doing is setting the position sensor at a certain voltage so the control module knows where the shaft is at, from there it will take actual values and adjust accordingly. Out of the 100 or so VVEL engines I’ve rebuilt doing the VVEL Position adjustment can yelps weird results. IE: the position sensor never has an in spec reading no matter what way you turn it...but most of the time the position sensors will read slightly different. long story short is that you successfully adjusted them so don’t sweat the voltage difference...check out the attachment and look at the sensor learn values. They differ but are in spec. The other values don’t match but the car operates perfect!

Quote:
Originally Posted by sirnixalot View Post
I have tried everything I can think of which I will outline below. I'm about to start researching how to keep AC and do HR heads or something.

Background info
Built bottom end, refreshed heads, JWT exhaust cams and springs

Issue 1
I CANNOT for the life of me get the VVEL position sensor voltages to match. Bank 1 is constant and no issue, Bank 2 reads 0.1v less. If i sync the voltages as per FSM with the car off the "VVEL angle" on bank 2 is off a few degrees. Start the car up and it will match the angles but the position voltage will be 0.1v less on bank 2


Issue 2
Dependent on the gear, it appears to be a load related issue to me, the car will lose power and air flow will drop on Bank 2's MAF. This only happens during WOT and will not happen under part throttle. 2nd gear it happens at around 7000rpm, 3rd gear around 6500rpm and 4th gear at 5500rpm.

Also of note, Bank 2's MAF will read between 0.3 to 0.6 volts higher until it falls off drastically.

Thing's I have done so far.

Toned out the wiring between both position sensors and the VVEL ECU (all good 0 ohm readings)
Replaced both VVEL ladders
Replaced both VVEL motors
Replaced both VVEL position sensors
Replaced the VVEL ECU

When replacing the VVEL ladders, I left the valve covers off, manually adjusted the VVEL control shaft to minimum position and set the position sensors to read 0.5V. This still resulted in Bank 2's actual angle being lower than Bank 1.

I don't want to keep throwing parts/money at it. Maybe this motor is just cursed? Anyone been through this before?
Attached Images
File Type: jpg 207CE28B-4A14-4C54-8504-9BB93195E59F.jpg (284.8 KB, 34 views)
__________________
‘08 coupe w/Stillen SC, Custom A2A, SD, ID1050x, e85, eagle rods, high temp coated pistons, P&P heads, JWT C2, manual swap, stage 2 clutch. EcuTek(Eugene)
INFmstrTech is offline   Reply With Quote