1999 ME7 exhaust VVT CAM MAPPING

Post by **abscate** » 22 Apr 2022, 04:04

I’m convinced my exhaust VVT still isn’t set up right. I’m not getting any codes, but the engine doesn’t feel quite right, and I’m getting this behaviour on VVT. Mileage is down to 25 mpg highway, should be 27-29 mpg

: 609E82D7-1719-4FDB-AE24-81DF3CB8AF11.jpeg (1.1 MiB) Viewed 572 times

Basically, at idle 0 degree flank angle

Any throttle pressure, it jumps to 16 degrees and pegs there. If I lift, it stays at 16. If I lift and declutch, it falls back to 0 degrees. If I Rev while declutched , it jumps back to 16 degrees

I’ll map one of other ME7 exhaust VVT cars today.

Post by **abscate** » 22 Apr 2022, 07:06

Well my other ME7 car either has the same virus or it’s SOP

454cid · Post by **454cid** » 22 Apr 2022, 07:41

abscate wrote: ↑22 Apr 2022, 07:06 Well my other ME7 car either has the same virus or it’s SOP

If you look close, I think you'll see it's the inverse of the other car

Post by **abscate** » 22 Apr 2022, 07:44

It’s a RHD model

Post by **volvolugnut** » 22 Apr 2022, 09:40

This does not look like a useful valve timing adjustment. Why not just set for 16 degrees and not have adjustment? Can you record under load and actual acceleration?
volvolugnut

Post by **abscate** » 22 Apr 2022, 09:53

Both of those traces are during short town drives. With the M56 you can see where I shift as the valve timing drops to idle. The AWD doesn’t have that as the engine never drops to idle , of course,

Post by **volvolugnut** » 22 Apr 2022, 10:49

Maybe this is correct. Valve timing 0 degrees at idle for good idle and 16 degrees above idle for good flow. Still, I would expect to see more variation with RPM.
volvolugnut

Post by **Chuck W** » 25 Apr 2022, 06:51

Did you happen to grab the RPM and load plots for those segments as well?

I need to get back to messing with the exVVT on the wife's car. We've got one of VAST's PWM VVT control bins on the M4.4 ECU controlling the '02 turbo motor we have in there.

Aaron's original map for the VVT looked similar to how that stock plot looked, but boy was the car NOT happy with that.

The M4.4 set-up has no way to determine what the cam angle is, so it's hard to say what we're getting, but advancing the exhaust cam under load/cruise did not do nice things for drivability. Really weird.

Post by **abscate** » 25 Apr 2022, 17:30

I can take those plots with my shiny new Autel scanner.

Post by **FireFox31** » 25 Apr 2022, 21:44

Can VIDA get these plots, including VVT with RPM and load? I think mine is messed up too and would love to see the real data.

Or just clean my exhaust VVT solenoid and see if it all gets better.