Engine troubleshooting tools: OBDII, ISTA, INPA?

[filtercoffee]

I'm trying to pinpoint the cause of a minor annoyance I have with my Z4M.
At high load (near WOT) between 3-4k RPM, I can feel and hear a minor oscillation in power. It almost feels like the the throttle valve is slightly modulating twice a second, or the vanos advance is modulating, or it could be fuel trim or ignition timing or wonky MAF readings. Your guess is as good as mine. To throw another variable into it, the car is running epic's race tune.

To narrow this down I want to log as much data as possible to see what's happening. I have a bluetooth obdii reader with Torque Pro but it doesn't have all the PIDs. For example there's no vanos information as far as I can tell.

What tools do you use to diagnose tricky problems? Anyone have a PID list I can input into the obdii reader app? I haven't tried ISTA/INPA yet but I have K+DCAN cable, is it worth it?

[rjahl]

Originally Posted by filtercoffee

I'm trying to pinpoint the cause of a minor annoyance I have with my Z4M.
At high load (near WOT) between 3-4k RPM, I can feel and hear a minor oscillation in power. It almost feels like the the throttle valve is slightly modulating twice a second, or the vanos advance is modulating, or it could be fuel trim or ignition timing or wonky MAF readings. Your guess is as good as mine. To throw another variable into it, the car is running epic's race tune.

To narrow this down I want to log as much data as possible to see what's happening. I have a bluetooth obdii reader with Torque Pro but it doesn't have all the PIDs. For example there's no vanos information as far as I can tell.

What tools do you use to diagnose tricky problems? Anyone have a PID list I can input into the obdii reader app? I haven't tried ISTA/INPA yet but I have K+DCAN cable, is it worth it?

Can't beat TestO for logging, Maybe Bimmergeaks tool can manage this platform but I'm not sure.

No off the shelve ODB reader is going to work for you.

[3002 tii]

Assuming you already tried pulling codes with a generic reader?

I use INPA, really simple to use. ISTA-D is good but haven’t played around with it enough. But for diagnostics I don’t think one has either been able to pull any codes that a normal handheld couldn’t. They were more useful for certain reset type procedures. Carly used to be good before they switched to subscription pricing.

[filtercoffee]

yes, no engine codes.
I really want to log vanos values.

[3002 tii]

Originally Posted by filtercoffee

yes, no engine codes.
I really want to log vanos values.

But you might still have shadow codes which would not show up with a generic code reader. Regardless you should get INPA at very least since it's basically free (just PITA to install). A decent cable is $30 and it'll pay for itself after one use. Re vanos, I don't recall it being an option with INPA. With ISTA I know you can definitely bleed/test but not sure how you'd do the logging. Sorry not the answer you were looking for...