MembersPage/JimW (2005-07-12 23:43:42)

Switching to Genboard on my Golf racer, because K-Jet isn't cutting it. Later on I will be doing forced induction, so I need room for change.

Pictures and some info:

http://proton.shadowflux.com/vwracing/

email james at shadowflux dot com


WBO2 question:

All wiring is correct, I have double checked. wbo2_pump_pw (0x63) is calibrated correctly, voltage is -0.03V. Measured Rcal at 127 ohms, so wbo2_calibration is set to 0xB0. Attached sensor to do free air calibration, command mde02, sensor heat comes up to maximum (0xE4) and O2% appears on LCD mlp07. As soon as heat is maxed, drops to 0x00, pauses then comes up to a reasonable level gradually. As soon as O2% appears on screen, value changes VERY rapidly from 20.9x% to 11.xx% to 17.xx% to 19.xx%, in no particular order. Ri stays between 0x90 and 0xAD. Any ideas what is going on here? All of this is without engine running.

More info:

Did some testing last night with 100ohm resistor method. Nernst was at 3.96V at first (nernst_dc_target=8D), raised it gradually to 0xBD to get to 4.47V. (I suspect that integral was too low, not enough to push PID error down to zero)

Intermediate nernst_dc_target values resulted in wavering (by about 0.2V, instead of the max 0.1V allowed maximum) Nernst voltage. When nernst_dc_target was raised to 0xBD, Nernst voltage was dead steady at 4.47v (maybe pump was railed at max FF?).

WBO2 testing page says I need 3.96V+0.45V=4.41V sortof steady, so lowered nernst_dc_target to 0xB7, but voltage started to waver again. With values where Nernst voltage wavers, pump value (on mlp07 of LCD) is a value such as 0xC3, jumps to FF briefly, then back down to 0xC3 (0xC3 is just an arbitrary number. actual value is above 0xC0, but I don't remember what it was).

When measuring nernst and pump-, I have varying values. I think the values i measured were bouncing between 120mv and 150mv. They are written down at home, I will post later.

I changed wbo2_pump_pidki from 0x40 to 0x20, but didn't see a difference in voltage values. Should this affect the bouncing of voltage up and down when measuring nernst (to ground) voltage and nernst to pump- voltage?

yes, it sounds like a WBO2 PID configuration issue (oscillation), because your WBO2 pump (HW) seems to react. Play with the values, especially pump_pid....

eg. try this:

Wow Marcel, those settings were VERY close to dead on. Only had to adjust the wbo2_calibration and bring nernst_dc_target back down to reasonable values. Got the WBO2 working tonight before I loaded it onto the trailer. Thanks! I will post updated config after I get back.0


RPM reading issue

Ignition is controlled by ... (GenBoard ?)

Injection is contolled by ... (GenBoard ?)

Made a log of rpm, it reads 3000-4000 rpm at idle, which is really 900-1000 rpm. RPM drops to ~600 for two to three samples, then back up to 3-4k.

If the VR is shared with another ECM, we need to examine the situation further (maybe a 10uF 1210 size series cap needed).


Config

Latest/revised comments config: MembersPage/JimW/Config

Notes about subsystems (to verify/justify config variables) on pages below


My Genboard and LCD display:

genboard_32_1.jpg lcd_box_1.jpg lcd_box_2.jpg