E38 LS7 EQ_RAT and EOILTS Issues

[hapnermw]

I may be wrong, but it seems to me that EQ_RAT is behaving like Lambda instead of EQ.

Sanity check: have you set your fueling units to AFR or EQ and not Lambda...?

The E38 calibration is the latest stock calibration for my VIN from TIS so whatever EQ_RAT is reading is whatever GM has set it to.

[joecar]

In the scantool, on the PIDs tab, it shows the units of EQ_RAT being Lambda.

[hapnermw]

In the scantool, on the PIDs tab, it shows the units of EQ_RAT being Lambda.

The 'lambda' units just mean that the range of EQ is the same as the range of lambda which it is. Clearly EQ is the inverse of lambda.

The .829 PE reading I'm getting doesn't make sense for either EQ or lambda. If it were lambda it would be 12.1 AFR. I know for a fact that the stock commanded PE EQ is in the low 11s. Readings on my scan vary but one .829 reading corresponds to LC1 Bank 1 11.11 Bank 2 10.96.

As soon as my beta BB Logging starts working again I'll scan both commanded EQ and AFR and report back the results.

The reason I was scanning commanded EQ instead of AFR was I thought it might be more accurate since California gas is 91 Octane and Stoich differs from the 14.68 the ECM assumes. I'm assuming commanded AFR should be exactly 14.68/EQ_RAT.

[joecar]

EQ_RAT is in Lambda, so commanded AFR should be 14.68 * EQ_RAT, assuming your stoich AFR is 14.68.

Edit: I meant to say 14.68.

[hapnermw]

EQ_RAT is in Lambda, so commanded AFR should be 14.68 * EQ_RAT, assuming your stoich AFR is 14.63.

Version 8.1.2 correctly lists the units of EQ_RAT as EQR.

[swingtan]

Here's a log I just did comparing the the following...

AFRATIO_DMA
EQ_RAT
WB_AFR




As you can see, EQ_RAT tacks AFRATIO_DMA and it does it precisely. I have bumped the scale for EQ_RAT as if I set it directly match AFRATIO_DMA, the 2 lines lie directly over the top of each other. Also note that the default units for EQ_RAT is "lambda".

So going back to post #9 as well as post #14....

EQ_RAT=Commanded AFR / Stoich AFR

[hapnermw]

Thanks swingtan,

Now that 8.1.2 logging is working for me and it has changed EQ_RAT units to EQR, possibly it will correctly show commanded EQ as the inverse of commanded AFR.

I'll check this out.

[hapnermw]

With an 8.1.2 BB log of commanded AFR and EQ displayed with Scan 7.5, the EQ_RAT PID is still displaying Lambda instead of EQ. Perhaps Scan 8.1.2 will fix this.

[joecar]

I notified Paul.

[Blacky]

Apart from the EQ_Ratio units showing up as lambda, I can't see any other problems.

EQ Ratio is directly proportional to AFR, so EQ Ratio should track AFR.
Lamba is inversely proportional to AFR, so Lambda should inversely track AFR.

Or am I missing something? (It happens, often :( )

Regards
Paul