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Thanks all for the quick response ...

I have replaced an E38 ECM and need to clear the P0315 crank position sensor learn error.

I had used the old CKP version of this.

Unfortunately none of the DVT functionality is currently...

It's running in stock MAF mode with stock narrowband O2s.

I added 12 degrees of advance in the 1280/0.28 area and a proportionally smaller amount going out in the base idle spark table and this along with a 60% increase over stock in cranking idle air seems...

I added quite a bit more idle air (+50%). Most cases now result in partial stall that takes two oscillations to recover stable idle. There must be some other underlying issue.

I will try +20%...

Thanks for the response ...

The issue seems to be temp independent. I'll try more idle air and see if this helps.

I've got a new engine idle problem (E38 ECM) I need some help with. This engine is running well. It starts and idles perfectly. It comes to a clutch-in stop from street speeds and drops to idle...

Thanks for the further info,

I increased idle air 6% and increased the 0.20 cylinder air timing in a few of the lower rpm cells to match the 40 degree advance in the cells above. These both seemed...

Swingtan,

The hot start stability is much improved. I'm guessing this is mostly due to the increase in hot cranking idle air.

There is still a little hot start idle oscillation but that seems...

Thanks, I'll give this a try and let you know the result.

Thanks for taking a look guys.

Here's the tune. I've also attached a cold start log and an image of the cold start from OL to just past CL so you can see that the oscillation doesn't occur there....

I have a cam'ed C6Z that has some transient idle instability immediately after a hot start. Cold starts don't have this idle oscillation.

The ECM has not been AutoVE'ed as yet - I'm waiting...

Yes

Problem resolved ...

I noticed the machine I was using didn't have the latest 7.5 update installed. Once installed, the CASE gave me a 'no brake pedal error'. With the brake pedal, CASE set the...

I just installed a cam in a C6 Z06 Corvette and soon after a P0315 DTC appeared. I believe this indicates that a crank position sensor relearn needs to be done.

The Scan Tool documentation on...

Lambda = AFR/AFR Stoich so AFR=AFR Stoich*Lambda
EQ=AFR Stoich/AFR so AFR=AFR Stoich/EQ

The SAE spec is in error. Somewhere it must say that EQ=1/Lambda. EQ is proportional to fuel so it doesn't...

Actually, Lambda is proportional to AFR. EQ is inversely proportional to AFR.

Lambda is the ratio of AFR/AFR Stoich - EQ is 1/Lambda. Lambda > 1 is lean; EQ > 1 is rich.

Having EQ reported as...

After loading a BB Log (created prior to the beta of 8.1.2) with 7.5.5 (Build 83) Scan on XP, I export a few of the PIDs as CSV. All works correctly.

The problem is that after the export, the...

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.

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...

Version 8.1.2 correctly lists the units of EQ_RAT as EQR.

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...

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.

No one has commented yet on my issue with the PE values being output by the EQ_RAT PID.

This is supposed to report the commanded EQ Ratio but its PE values don't seem to make sense. Has anyone...

Yes, this resolved the issue. Thanks.

I created the log with BB logging so I didn't realize that there was a logging limit or that it inhibited display of frames in prerecorded logs.