Bad MAF calibration post Head/Cam swap - help?

[bimbleuk]

Hi,

Quick spec.
LS1
LS6 plenum
Edelbrock 80mm TB
LS2 MAF
Custom SS exhaust front to back.

I've been using CALC.VET fine for several months to get my LS1 well tuned. MAF and VE were consistent and trims were 0 - 2% at worst.

So with some confidence in my ability to tune the car I decided it was time to install a set of 243 heads and a Comp Cam 222/224 566/568. I had no issues with the swap and the car is driveable as it is plus the idle is pretty good already after an RAFIG and timing tweaks.

So I tried to do a CAL.VET with trims disabled to use the WB correction only. I did an initial run and when I looked at the MAF corrections it was averaging x1.7 - 1.9 across the range. So I thought that can't be right and enabled the trims again and did a CALC.VET using SELBEN for the MAF

The problem seems to be that around mid-range on the MAF scale the corrections just go up rapidly and the MAF appears to quickly max out? Is that possible? Any suggestions as everything appears just as before bar the heads & cam.

Example corrected MAF below and the calculated VE. Lower VE looks good until the MAF shoots up

15564 15565 15568

Here's the MAF prior to the head and cam swap.

15566

CALC.VET tune file I was using.

15567

[bimbleuk]

Here's a couple of logs

First log of CALC.VET no trims
15576

Last log with trims enabled
15577

[joecar]

I'm still looking thru your files...

[bimbleuk]

Thanks

I was miffed at not being able to get the calibration down as the head swap had gone so well. I have very little time early in the mornings to get any space for decent log runs. The correction in the logs jumps part throttle when plotted so I'm now thinking I've got a bad config somewhere.


Here's the calc_pis.txt file I was using. I edited it depending on if the trims were being used or not.
15579

[joecar]

Sorry, I got severely delayed yesterday, I'm still looking thru your logs.

[joecar]

...


Here's the calc_pis.txt file I was using. I edited it depending on if the trims were being used or not.
15579CLC-00-305 looks correct (using SELBEN).

Note that you must have at least 2 blank lines at the end of the calc_pids.txt file.

[bimbleuk]

CLC-00-305 looks correct (using SELBEN).

Note that you must have at least 2 blank lines at the end of the calc_pids.txt file.

Good to know and I deleted them just before uploading the file so that wouldn't have been a problem when mapping. Bad habit from editing Powershell scripts during the day!

The car is stored away from my home so I get the odd chance to access it. I looked all over the top end today for anything I messed up during the swap. Unplugged wires, pinched hoses, manifold sat down, headers flat against the head etc.

Next chance will be the weekend to plug the Flashscan back in for diags. I work most Saturdays too just to add to the frustration!

I appreciate any suggestions.

[bimbleuk]

I've been checking my tune files and changed B3605 to match the AutoVE values. Not sure how relevant that is but I must missed that table when I changed back from a custom OS.

[joecar]

Post pics of your B3605 and B3618 if theyve changed since CAL_VET.tun (http://forum.efilive.com/attachment.php?attachmentid=15567&d=1374406013) in post #1 above.

I'm still multitasking, I have your files open on one of my PC's, I'm sorry I'm so slow.

[bimbleuk]

I've just finished a work project for this week early so had time to look at the logs a bit more and I may have missed an obvious error. The WBO2Lam1 output I think is pegged because there is a connection problem. I was looking at the trims while driving on the tablet screen and had been keeping an eye on the MTX-L display but may have missed the output from the WBO2 to the PCM was not working.

I'll check that later.

[bimbleuk]

Doh! I think the serial cable was separated when the PCM slid out of the strap I had holding it behind the dash. I remember it happening not long after starting the mapping last weekend. I just shoved the PCM back up. Annoying and a bit embarrassing so I reckon I'll be doing another session early Saturday morning.

I'd still be interested to know if the AutoVE values on B3605 are better for mapping using CALC.VET?

[joecar]

Ok, I confirm that your WO2LAM1 is pegged at 1.7.

B3605: the answer is yes/no/maybe.

B3618: it should be richer, set it to EQR 1.165 to be safer.

[bimbleuk]

Thanks for verifying my mistake!

I'll go back to the orginal B3605 values then as they worked OK before. I'll up B3618 for the mapping tomorrow.