525 ls3

[Jabbott]

So I am kinda of embarrassed to say that I may have bitten off more than I can chew with this one. I installed a 525 engine in a 03 auto C5. All of my steady state tables are close to lambda 1, depending on day they may venture 2% right now. My timing tables are modified for the 525 as well as my fuel models and TB area conversion table using the silver blade 90. Car idles, but it will not stabilize after throttle, either lightly pressing on it or revving it up. I have gone up and down on my idle air tables and tf tables. I have gone up and down on adaptive idle tables, to the point of removing them to see if even that would work. Nothing really seems to make much difference. I even installed a gold blade 90 and really no difference, removed a screw from the blade to let some air in and again nothing, just drawing a straws. So the only thing I notice is that my idle TP position is 17%, when I rev the motor it drops to 9-11 and will not recover from that. I am running 13 degrees at idle so plenty for additional torque but it does not save it fast enough. So I guess my question is has anyone successfully made a 6.2L with a ASA cam run ok using a LS1B or PO1 ECM? This cam has never been an issue for me on a E38 or E67 and figured I would get it dialed quickly but that has not been the case.

[jaydubb71]

Is this the LSX 376/525 crate engine? P01? IAC reset? 17% TPS is waaaaaaaay too much. Does the IAC work? SD or MAF? Post tune file...

[Jabbott]

Well because you can't set where the TPS runs, that is where it is stable. Yes, LSX 376, PO1 ECM, there is no IAC motor, its' part of the 90mm tb. This is a blended VE/MAF calibration. I can't adjust the 17% that is where it is maintain my idle air table of 18 g/s on idle. That is at 850 RPM which it idles at and it is stable at that point. The issue is that no matter how much Throttle follower or really anything that has been done up to this point, if you rev the motor it will sputter and die pretty quick. I have added some timing to my base and it helps but still not enough. If I could set the min tps angle to 17 or say 15% that would fix the issue. When you rev and the rpms come back down, my TPS is coming down to 9% and it can't recover from that. SO my question is, who has a P01 ECU running a LSX 376/525 crate motor. I have had these engine in many E38 and E67's with no issue, but this seem to be really testing me.

[kevin87turbot]

If you'll post your tune and a datalog, I'll be glad to take a look.

[jaydubb71]

I missed the part about this being a Vette... Post tune and log file?

[mjm350]

I have a LS3/480hp crate motor in a 2001 Z06. Not the same but might get you in the right direction. Idle manners are pretty good with a little lope. Here's my tune if you want to take a look.

[Jabbott]

Thank you mjm350. I did try adapting your tables into my calibration and it does not want to start. Only a couple of tables looked different and I didn't modify my TB tables. I am going to go back and check for any mechanical issue in the morning once it cools down and see if something is a miss. It ran great on the dyno once I got the MAF curve and VE tables done. With some time changes the car made 450 to the wheels, it just will not idle. If you start and just let it run on it's on it is fine, its not until you give anything on throttle that it just wants to die. I'm getting some really odd data out of my WB right now so I also need to see what is generating that. I can go from showing a lambda of 1.23 to stop turning the car off and restarting to showing a lambda of .98 or sometimes even richer. There is something else going on in the background that I am not catching but tomorrow is a new day. I am using a AFM1500 WB.