Cold start idle surge, massive timing pull, runs lean in open loop

[ShaneB]

Can anyone explain to me whats going on here? The log was too large of a file to upload so i needed to take the screenshot, I can try to take a shorter one another time if it would be more helpful. Anyway, at cold start it runs like 10% lean compared to commanded EQ for the first 70 seconds until it hits 90* ect. Theres also a slight surge in the very beginning as noted by the MAP line and slight RPM increase and decrease, and then it drops to between -15 and -25* timing after that for about 15 seconds. You can see its in closed loop for all of this. The only thing I changed in the tune is the CAGS tables for skip shift, nothing else. Only mod is a mamo ported throttle body. I've just never heard of people having this issue with ported TBs before, or I just havent read EVERY SINGLE forum yet lol. Any help would be appreciated and I can give more data if needed, I was logging damn near everything...

[mbray01]

if the the hump is removed from the throttle body, it will flow more air at idle, which on the gen5 ecms, will pull massive amounts of timing to correct(timing is immediate, therefore how the ecm uses first) it will need to be tuned properly to correct this. Its a little more involved than just simply adjusting the throttle body scalar. You can try using the throttle cleaned function in the scanner, but its unlikely to correct it very much.

Yes this is very common on ported throttle bodies, its not talked about there being issues because most people have it tuned at the same time as doing the throttle body, so the end user doesnt see an issue

[ShaneB]

Yeah I tried the clean function last night and it did the exact same thing this morning and when I went to grab lunch at work, and maybe even a little bit worse, and unfortunately I forgot my laptop this morning and didn't log those cold starts. So do you think adjusting the idle torque tables and tuning the maf/vve would fix the cold start?

[mbray01]

dialing in your airflow models will help, but most are going to be done in your idle settings, adjusting how the ecm controls the throttle body, you want it to pull the throttle blade closed, while still maintaining idle timing

[ShaneB]

Finally got around to re-installing the throttle body after setting up a flex sensor. Here's a log of the startup right after the install, and it was still not entirely cold. Also attached the stock file and whats in it now. I need help here, please

20-02-25 22-11-51.hplflex9ptb.hpt1LE stock.hpt

[ShaneB]

And a real cold start this morning. Long crank and it almost stalled on its own a few times. Seems like it runs the worst when it goes into cat warmup, should I just turn that off?

20-02-26 07-17-30.hpl