Cold start issues- Help needed

[1320bee]

Hi everyone. I've got a cold start issue with my Scat Pack after a camshaft swap. Car struggles to stay idling, and starts surging/dropping rpms until my oil temp reaches 120 degress. Any help would be greatly appreciated.

[Stoopalini]

I replied to your other thread, but looks like it was removed?

Is this a 392 Scat 1320 Drag Pack edition, with a 2.9 Whipple on top, running 14psi of boost?

If so, 14psi is a lot of boost for a stock 392 lower rotating assembly. Was any work done to the pistons, rods, crank, etc ... to beef it up to support boost?

In the other thread you stated injectors, and some other things, were swapped out and then the tune was updated to account for it. Who did the tune update for those things?

You also mentioned it went on a dyno in Feb/Mar of 2024. How did that go, and did that shop notice any issues in the log during the dyno session?

You have a lot of knock retard going on during that log, FYI.

It would also be helpful to others if you posted the OEM calibrations along with the current tun e you already posted.

[1320bee]

Yes, I have the 1320 Scat Pack with a Whipple 2.9L blower. I have many other mods, but to answer your question about the bottom end of my engine, all internals are forged. The injectors where upgraded to 1000cc injectors, and I entered the data that came with the injectors. The shop that did my tune made adjustments of course, and the dyno wasn't bad. I still had some cold start issues after the dyno, but it got worked out by the tuner. Now, I'm already into different territory because I did a phaser lock out with a Comp Cams Stage 2 Blower camshaft, with 1200cc fuel injectors and a dual fuel pump system with a fuel regulator and return line. And, yes, my posts and comments have been reset, not by my choice. What I posted now is my current situation, and I don't have the knowledge to correct the cold start issue.

[KanCer]

Perhaps not the issue but NN is on in that tune. With stock values/weights for a scat pack.

[DodgeBoy_8HP]

Did you try playing around with spark, airflow and PIDs?

It might help

[1320bee]

My O2 sensors are going crazy.....

[Dave401Redeye]

Hi everyone. I've got a cold start issue with my Scat Pack after a camshaft swap. Car struggles to stay idling, and starts surging/dropping rpms until my oil temp reaches 120 degress. Any help would be greatly appreciated.

I think you have to disable NN if you are not running a stock cam. Than you tune with VE. VE changes have no effect with NN enabled. Your throttle body airflow, small airflow and large airflow look way to big. I would put them back to stock to start tuning. Then reduce the throttle body airflow and the small airflow another 5 to 10% from .75-.90v cells up to the cell below max airflow. I would set axis on small desired throttle airflow to match the throttle body airflow axis. 0.0 0.02 0.10 0.15 0.20 0.35 0.50. also also match airflow on both tables. I did not see what fuel your are running at 14psi boost. It is aggressive if you are 91 to 93 oct. You can help idle with timing. base max timing is now at 2` it will idle better at 10, 12, 14 area. In min spark table and min start vs time table you have to put - values in idle area. To keep motor from surging the pcm retards timing to slow rpm or adds timing to raise rpm. Min spark torque reduction table needs -8, -9, -10 in idle area. I think there is a pathway to decent idle using tables i listed.

[1320bee]

Wow, that’s a lot of great information. I’ll turn NN off and attempt to make changes as you have suggested. However, I’m still going to need an experienced tuner, not a wanna be tuner who turned out to be just a consultant after being paid in full to get it where I would like it. I’m a beginner, so all of this is new to me, and I did get scammed for trusting the first person to offer his services. The guy may have some knowledge about tuning, but he’s not a professional tuner and has bad methods from some of his posts. I do appreciate your help and knowledge. Thank you, Dave401Redeye!

[N2speed]

definitely want to tune with SD and Disable ANN with that setup.

[1320bee]

I kept making adjustments during a cold start, but by the time I ran the attached data log, the engine was warmed up already. I don't know how a cold start will do with the tune.

[HaasExp]

The injectors where upgraded to 1000cc injectors, and I entered the data that came with the injectors.

Which injectors are these and do you have the supplied data to post up so we can check.
The LTFTs+STFTs are absolutely maxed out at -63.3% in your latest log at idle

[1320bee]

These are the Deastchwerks 16-MX-21-1200 fuel injectors. Any help would be greatly appreciated.

[HaasExp]

I corrected the injector characteristics for you based on the injector datasheet provided.
The rest of the tune obviously still needs a heap of work, but hopefully this should knock back them crazy negative fuel trims you had at idle a bit.
Base Tune-HE Inj Data.hpt

[1320bee]

Thank you very much HaasExp! I will post another log tomorrow morning. Again, I appreciate your help!

[1320bee]

Hi HassExp. I ran your tune with a data log, but my engine was already warmed up. I'll try another one in the morning. I did notice some engine shake, which I didn't have when running the pulse width injector table #3. All other tables caused excessive engine shake. I didn't check, but if table #3 is changed in any way, I'll get engine shake. I do appreciate your help!

[LilSick]

I didn't check, but if table #3 is changed in any way, I'll get engine shake.

what fuel are you running?

someone moved your FA limits to an extreme i have never attempted

why?

and why did you install 1200cc injector and leave start up pulse width stock?

you are drowning that thing

prolly washed the rings outta it

no tuner is gonna try to tune it without first seeing the results of a leak down test

[1320bee]

Seriously Don? I paid for tuning services, but after paying in full, all of a sudden the self proclaimed tuner says, “Well, I only consult. Sorry about the confusion”. What confusion? There was no confusion, only a flip flopper. Why even bother commenting? Just don’t please.

[Stoopalini]

Hi HassExp. I ran your tune with a data log, but my engine was already warmed up. I'll try another one in the morning. I did notice some engine shake, which I didn't have when running the pulse width injector table #3. All other tables caused excessive engine shake. I didn't check, but if table #3 is changed in any way, I'll get engine shake. I do appreciate your help!

Did you reset adaptives after loading HaasEXP's modifications?

If not, reset adaptives and take another log. Do a short drive though, not just idling like your last one.

[1320bee]

Hey Stoopalina. No, I didn’t reset my adaptives. However, I do have a member who is helping me with my tune, so at this moment, I’m going to stop posting logs out of respect for him. I appreciate every members input and help that has been offered. My Challenger does drive, but is not running at its maximum performance. I can’t do a true full WOT because of my transmission. It won’t allow me to do a full pull without going into Limp mode. However, my HP90 will be installed any day now. I will keep everyone posted on the progress of my Challenger. Thank you everyone!

[Stoopalini]

What's the part number for your TMAP sensor? The characterization data doesn't seem right, and will throw off your airflow model if it's not.