starting help

[keithmcw]

I'm new to HPtuners and learning as I go. I've been scrolling the forums and have learned a ton of information, Thank you!!

I have a friend showing me the ropes and even helped with some dyno tuning. Problem is that since the dyno I can't get the vehicle to start well at all. When i can get it started and warmed up it runs pretty good for the most part. high rpm stuff definitely seems spot on. Pretty frustrating to not get it started or idling though.

I've tried fooling with a few parameters (idle air, PE,...) but I feel like I'm stabbing in the dark a little. Seems like it might be temp related as it's started getting colder lately.

so here's what happens:

cold start first try it will catch for a second then die immediately. On any follow up attempts it will have an extended crank then do the same thing. If I throttle it a little i can get it to catch and run if I hold it to 1500 or so. but it will die immediately after releasing the throttle. seems super rich and a lot of smoke when it does catch but I think that might be misleading and just be leftovers from start attempts.

After it's warmed up it will start normal each time.

Here's the build: 6.0 with a TBSS intake and 90mm sniper intake. 50# injectors #12613412. BTR stage 2 cam 227/235. Currently tuned on speed density.

Any advice or a direction would be welcome

[blindsquirrel]

Wrong injector data. Flow Rate is set up for returnless, but Offset is set up for a return system.

[keithmcw]

thank you so much for taking a look.

I had a feeling that data may have been wrong. I had the ecm flashed with what supposed to be a baseline from the same place i got the harness. turned out to be a massive headache. long story short I never trusted the injector data. anyhow I found what i believe is the correct spreadsheet and made some changes. does this look more correct for a returnless system?

[blindsquirrel]

My sample files with that injector# have slightly different numbers in the offset table, but not by much. Like 0.02 or less difference. It's at least in the correct format now.

[keithmcw]

Awesome, thanks. I’ll flash that and see what happens.

[keithmcw]

Well I updated that table. didn't seem to make any difference with the starting though. Any other thoughts out there?

[leciphern]

Just out of curiosity, and it may not make one bit of difference to your original query, why is this edited like this?
Screenshot 2021-10-20 135007.jpg

[2xLS1]

Just out of curiosity, and it may not make one bit of difference to your original query, why is this edited like this?
Screenshot 2021-10-20 135007.jpg

Because some tuners are morons.

[keithmcw]

Because some tuners are morons.

Well thanks for the insult... Perhaps some tuners are just learning and make mistakes! This is the corrected map, thanks for bringing the error to my attention.

Untitled.jpg

[2xLS1]

Don't know how that insulted you. You said you had a friend showing you the ropes. If he did that he shouldn't be showing anyone anything.

[keithmcw]

He did not, I’d did accidentally.

[2xLS1]

So you did it then ask why it's edited like this. OK.

[Matt Vardaman]

So you did it then ask why it's edited like this. OK.

The OP accidentally messed it up, a different person asked why.

[Matt Vardaman]

You have your idle rpm in gear higher than your park/neutral, which is backwards. Also Idle base airflow needs work. I'll give you a couple tunes to use as compare files that might help you get it figured out. 10-19-21 2002 Tahoe Flex add spark to alcohol mod.hpt1999 Silverado 2500 IDLE change2.hpt


The tune files are from the trucks in my signature. The first one is a 5.3 and has the same injectors as yours, but the cam is smaller. The second one is cam only 6.0 2500.

[keithmcw]

You have your idle rpm in gear higher than your park/neutral, which is backwards. Also Idle base airflow needs work. I'll give you a couple tunes to use as compare files that might help you get it figured out. 10-19-21 2002 Tahoe Flex add spark to alcohol mod.hpt1999 Silverado 2500 IDLE change2.hpt


The tune files are from the trucks in my signature. The first one is a 5.3 and has the same injectors as yours, but the cam is smaller. The second one is cam only 6.0 2500.

Thanks for the feedback! I have reworked my idle RPM thanks for pointing that out. I took a look at the idle air, I agree mine needs a little work. That's something I keep playing with and I seem to have trouble getting it dialed.