cold start low rpm and sometimes dies

[orion4096]

ls1 01 camaro engine swap
tsp prc stage2.5 5.3l heads
tsp 228r (228/228) 114 lsa
fast 92mm
bluemaxx tb
42# @ 43.5 psi delphi injectors
had a 100 wetshot, but that's been removed

The problem is basically that on cold start the engine starts up fine and then the rpm drops until it dies (sometimes it recovers and is able to idle). You can see this happening in the attached log when I start it the first time. The second time I crank it the rpms drop, but it's able to recover until I shut it down.

First off, I don't have a wideband installed yet. That might be enough reason to tell me to go away, but I figured it's worth trying to get help with this cold start problem to help me learn a little about hptuners and ls tuning. I bought the car and with the engine already swapped in and the attached tune. From the reading I've done on this forum, the tune should just be completely redone with a proper OFLA table, closed loop, better idle speed table, a proper air mass (VE) table, etc. I'm working on getting exhaust redone for better ground clearance so I can road race the car and don't want to retune it before that.

The things I see in the log that might be the cause:
- Lean NB O2 values on startup. Maybe this in an artifact of just starting and these should be ignored.
- Low timing advance when the car is started for the first time.
- No change to RAF under 133 ECT... I saw this in the tune.

My cfg is the default which is most likely missing idle related things. Should I grab the idle.cfg in the sticky and get that data tomorrow morning?

Is it a waste of time figuring this out with this tune or without a wideband installed?

[WS6FirebirdTA00]

http://www.hptuners.com/forum/showth...hlight=posting

[orion4096]

I assumed you meant you wanted a log with more useful info. It's attached here. The tune is open loop right now so fuel trims aren't very interesting.

[WS6FirebirdTA00]

Doesn't matter, the tune is needed if you want more help.

[orion4096]

I already attached the tune in my first post 3 days ago.

[Frost]

Not the most useful of logs, but it's something. Notice your LTIT is quite negative from learning that way when warm. Now, it's acting to remove idle airflow when cold.

Here are some items to look at: It's dead lean at startup because your OLFA is set to 1.0 at all ECTs (?) It's ok to set 176 and above to 1.0, but not beneath that. That is why the car is lean. The MAF table is completely stock. All injector parameters minus IFR are still stock and the IFR looks numerically low at a glance. Your idle airflow is the same value from 133degF-up; you know that's not the result of logging. All of your startup airflow tables are stock including the delays (to my eye anyway, and this is hurting startup like the OLFA) and you are commanding an 1100 idle (??) from bottom to top of the temperature range. Your High and Low octane tables are the same and look kind of like some older LS1 edit tables with the 'spark shelves'. Your Max KR in PE has been zero'd (!!).

That's what I see while I sip my coffee

[orion4096]

Thanks. Yes, the previous owner of the car unfortunately payed someone for this tune. The NB O2 values go rich before it dies in the first log. Maybe that's caused by the car stalling. Sounds like I should buy a wideband and start over rather than bandaiding cold start idle.

[transamdroptp08]

Thanks. Yes, the previous owner of the car unfortunately payed someone for this tune. The NB O2 values go rich before it dies in the first log. Maybe that's caused by the car stalling. Sounds like I should buy a wideband and start over rather than bandaiding cold start idle.

That would be a wise choice.

[Frost]

Thanks. Yes, the previous owner of the car unfortunately payed someone for this tune. The NB O2 values go rich before it dies in the first log. Maybe that's caused by the car stalling. Sounds like I should buy a wideband and start over rather than bandaiding cold start idle.

They are only rich during the first second which is first fire and they immediately fall off. If you even just set the OLFA back to stock and add some startup airflow it'll most likely start as it should.

[orion4096]

You were right. I copied in the OLFA table up to 170 degrees and added 1.0 to the air flow table down low and it started just fine. I then drove the car to the (steady-state) dyno and had it all redone and closed loop enabled.

Thanks for the help.