In the summer its both. Im.having a heck of a time making it idle and work properly. The sheer amount of tables and modifiers that im not used to from obd1 is just insane. Almost tempted to buy hpt and let someone tune it for me
In the summer its both. Im.having a heck of a time making it idle and work properly. The sheer amount of tables and modifiers that im not used to from obd1 is just insane. Almost tempted to buy hpt and let someone tune it for me
1993 Lt1 24x torqhead swap
Tick performance cam.
Do you have a wide band? Have you tried running open loop?
Hp is nice, but not everything is always labeled correctly, or defined.
What does it do at idle?
No need to re-invent the wheel. But we can make it better
So i itially i used the factory Ls firebird calibration. All i did was adjust commanded idle rpm to reasonable levels for a cam. Started, took a bit, then idled fine around 11 afr. Too rich obviously. Didn't let it get up to temp so not sure if.my issue is else where, or self inflicted. But what it does is i adjusted base airflow based on hp tuners videos, and adjusted my injector flow, and now itll idle nice around 13.5 cold start, then after 30 seconds starts bucking really bad, afr jumps from stoich to 18, then eventually drops to 23 afr and will stumble out and die.
1993 Lt1 24x torqhead swap
Tick performance cam.
Sounds to me like the injector settings are wrong then when it goes closed loop it has way to much of a swing.
Are you sure the injector settings are correct for your fuel pressure?
Does that sound plausible to you?
No need to re-invent the wheel. But we can make it better
No this is open loop, i dont even have heated o2s yet.
1993 Lt1 24x torqhead swap
Tick performance cam.
Have you tried failing the MAF and dialing in the VE tables?Originally Posted by blakebird93
Is the commanded AFR stoich?
No need to re-invent the wheel. But we can make it better
Maf is failed yes, my car is a 93 and never had one so i didnt want to buy one. Plus ve makes more sense to me. I dont see commanded afr. Its gotta be some kind of after start decay or maybe its still trying to go closed loop. But even so, closed loop will see the unhooked o2s showing 450mv, so no fuel correction should be going on. For obd1i only ever had to crack the idle set screw open a turn, set base timing table (theres only 1) to 18, then adjusted idle ve. Done.
1993 Lt1 24x torqhead swap
Tick performance cam.
To run open loop correctly you need to disable closed loop.
There should be a table for the commanded ratio. In HP I think it's called open loop fuel air Ratio.
Values should be between something like 0.80 -1.10. And referenced to Engine temp, and vacuum kpa. I would change all to 1 at about 100deg F and above.
Minimum temp for closed loop set to max
There is another option for short term fuel trim in open loop. Make sure it's disabled
Might also set maximum and minimum fuel trims to 0
If it doesn't see O2 oculation, it can try to get it to. Obd2 doesn't like O2 signal stagnant.
That's what I would start with,
No need to re-invent the wheel. But we can make it better
What are you using for data logging?
Is it verified fuel trims at 0?
No need to re-invent the wheel. But we can make it better
Just a snap on scanner to check on things no actual logger yet. Trims are zero its open loop and they get reset after the flash.
1993 Lt1 24x torqhead swap
Tick performance cam.
Kinda hard to say where to go without a log, but there should be a read out for desired AFR eq ratio or lambda
No need to re-invent the wheel. But we can make it better
I found the open loop table you talked about. In that xdf its open loop commanded fuel. Everything looks normal no lean spots
1993 Lt1 24x torqhead swap
Tick performance cam.
So are you able to flash it, or do you have to use tools from work to flash?
No need to re-invent the wheel. But we can make it better
Here i am over Thinking stuff again... I had forced it speed density, did everything correct. Except one thing. I disabled the dtc processor for maf, not the mil only. Well if the maf codes are disabled, it never fails, then never goes into sd, and tries to use the maf even though i dont have one. So once afterstart decay timed out, it tried using the maf value (0hz cuz its not there) for fuel. Hence the max lean stalling. Fixed that and it idles fantastic and its not even dialed in the ve table yet. Man its always the little things.
1993 Lt1 24x torqhead swap
Tick performance cam.
Awesome. Glad you figured it out
Now you just need to be able to log it.
No need to re-invent the wheel. But we can make it better
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