SD Lean warm start possible FIX.

[Ben Charles]

This may be a solution to OLSD lean warm start.

This table is setup to start time when the engine has been turned off.

In the table below I modded the 111-154 temp areas to increase fuel (table is an adder, which works with the OLFA I believe) up to 7,200 seconds which equals 2 hours. So after shutting the car down within two hours at 111-154 temps the ECU will add fuel. My car operates at 178-185 roughly warmed up so after about 5 minutes of running, it will leave the 111-154 cells and stop adding fuel. The table goes up to 28,800 seconds which equals 8 hours, but warm restart is only effected within a 2 hour time frame mainly.

THIS SHOULD FIX OLSD Lean restarts IMO. I need to play with it to confirm (possibly either add more fuel or subtract some, depending on readout). The table shows freezing condition a the base in 3 cells? Not sure on why?

Opinions?

[Sam88gta1]

Why not just add a small value to the OLFA table?

[mecanicman]

Look at the posts by EC Tune

http://www.hptuners.com/forum/showth...8776#post78776

[Ben Charles]

I have messed with the OLFA table ALOT. I am actually commanded 1.09=13.47 AFR and I still get 11-12's COLD start AFR. Even changed it to .975=15.06 AFR still didn't change AFR (in fact didn't even want to run till I changed it back) Starting to have little faith in the OFLA table. Best just to set it up close to what GM did and leave it, then command stoich at operating temps.

mecanicman I have played with those settings before (earlier tune) and it seemed to make the car run worst? I may try it again, but I am wondering if anyone has messed with this table. In a sense this is basically what its designed for.

[Sam88gta1]

I have messed with the OLFA table ALOT. I am actually commanded 1.09=13.47 AFR and I still get 11-12's COLD start AFR. Even changed it to .975=15.06 AFR still didn't change AFR (in fact didn't even want to run till I changed it back) Starting to have little faith in the OFLA table. Best just to set it up close to what GM did and leave it, then command stoich at operating temps.

mecanicman I have played with those settings before (earlier tune) and it seemed to make the car run worst? I may try it again, but I am wondering if anyone has messed with this table. In a sense this is basically what its designed for.

OLFA adds to the current VE table at that operating temp. You cant command 1.09 and expect 13.47. If you command a value of 1.09 you are adding 1.09 to the a/f ratio of the VE table in that map range. OLFA only adds to the startup a/f. I believe it runs off of that added value for 10-12 seconds then returns back to the VE table. This is the table I use to add startup fuel to SD boosted files. Has worked fine for me many times even in the 105 degree Texas heat.

How lean is your start up now? I usually shoot for a 13.8:1 - 14.8:1 start up depending on the combination.

[Ben Charles]

Thanks for the info Sam, seems like once I get my Idle (warmed up engine) VE table correct, this will correct my COLD start AFR?

My COLD start AFR is 11-12 AFR. But my Warm restart stays lean, so thats why I thought the hotsoak table could possible add fuel to get the AFR back in line or at least till operating temps are hit again.

[Sam88gta1]

Thanks for the info Sam, seems like once I get my Idle (warmed up engine) VE table correct, this will correct my COLD start AFR?

My COLD start AFR is 11-12 AFR. But my Warm restart stays lean, so thats why I thought the hotsoak table could possible add fuel to get the AFR back in line or at least till operating temps are hit again.

How lean is the warm start? What is your IAT on warm starts?
What is your afr at operating temp?

[Ben Charles]

Lean warm start maxes out my NGK WB at 16.00 AFR (probably much leaner).

IAT on cold starts are 88-91 in 100 degree weather. Temps raise slowly to 100-105, hot restarts (few minutes) they are around 95-100.

Commanded AFR at operating temps are around 13-14 AFR, but turn lean after driving.

Here is my first SD drive (down the road and back), here is my config too so you can see data like me.