DSG87

I'm trying to figure out exactly what the issue is as to why I have a much more responsive throttle while the vehicle is warming up compared to after it is warm. Upon reviewing the monitors on tunerpro from some data log sessions, I've noticed that possibly the biggest difference is the way the spark advance (the pink and green lines) reacts when first started compared to once warm. I've included a couple snap shots of the charts for reference. Just curious if this looks normal or if anyone would have any suggestions for me. It seems odd to me that at first the dip in spark advance is much more dramatic but the response is quicker compared to later on the dip is much less dramatic before increasing yet it feels as though the response isn't as quick to react.

ULTM8Z

Is the car factory? Or modified?

I'm not an expert on the MAF cars by any means... but on the 90-92, my experience has been that seems GM leans things out too much with fueling vs coolant temp and fueling vs air temp (fueling includes power enrichment, accelerator enrichment, open loop, etc...basically everything related to fueling).

It results in what you're experiencing... a seemingly more powerful car when it's warming up than when it's fully warmed up, and the effect is even more pronounced when the air temps start climbing.

I had to undo a lot of that leaning out to keep the mixture right (as reported by my WB).

I also zeroed out the advance correction correction bias vs coolant temp. In 90-92, it's taking timing out at high coolant temps.

DSG87

I appreciate the response. The car is an 89 iroc 350. It has been mostly stock and the most I know about it is the engine has been just refreshed at some point in its life but nothing special. My grandfather had it for about 8 years and then I finally got the chance to get it from him last spring when it had been going through hard starting issues and major rough idling and running issues. I replaced the injectors with the bosch 3's and it was still a little funky but much improved. I then got in contact with a tuner who had me data log and send them to him and he'd adjust the chips accordingly until we got it to run almost perfect. Now it starts great, idles perfectly and runs excellent. I just have that throttle response issue that bugs me and I'd love nothing more than to get that resolved. I have read and understand that as it warms up it tends to run rich so the fuel delivery is basically much more aggressive and i was leaning towards the idea that this is the reason the response is better as it's first warming up but I wanted to be sure that the spark advance "curve" I'm seeing isn't the issue and is normal for a typical throttle response.