Hi guys/gals,
This is my first time posting here. I've searched for an answer but not sure if what I've come across will address my issue.
I have a 2015 chevy ss sedan with a LSA blower, fore fuel system (dual pump return style kit), etc. About two months ago, I had my tuner make some revisions to my tune, which included making some adjustments to the cold start. After picking up the car, it didn't have any issues with cold starts with e-85 from the local sunoco gas station which was around 75%. There is a company in my town that offers their "performance blend e-85" which I've used in the past a couple of times without any issue. After running out of the sunoco e-85, I had that company come fill up my car with their performance e-85. Their ethanol/alcohol content is at 86-87%, about 10% higher than what I had. Ever since my car was filled up with that fuel, it won't fire up on the first cold start attempt but always on the second attempt right after, and any time after that within the same day. However, if I go to start it the next day, it again won't start on the first attempt but on the second attempt, no problem. Here is the weird part. If I go to start the car after it's been sitting over night, like I said it won't start on the first attempt, however, if I don't attempt the second start right after but let it sit again till the next morning, it starts right up!!! Almost, like it knows the first attempt was the day before! This has me stumped!
I've tried adjusting the Cranking VE table by applying +10%, -10%, -15% (car wouldn't even start with this much removed), and no luck.
Fuel pressure is 60+ psi when cranking, so I don't think it's a fuel pressure issue. I have a return-style fuel system and as soon as the pump(s) turn off, the pressure bleeds but immediately pressurizes when the pump(s) turn on. It has always done this and never really had a cold start issue before until now.
I have a feeling that if I were to pump e-85 from my local sunoco gas station, it would go back to starting up on the first attempt like before. I haven't tried that yet since I was waiting to run out of this "performance e-85".
Has anyone come across this before? Could it be tune related or something else going on with my car?
Attached is the tune and a log file. Thanks in advance!