@tberg posted:Bryske,
Let me caution you about the Holley system. About 5 years ago when I was having my '72 refreshed, I couldn't wait to have fuel injection installed. The ritual of starting my car was such a pain in the rear, that I simply stopped driving it for years. I was deliriously happy the first time I just turned the key and she started up without a protest. That unbridled glee turned to terror when the car would get up to about 180*F, the f.i. would simply shut down leaving me stranded in some extremely dangerous situations. I would have to sit there for 15-20 minutes allowing it to cool off before it would run again and I could pull out of danger. This meant I would only drive the car in very cold temperatures and in Los Angeles, that isn't a normal occurance. I had two very trusted mechanics that I have used for decades, try and diagnose the problem to no avail. And Holley has not answered their phones since the beginning of the pandemic so getting tech support from them was impossible. Four months ago, I gave up and yanked the Holley fuel injection and replaced it with a Edelbrock carb and yes there is still a ritual starting the car, but I can do it without getting out of the car, pulling the air cleaner and dumping gas in the carb (which is what I did for the better part of 15 years. And yes, it doesn't run quite as smoothly but I have been driving it now for several months every weekend, and have not had an incident since. And just know that you're not going to get any help from Holley right now. We tried dozens of times over a three month period, never once including an 8 hour stint of being on hold. I would look into other systems that actually provide customer support.
It sounds like the problem that you had with your Holley EFI system could be a fuel enrichment table adjustment. My FAST XFI 2.05 system can enrich or lean the fuel air ratio at a given water operating temperature. I am quite sure that Holley would have the same feature. If the table is going too far one way or the other, then it could very well shut the engine down. Are you getting into the EFI program and looking for any fault codes? These systems have that ability, but in most cases you have to attach a laptop to them.
I agree that customer support with most of these EFI companies is not always good and that adds to the frustration. When you say that you have used good auto mechanics, are they experienced with aftermarket EFI systems and tuning them? I have stressed this before, but the shops that do these EFI conversions have people that know the aftermarket programs better than anyone.