rummer

Very recently I got my car running but am not very happy with how it runs with the EZI Fast 2.0 EFI. It has not been transitioning well from cold engine to warmed up ( dies when you give it some throttle unless you do it very gently). I also backfires alot after coming off of throttle. At a carshow yesterday I got some feedback from some folks that had similar poor experiences with the same system. One fellow had problems to the point where it required an engine rebuild. My engine is a 455 stroked and bored to 495 with a comp cam, ported Edelbrock heads, and Mondello intake. Has anyone had similar issues with the Fast EFI and been able to solve them without wrecking a motor? Also has anyone used a different EFI system and had great results? It seems that the EZI Fast EFI likely works pretty good on motors closer to stock but my have issue adjusting fast enough to a moderately modified motor with a big cam and tougher timing needs.

cutlassefi

I've done dozens and dozens of Efi installs, about a half dozen that were Olds, including my own.
The reality is when you do just about ANY simple "self tuning" system it'll be pot luck at best. The only "self tuning" throttle body system out today that's worth a damn is the Holley Terminator. That's because it's very tunable and doesn't rely on an over simplified program.
But if you're serious about doing EFI on your particular combination, then do it the right way, multiport, with a capable controller, like an AEM or similar. In the end you'll be glad you did, I promise.

Bryan Burch

I use the non power-adder Fitech EFI 600hp kit on my 69 442, and it runs amazing. I've learned while following groups of fast, edelbrock and fitech, that each have their quirks. Most of the problems with any of the systems is related to install issues, timing issues, EMI issues, and O2 sensor issues. I can't claim to have had any issues, outside of the throttle position sensor set-up on the initial start-up. Took me 3 minutes to fix that and it hasn't hiccupped since. I can't offer much advice outside of this: Start over and verify everything is set up like FastEFI recommends.