Fast ez-efi 2.0 the elephant in the room

[howehot]

My Ez 1.0 multiport has been pretty reliable. I bought it fro Richard Nedbal and I had some minor questions that he handled for me. He is a pretty smart dude.

Have you ever put it on a dyno and got some real numbers? This is how I discovered my issues. Super lean at wot. The FAST programmer is slow and only reads to 14:1. I was at 19.5:1. FAST said factory injectors were to small. Bought 60lb units under their recommendation. Took it down to 16:1. The timing curve with the XIM is also problematic. Can't get the needed timing above 5700 rpm killing the top end. For drivability we sacrificed the top end for the midrange. FAST is very poor at trouble shooting their so called plug and play self learning EFI. I can it a retard.

I lost my first motor due to a bottom end failure that was never pinpointed. May have been the lean issue it was run under without my knowledge. Why doesn't FAST offer a handheld that will datalog with speed and accuracy. I think it's so you can't found out the extent of the issues.

[71RS/SS396]

Have you ever put it on a dyno and got some real numbers? This is how I discovered my issues. Super lean at wot. The FAST programmer is slow and only reads to 14:1. I was at 19.5:1. FAST said factory injectors were to small. Bought 60lb units under their recommendation. Took it down to 16:1. The timing curve with the XIM is also problematic. Can't get the needed timing above 5700 rpm killing the top end. For drivability we sacrificed the top end for the midrange. FAST is very poor at trouble shooting their so called plug and play self learning EFI. I can it a retard.

I lost my first motor due to a bottom end failure that was never pinpointed. May have been the lean issue it was run under without my knowledge. Why doesn't FAST offer a handheld that will datalog with speed and accuracy. I think it's so you can't found out the extent of the issues.

Dan, those 60 lb injectors are too big for your engine, 42 lb injectors should handle it just fine. The 60's could cause you some tuning issues at idle, just keep it in mind if you have problems. I'm still using the stock LS7 injector in mine although they are at the limit of duty cycle.

[old66tiger]

Real numbers? Like horsepower or AF ratios? No, most of my tuning comes from the street. We don't have too many chassis dynos around here and the ones that are, want to breed you for all that you got.

I have an Innovate LM-2 that is connected to a Speedhut in-dash wide band O-2 meter. The unit is calibrated and the wideband confirms that the EZ settings are just about dead nuts on. The FAST dashboard responds very quickly and I don't see much of a discrepancy. I also have data logging capabilities in the LM-2 which makes up for the lack of such with the FAST unit. IIRC, I have the FAST unit set it to 11.8 for WOT and when I hit the gas, it goes to 11.5 ish on the LM-2 and holds steady until I let off for a shift. My only complaint is that the EZ system bounces around too much at idle and there is no control for timing. Data logging would be nice, but the wideband in the dash gives me a pretty good idea what is going on. Much better than a carb.

I had a friend that had a Holley Avenger EFI system and that system was very poor at cold start and idle. He screwed around with that system for quite a bit and never got the bugs worked out before he finally sold it. He had wished he would have stuck with a carb. Have you noticed that the new terminator unit is now using a throttle body that is much like the FAST unit?

My experience with the FAST system is that it is very good at cold start and the AF targets are met very quickly under most operating conditions. Not sure what problem that you had, but if you were running that lean and the handheld was showing that you were running lean, there were other issues. If the hand held said you were fat when the engine was lean, then that is definitely a problem with the unit. IF you had been running that lean, the plugs would have been bright white and it should have pinged like a bag full of pin balls. I always pull plugs a couple times per year to look things over.

If I were to do it over, I would consider the Holley HP EFI. The other units don't seem to offer up much more than what I already have.

[Ron Sutton]

Real numbers? Like horsepower or AF ratios? No, most of my tuning comes from the street. We don't have too many chassis dynos around here and the ones that are, want to breed you for all that you got.

I hate when that happens.

[Drago]

This is an old thread but I have to share my issue. I have a 73 Challenger with a 408 Tri-Star Stroker and FAST EZ 2.0. Since new it had hesitation under load that would come and go. I tried different ECU's, FAST support, two different builders took a crack at it, countless hours of my own trying to diagnose it. It would run great for months, then it would show up and progressively get worse. Then you park it for a week and it runs great again. I ended up replacing / upgrading several items including the headers thinking there was a leak throwing the O2 sensor off (FAST support idea). I moved the fuel pump to the tank and rerouted it... two builders thought this was a good idea. Finally West Bend Dyno found a bad MAP sensor. Pic attached. It had a torn boot. Looks like it was torn upon initial assembly by FAST. The torn piece floating in the port causing intermittent blockage. Based on other posts and what West Bend Dyno shared... it appears FAST has designed a very difficult TB to assemble. Combine that with cheap Chinese sensors and you get broken or damaged MAP sensors that are hard to check and difficult to diagnose. We put a high quality Delphi sensor in and carefully reassembled. Unfortunately I believe all of these aftermarket EFI systems use the same cheap sensors. FAST has doubled down with a difficult to assemble and maintain design.