Is it possible to keep the stock ECM to control the ignition and torque converter lockup as well as input for my speedo and use a fast ez fuel system for air and fuel? I know the first thought is why?, but i just want to know if it's possible. The stock system is limited and the fast system uses a wide band o2 and has excellent reviews. It's also simple and tunes itself with no laptop. The stock system is finicky and periodically problematic.

 

So are you asking if you can have a stand alone fuel management system? If so then yes. Also while self tuning is cool, it's only as good as the stuff you put into it, if that. If you really want a real tune then you should learn to do it yourself or have a pro do it for you.

 

I dont think the speedo needs the ECM.

 

The speedo is electronic and works off of the vss signal from the computer. Also, the point of running the ez fuel system is so i don't have to get a pro to tune. There are'nt many people who can tune where i live and this system tunes itself and is very reliable. I don't know how to even begin tuning the stock ecm and the fast system uses a wide band o2 and does'nt even require a laptop. Any future changes to the engine and it's tuned in minutes.

 

I'm going to try and explain better what i'm looking to do and maybe someone can chime in and help. Basically, i am running a 383 first fuel setup. I understand the stock ECM controls spark timing, fuel injectors and Idle air. The computer also handles the vss signal for electronic speedo and contains the vats system as well as Torque lock up. Can the stock computer still control the ignition timing, torque converter lock up and vss signal without being plugged in to the injectors and other sensors required for fuel injection? Will the car crank over and start if the air and fuel is controlled by a separate system? I'm not talking piggy back, but independent setup like the fast ez system. fuel pump should still run right? Anything else i might be forgetting?

 

I'm not 100% sure on this (and someone can correct me if I'm wrong) but I don't think thats possible. Mainly because the ecm would need ALL the inputs from the engine for everything to work in harmony. There might be a way where you can get your ecm reflashed or redone so it'll work the timing off the rpms and temp, but if you're doing that, then you might aswell just tune the original ecm to your liking...

 

Hey 73,

I responded to your other post about EZ-EFI and I want to weigh in here too. I know what you're talking about as regards to tuning. I don't want to spend $150 a pop to have my chip reflashed every time I do an upgrade; I also think the stock computer is too finicky to get a real good tune. I'd spend the $900 in a heartbeat if I could get the answers to my questions, like you and my computer problems would be solved forever.

I doubt very seriously we can use 2 computesr as one computer needs all the inputs/sensors to properly control all the engine events. I laid out some questions that I'm going to email FAST, please add any issues you'd like me to address.

https://www.thirdgen.org/forums/dfi-...ml#post4434863

For what it's worth, and I'm no expert, Chevy HiPer did an article on this system in the last issue. The guy on the dyno said his carb'd setup made equal power with the EZEFi rig. Only it oook his EZ rig 5 minutes to get it right and he an hour to self tune. I too do not want to spend the time or money to learn how to burn and tune. My engine combinations may change over time and I do not want to have to spend the cash for a reflash when there's a proven system (proven in a magazine anywho-and it sounds pretty damm good to me) that will take the guess work out of it all.

 

thanks for the replies. I may just run the ez efi and go with a conventional ready to run distributor. I've used the ready to run distributors before as they don't need an external ignition box and they've always performed well. I can use one of the aftermarket wiring kits for the converter lock up. The fast ez setup can just concentrate on air fuel. From what i've researched, the system is easy, simple and self sufficient. Wideband o2 makes it a no brainer, i have no interest in tackling the stock ECU and whatever that may bring. I would'nt have to do anything for future mods either. My only question is about the stock pump operation and starting the car. Can i start the car without the computer? I also have the stupid vats system, how will that be affected?