norcalairman

So I'm looking at swapping my '92 3vze AFM for a 7mge AFM. From what I've read, you have to adjust the mixture because you will be running to lean. What if you replaced your injectors at the same time for more fuel? As I understand it, the ECU just gets a certain amount of voltage from the AFM, which it computes to opening the injectors for a specific amount of time. If you are now allowing more air at the same voltage (which is why you have to adjust the mixture) why not just increase the amount of fuel being provided at the same time? Is there a reason this wouldn't work? If someone were going to try it, what injectors would be the best bet?

norcalairman

Well, I guess I'm just gonna have to wing it. I'll let y'all know if something explodes!

4wd4fun

its not that your allowing more air for a afm voltage, but different afm voltage for the same amount of air- think it's the trottle that controls air and the afm only measures how much. the ecu uses the afm and throttle position to figure out how much air is moving and thus how much fuel is needed.

bigger injectors will squirt more fuel per pulse and if the extra air isn't there, which it won't be due to the throttle plate, you'll run rich, hence why youneed to adjust the afm to compensate the fuel mixture.

it's not just the afm and throttle position that teh ecu uses. theres a temp sensor in the afm so the ecu can compute air density and a coolant sensor too. if you were going to use an aftermarket injecton systme like SDS or megasquirt your idea of bigger injectors could make sense but since youre not i see you in to lots of tweaking to get it running better than before over all rpms

norcalairman

Well with an aftermarket ignition system, I wouldn't need bigger injectors unless I was going to turbo it. I could just map how much fuel to provide. Unless of course I reach their limit, which I doubt I would without drastic modifications.

Thanks for the info though, that could have been a costly and fruitless experiment.