Re: 90 hp ficht - stumbling
You are confused about how the injectors are programmed. They go from extremely lean up to ~ 2K RPM, then much richer mixture above that for cooling, at least that is how they work in E-Tecs, which I assume is similar in Ficht's. Don't know about Ficht injectors, but E-Tec injectors are not field service and some are not serviceable at all.
Are you telling us that all Ficht injectors have exactly the same flow characteristics and there are no unique injector coefficients at all?
I recall reading about the reason why the injectors were individually serialized and characterized. The original FICHT injectors were not spray pattern calibrated, causing carbon build-up at low RPM. So I think they went to indexing the plugs (hex key on 2000 models and thereafter) and individually programming the injectors to reduce carbon build-up.
I think this works for the first "x" hours of use, afterwhich, the computer has no way of knowing how to compensate for clogs, and performance losses associated with use. There is very little closed loop feedback in the EMM system for injectors. It merely turns on the switch and assumes the injectors turn on. I use the software myself and am not that impressed; although it is pretty cool for its time.
Given the pre-2000 FICHT don't have performance problems using non-calibrated injectors AND virtually no other fuel injection systems individually custom calibrate fuel injectors; I think this is a bunch of hogwash for injectors that are 10 years old (like mine). Everytime I see development engineers measure 2x4's with micrometers, I am skeptical of its long term viability. Just my opinion. It's ludicrous that there are over $2400 worth of injectors on my 90HP FICHT.
Back to your issue Whaler82..... One way to troubleshoot if the fuel injector is working or not is to individually unplug the sparkplug wires one at a time while it's idling. If it doesn't drop RPM, it may be the culprit. If you can get to 5200rmp, I think they're all firing. When one of mine went out (1 of 4 injectors), I couldn't get above 3500rpm. The other way is using the s/w, which turns it on and you listen for clicks to verify it's working. The s/w isn't all that impressive for fuel injection issues; it only gives you the ability to turn injectors on and off. this tells you nothing about how they're performing relative to the factory spray calibrations.
I'm sure some will find fault in my reasoning, but my 16 yrs of engineering experience help form some of my strong opinions. good luck, keep us updated.
Tim
