what options or improvements are there for fuel systems over using an FMU?

 

With a MAP sensor. Look in my registry entry.

 

well hobie you have upgraded every possible option relating to fuel, except the fuel rail? thats all i can think of. what could possibly be limiting the amount of fuel your pumping in? another thing with my car is that it will stay to a good air fuel ratio if i (very) slowly apply the throttle, does yours? after all the stuff you have on your car you must be pulling your hair out. also pjal84 has a diffrent camshaft on his car from what i saw in a diffrent thread and it said he runs extremly rich ( but no turbo)

 

Well, I can tune my accel fuel trim, but it's a royal pain in the *** unless you're well versed in that sort of thing. My accel trim seems to be too lean as is, but I'm waiting on a new EPROM from AEM because mine got fried. Lovely stuff. I've got new gauges on order including a fuel pressure gauge. I think fuel pressure and my injector setup are the cause of all my woes. I'm going to start more or less from scratch though so hopefully I can iron this issue out altogether. Any other boosted Lancers having lean AFR issues related to fuel pressure (as opposed to injectors)?

 

its the computer. the afc doesnt work on the lancer computer, it only reads negative numbers. so no matter how much fuel u 'add' in the afc, the ecu isnt really adding no fuel at all. all of the fuel problems = ***** ecu.

 

I don't have a Lancer ECU though. That may answer some problems, but not all. Has it been confirmed that the AFC is completely non-functional?

 

This is a great topic. Since I've been thinking about getting a turbo, I've been wondering about all the up and downs of having a turbo and fuel management systems, but all the post I've been reading have been no help or I don't trust the info. So I just wanted to say kudos to u all.

 

are you saying as well that you don't trust the posts in this thread? or are you saying that this is the first one you do trust?

Fuel seems to be a nightmare on cars... my brothers mazda has fuel problems as well with his turbo. He's going to a second fuel rail to try and combat the problems. He also has a new piggyback and is going from an fmu to a pressure regulator now I believe. Hopefully it solves it!!

How does Greddy E-manage work? When you build fuel maps and so forth in that... is it just overriding the ECU? is it tricking the ECU? or is it really doing the injector controlling and so forth.

I'm curious too as to whether or not there is a reasonable way to take injector control completely away from the stock computer and run something that is turbo intelligent and make the fuel mixtures more precise that way.

 

Piggybacks can't override so far as I know. Everything I've ever read on them said they basically "intercepts and falsifies sensor information" sent to the ECU to obtain a desired result.

 

then a full standalone??? I'd assume that would have some of those capabilities.

 

well with the stock ecu one reason the afc doesnt work well from what i understand is because first the afc tells the ecu that more air is coming in. so the ecu changes what it needs to, but then the ecu also reads the o2 sensor to see if the change it made was correct, now its reading rich so it changes its map back a little to correct for the rich situation. so really the afc didnt do anything. so maybe you can just make something that always tells the ecu that the air fuel ratio is at the correct voltage, then you could tell it more air is coming in and it would check the o2 sensor to make sure its good and it would show the correct voltage so it would keep it that way

 

I may be your hero in like 3 weeks :-).

I have a lab class at my college where we have to design a final experiment for the semester. We have access to a dyno at school and I may get my brother's turboed MP3 up here and we will run dyno runs with varied a/f ratios, timing, boost, etc.

If you think of sequences that you are interested in .. pm me and I'll add them to our list!

Later.

Steve

 

The standalones don't need to be tricked. They need to be told what to do. You're essentially just programming every freakin' function your car knows (through its sensors).

Unlike a piggyback that intercepts voltages and sends a new one (altered by your user input) to the ECU, a standalone will take whatever voltage it's given (within certain predetermined sensor ranges) and do what you tell it to do with them.

You set up basic parameters such as O2 sensors, cam/crank sensor, VSS (vehicle speed sensor), AIT (air intake temp), coolant temp, MAF or MAP, and TPS (throttle position sensor) and from these you determine the vast majority of your engine and electrical functions. Basically the standalone will sit there and take readings all day long until you tell it what to do with them. i.e. engine revs > 400rpms and tps < 1% then you open the IAC (idle air control valve) to a certain percent, (and then on another map) and add this much fuel, thus getting the car to idle.

And yes, that's a bit simplified, but it gets the point across. You have no idea how much the ECU does for you and how much work goes into one until you go standalone. The EMS has become something I've learned to loathe, love, fear and respect.

 

You guys talk about real problems and real fixes. Most turbo/Fuel Management post are "this sucks" or "that sucks" or "I have (this) and it rocks", no meat.

 

quote:Has it been confirmed that the AFC is completely non-functional? (sorry dont know how to make the quote thingy work)
but i dont think that the afc is completly non functional. i notice on mine it changes the air fuel ratio for just a second, but then it gets swithed right back and it does it randomly so all of a sudden it will work but then the ecu reads the o2 sensor and it is too rich switches it back to the air fuel ratio it wants, thats why i think tricking the stock ecu and telling it that it has a good o2 sensor voltage then the afc might work better