First off I need to find an ECU wiring diagram for my 93'. For some reason the car will NOT run with the SAFC2 unplugged. My second question is what type of sensor should I use for it? If the car wont run without it I might as well tune it properly. The only mods on my car are a front mount intercooler, intake, and turbo back exhaust(no midpipe or cat). The car is running stock boost.
HELP! Shes runnin rich and idles funny!

 

http://mahjik.homestead.com/files/ho...ng_Diagram.zip

 

You sir are the man. Thank you

 

Ugh, the stock ecu is plenty rich for those mods....the SAFC really doesn't accomplish anything with FDs, because of how the stock ecu is set up to run the car.

 

While the SAFC isnt the best option for an FD being there are alot of aftermarket plug-and-play units available, coming from owning/building many FCs for the past ~6 years, the S-AFC is a very common mod for them. Im not as familiar with the fuel maps for FD, but on a FC is it not uncommon to pick up ~20+ RWHP with just fine tuning the fuel curve, and leaning out the top end, where a FC runs very rich. It can also be used to control larger injectors. This may not apply as much to FDs, and I think there are much better alternatives, but Im sure its not worthless.

As to the original posters question, you need to trace the wires from the S-AFC to where whoever installed them tapped into the stock wiring harness. There may be some shoddy wiring issues causing your problems.

 

Thank you for an actual answer. I would more than love to ditch the SAFC so that is why I required the ECU map. The problems that it is having(bucking, sparadic idle, etc..) I looked up and found that it could also be it was setup wrong. I wanted to know what sensor style.. karman, hot-wire, flap, or pressure... was correct for FD's.

 

AN FD doesnt use any airflow type sensors, its a MAP based system, so I would assume pressure type. I know you can run the SAFC from the boost sensor on FCs, but not sure how one would wire one up in a FD. I suggest calling Apexi and asking.

 

If you unplug the safc then you have to jumper the two pins (the ones that control the fuel;I can't remember what its called) otherwise it doesn't have a complete circuit and thats why its bucking upon acceleration. Trust me on this one as we had to do this on my brothers 300zxtt.

R.K.

 

Yep. The SuperAFC taps into the signal from the MAP sensor - with it unplugged, it's like that sensor is unplugged. That is THE main sensor to the ECU, and the car will either not run or run VERY poorly without it.

You can just re-connect the MAP sensor wire to bypass the SuperAFC. Or, if it's already in the car, might as well leave it there .

It is true the SuperAFC doesn't do that well on an FD. Since the fuel cut is determined from the MAP sensor, you really can't run more boost than stock properly, and most any mod on this car will give you more boost. They do work pretty well with chipped ECU's to let you fine-tune the fuel curve a bit, but that's really it.

Might be worth selling it to put money towards a PowerFC for your car . They're getting cheaper and cheaper, and it's one fantastic ECU.

Dale

 

Good info! I knew the SAFC would tap into that wire, but I didnt know that with the safc disconnected it would cause an open in that circuit.

 

Thanks for the killer info! I will be looking into this on Sunday to see what I can do. There is a local guy here who has an FC and we "plugged" it in to find out proper boost and temp measurements. I am deffinately going to upgrade to it but I'm sure with the mild mods I have now the stock ECU will work just fine...
When we unplugged the SAFC it would turn over and somtimes fire up and die so that does make a lot of sense. Thanks again for the info!