Fuel Issues, SAFC II tunning Options

[94silverbullet]

For fuel I have the walboro 255 hp, the supra 440cc injectors and I'm tunning with the SAFCII. What size were the stock injectors? Why when I'm in low throttle loop (actually idling) and set the SAFC II to -50% am I still at 10.3 to 1 A/F ratio?
I brought it to get it tunned today and the guy wouldn't touch it because it will not even idle at above even an 11?
Please help me out; I need my car for daily driving in the summer and I will only have a week to work on it before I start my summer internship.
Thanks for the help,
Derek

[d0w0rkS0n]

its teh same with me. i went even bigger and got the rx-7 460cc. pulled out -50% at idle and im still running rich as hell! im starting to worry about my piston rings.

[hurley97]

d0w0rks0n, your problem is because 460cc injectors are WAYY too big for the 7A. The stock injector size IIRC is about 172cc or 192cc. Somewhere in the 300-400cc range is appropriate for the turbo 7A, anything more than 400cc is going to be very hard to tune properly. My 315s were ok with the SAFC, once I moved to the 370cc injectors I couldn't tune it right with the SAFC and had to upgrade that as well.

As for the original poster, I have no idea what engine you're talking about but if its also a 7AFTE then your injectors are too big also, if its a 5SFTE the size is ok and its probably an issue with your method of fuel management and/or something not hooked up right or something, any other engine, I have no idea.

[d0w0rkS0n]

d0w0rks0n, your problem is because 460cc injectors are WAYY too big for the 7A.

oh i know.. i found that out after everything was already done. i think ima get new ones and retune the car.

[_Jim_]

If you are talking 5sfte, it sounds like your map sensor is shot.

[94silverbullet]

If you are talking 5sfte, it sounds like your map sensor is shot.

yeah 5sfte, do you have any clue what pressure readouts I should be gettin off the safc 2?
when the car is off my stock map sensor reads like +.49kg/cm^2, but when I swap it out and put in the 2 bar reads like -33mmHg when the cars off. Id rather not have to spend another 360$ to try it out

[presure2]

its teh same with me. i went even bigger and got the rx-7 460cc. pulled out -50% at idle and im still running rich as hell! im starting to worry about my piston rings.

460's are WAYYY too big for a 7a.
they are borderline too big for a 5s on the stock ecu.

to the op:
sounds like a map sensor, or initial setting issue.

[FunkySR]

460 is overkill. I'm still running 315's on my 7AFTE and AEM FIC. no problems and enough for 10psi.

[laff09]

If you are talking 5sfte, it sounds like your map sensor is shot.

yeah 5sfte

Not a 7afte. read people.

[94silverbullet]

Not a 7afte. read people.

That's what I was thinking haha...
all the initial setting should be correct: 4 cylinder, throttle is the up arrow, I'm on pressure, in 1 out 1... I set the ne pt to 800 so it would be closer to the the stock idle of 750, and put low throttle to -20% which is what I had recommended to me...

so assuming those are right, it's almost certainly something in between the the map sensor, wiring for the map sensor and the ecu correct?

5s by the way ; )

[presure2]

i know you have a 5s, my earlier post was directed at the guy who posted with a 7a.

those 440s your using...are you sure they are high impedance?
the only supra 440s i know of are low impedance.
you can test them right on the car with a multimeter set to ohms.
low will be under 5ohms. high will be 12-16ohms.

[Consynx]

What Manny said

I hope you are also giving your O2 sensor enough time to heat up/driving the car for a while.

But if they are the right impedance, and the O2 sensor has had time to work, then I'd get a fpr till you figure out what is causing this.

[Smaay]

the non turbo Supra 440 should be high impeadance. its the turbo 550 that are low. correct me if im wrong

This post has been edited by Smaay: Jun 16, 2009 - 3:58 PM

[Consynx]

i know the 550s are low, and the 1jz 380ccs are high.
dunno the 440s.

[94silverbullet]

I know its been a while, but I finally got a multimeter, they are low impedance (the supra 440cc's)... Can i still use these injectors if I put a 10 ohm 10 watt resistor on each wire. I believe the re3sistor can go on either wire of the injector correct?
The impudence will actually prevent the SAFC II from pulling fuel?

[presure2]

I know its been a while, but I finally got a multimeter, they are low impedance (the supra 440cc's)... Can i still use these injectors if I put a 10 ohm 10 watt resistor on each wire. I believe the re3sistor can go on either wire of the injector correct?
The impudence will actually prevent the SAFC II from pulling fuel?

im sure a google search could prolly give you the answer to that for sure. (im not sure) cause im sure the honda crowd has been down that road.
i know you can use a 3sgte resistor pack wired in, i've seen that on one of the boards, i cant remember which one it was on.

[qatar11]

I know its been a while, but I finally got a multimeter, they are low impedance (the supra 440cc's)... Can i still use these injectors if I put a 10 ohm 10 watt resistor on each wire. I believe the re3sistor can go on either wire of the injector correct?
The impudence will actually prevent the SAFC II from pulling fuel?

This should work... you are basically creating your own resistor block..

[boosted185]

I know its been a while, but I finally got a multimeter, they are low impedance (the supra 440cc's)... Can i still use these injectors if I put a 10 ohm 10 watt resistor on each wire. I believe the re3sistor can go on either wire of the injector correct?
The impudence will actually prevent the SAFC II from pulling fuel?

im sure a google search could prolly give you the answer to that for sure. (im not sure) cause im sure the honda crowd has been down that road.
i know you can use a 3sgte resistor pack wired in, i've seen that on one of the boards, i cant remember which one it was on.

MANNY- Yeah, the Honda guys wire in a resistor box, mostly when using the DSM injectors. However, the OBD-1 Honda harnesses already have a pre-pinned plug that you can almost literally PLUG the resistor box into.

To the OP, I don't know if just adding a resistor in the circut would solve your problem or not, but you could try it, and if it works, POST IT UP so others know that it DOES work!!!!

[94silverbullet]

MANNY- Yeah, the Honda guys wire in a resistor box, mostly when using the DSM injectors. However, the OBD-1 Honda harnesses already have a pre-pinned plug that you can almost literally PLUG the resistor box into.

To the OP, I don't know if just adding a resistor in the circut would solve your problem or not, but you could try it, and if it works, POST IT UP so others know that it DOES work!!!!

I wired the 4 resistors (10watt, 10ohm) into pins 11, 12, 24, and 25 about 3 inches away from the ecu... Still runs like a pos. any thoughts on why that didn't work? I'm thinking of moving the resistors under the hood in the engine bay (the temperature has no effect on the resistors) but I dont see much of a difference electrically to justify the switch.... thgoughts?

I can find it eventually I'm sure, but do you know or have any info on that resistor box for the obd 1 harness/ plug that they use? I don't know too much about electrical.

[boosted185]

MANNY- Yeah, the Honda guys wire in a resistor box, mostly when using the DSM injectors. However, the OBD-1 Honda harnesses already have a pre-pinned plug that you can almost literally PLUG the resistor box into.

To the OP, I don't know if just adding a resistor in the circut would solve your problem or not, but you could try it, and if it works, POST IT UP so others know that it DOES work!!!!

I wired the 4 resistors (10watt, 10ohm) into pins 11, 12, 24, and 25 about 3 inches away from the ecu... Still runs like a pos. any thoughts on why that didn't work? I'm thinking of moving the resistors under the hood in the engine bay (the temperature has no effect on the resistors) but I dont see much of a difference electrically to justify the switch.... thgoughts?

I can find it eventually I'm sure, but do you know or have any info on that resistor box for the obd 1 harness/ plug that they use? I don't know too much about electrical.

The OBD-1 resistor box that I was talking about was on the Hondas. I think it might have been Manny (presure2) who mentioned something about wiring in the resistor box from a 3sgte. I would read back through the posts and see who wrote that, and ask them if they have any insight on how to do that. I already have a 3sgte and the resistor box so MINE was a little bit more simple. You COULD just always get new injectors like the RX7 injectors that are a direct drop in with no modification needed to any wires, or fuel rail. Good Luck!