So via a friend of a friend I'm picking up a Apexi SAFC tomorrow at a price I just can't say no to. i know I could put this thing on Ebay and sell it at a profit more then likely at the price I'm getting it for but I'm really thinking about installing it in my 91 SR5 and just putzing around. Hell maybe I can lean the thing out a bit (little by little until I run into my buddy and see if I can borrow is wideband) and get some more MPG out of the beast.
Thank you very much for taking the time to read my thread - however I think you missed the part about what my goals are.
I did not purchase it with the intent of getting more power. I'm curious to see if I can lean it down a little because I'm sure its got to be running rich. The goal here is MPG - not HP. Obviously a little power will come with it - but again, I really dont care about that at this point.
Anyone have some input with that thought in mind? If it doesn't work out - I'll just sell the thing. Pretty sure for what I paid for it I can make a few bucks or at the very least break even. So I pretty much saw this as a no lose situation.
You'd actually lose power going lean and the stock ECU doesnt really run that rich. On the down side you can risk engine damage if you lean it as the ecu wouldnt correct when you have low RPM and high load, which is what most people think is economical driving...
I'm not looking at blindly leaning it out until I get 70 mpg. I have a buddy that has a wideband to help play with this thing safely. I know he would let me use it to help tune the thing in.
I guess this is one of those... I guess we will see scenarios. And again - I know I can sell it for minimum what i paid for it... if not more. So I'm not to worried. If anything it will be an interesting learning experience. My buddy played with one on his Honda and managed to pull some more MPG out of it... I'd have to imagine there is something to be had on this motor too.
One of my concerns is actually what you bring up. What happens when you have a tune in and at a given RPM you have it leaned out X% and now you open up the throttle bring up the load on the motor and bringing more air.... how do you combat what is going to be now a leaner and learner condition.... playing with the high/low throttle points... or changing ones driving style?
You'd actually lose power going lean and the stock ECU doesnt really run that rich. On the down side you can risk engine damage if you lean it as the ecu wouldnt correct when you have low RPM and high load, which is what most people think is economical driving...
maybe the 6th gen is vastly different, but at WOT from 4000 on up i would see AFR's dip to 10.8 and 10.5, 10.2, 10.0 was as rich as I could read and they would go below that. below 4k at WOT I would see 11's.
how do you combat what is going to be now a leaner and learner condition
I'd adjust the cells in the fuel map on my controller.
Quote:
maybe the 6th gen is vastly different, but at WOT from 4000 on up i would see AFR's dip to 10.8 and 10.5, 10.2, 10.0 was as rich as I could read and they would go below that. below 4k at WOT I would see 11's.
Thats not SO bad...I get 9 on Wot myself, but thats because I'm running a safe rich setup... yeah I know sucks to be the piston rings in my engine..
Anyone have a link to a 4afe ECU pin out? I've been googling like crazy and can't find one. I found one on a canada forum but can't make sense of what he used for abbreviations. The stuff they give in the Apexi diagrams is definitely not what is in my car!
I ran to the auto parts store but they dont have a schematic that is of any use. The one book did have one but didn't list all the pins and then went by a color code that made little to know sense. Not to mention for say the TPS - which is what I need and I can move forward with the install... it shows three different pins for the TPS. Not sure which to use... would it be the one wired through the transistor in the TPS? I'm fairly certain that would be it... I just dont want to guess! lol
bottom of the 26p ecu from left to right as you are looking at the ecu.
14- E02
15- #20
16- E1
17- not used
18- E21
19- NE
20- THG
21- IDL
22- VCC
23- PSW
24- E2
25- OD
26- V-ISC
the 16 pin side from top left top right then bottom left to right. again top left to right is 1-8 and bottom left to right is 9-16.
1- T
2- ACT
3- STJ
4- ELS
5- FC
6- not used
7- BATT
8- +B1
bottom of the 16p left to right as you are looking at the ecu pinouts.
9- VF
10- not used
11- not used
12- SPD
13- A/C
14- not used
15- W
16- +B
btw this is for the 1990 4afe ecu. if you cant find what the pin out of the ecu is you can open it up and it is listed right by where the pins are soldered onto the board.
the 3 wires for the tps are PSW, IDL and E21
PSW = LG = lightgreen = not sure what this one is
IDL = L = blue = idle signal
E21 = BR = brown = ground wire
__________________
"driving safe doesn't mean driving slow"
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96'paseo 40mpg DD!!!!!
90' corolla gts smallport engine FS... "levin front conversion" "current project" - BEAMS 3sge in the works
Last edited by rdyzz; 07-17-2010 at 11:18 PM.
The Following User Says Thank You to rdyzz For This Useful Post:
That is pretty much what I found in the haynes manual but now you have at least explained what the three wires are for. Now the questions comes - which one do I take the signal from? Obviously dont want just an idle signal so i would assume the PSW one?
Or on second thought would I be taking the signal from the Idle circuit? I'm assuming this motor wouldn't care about the position of the throttle past a certain percentage and would just assume its WOT after that.
Which makes me wonder if I should be using the MAP sensor instead of the TPS. I would have to imagine that would help with the low rpm - high load tuning as well.
Its too late to think about this stuff..... time for bed!!!
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Apexi SAFC - Stupid purchase?
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