velella

hey guys, first let me say i would have searched more but my internet is getting shut off in about 20 mins for 2 days so i dont have time so for that i appoligize! i am still having alittle bit of tuning problems on my NA-T 1999.

set up:
stock compression and fuel
xspower kit
5psi
aem FIC
aem wideband.

thats the main stuff. what i need to know is how to throw my car in open loop mode and keep it there. I dont care about check engine lights or anything, but my tune keeps changing depending if the car is warmed up or not, I live in florida so i dont have any real cold starts to deal with. so i just want to keep it in open loop mode so it cant change my tune, and i can tune it once and for all. Thanks for your help -Velella

kene

iTrader: (2)

You do this at your own risk, I am not responsible for any damage you may cause on this vehicle.

This is a methoid that has worked on other vehicles along the lines of civics, tercels,etc


find out which sensor(thinking coolant/engine temp sensor) is giving the signal to the ECU to determine whether it should be in open loop or not.
1) find out what supply voltage the sensor runs off of(I simply do this as a reference). measure the voltage off of the power leads to the sensor(the positive and negative wires on the plug).

2) find out what the resistance is of the sensor as it is in open loop mode. ( when the car is in open loop mode temperature, turn it off and disconnect the cable plug from the sensor and measure the resistance of the sensor at the two power lead prongs on it.) write this down.

3)Now we need to find out what "wattage"(amount of power) resistor we will need.

Take the voltage measured (V) and the resistance measured(R) to obtain the
current(I) running through that sensor.

use this equation to get "I"(Ohm's Law):
V/R = I

I = _____(put your value of current here)

4) Now we will use the power equation of:


P = V x I

P = ________(the power[watt] limits of the resistor)



So you will need to buy a resistor of your calculated value "R", and minimum power(measured in watt) rating of what you calculated and place this resistor across the 2 power(positive and negative wires) wire leads in the sensor plug.

Rising_Sun

iTrader: (2)

Well you should really buy an OBD2 Scanner. Cold start is Open loop and WOT is Open loop. Closed loop operation happens when the motor reaches operation temp (180 degrees). Then it will adjust fuel trims from data received from the o2s.

velella

I am on my iphone so i cant type to much. is that the only way to keep your car in open loop? i have had so many problems with the FIC and have tried all different o2 setups. i just want to keep my car driveable. the car adjusts everything and runs like crap, until i floor it than it runs great. in boost is the only way to drive it right now, other than that it bogs around and keeps changing the tune. i just want the easiest way to keep it at one tune.

GS4_Fiend

iTrader: (22)

Just disconnect the darn ECT LOL.

JeffTsai

iTrader: (1)

You're not tuning the car right if you can't get it to drive normally in closed loop. I've done several GS and IS on FIC's as well as many other cars. They all drive around perfectly fine. You need an OBD2 scanner so you can tune in line with the fuel trims the stock ecu wants to see.

In the FIC you set the MAF voltage to offset the piping diameter change. Stock MAF pipe diamter is around 2.25", so if you put in a 3" MAF housing then you will have to increase the voltage across the MAF map to compensate for that. You also need to set a MAF voltage clamp of around 3.6-4V. You need to play around with the exact number to find the point where the car doesn't limp out.

Normally you would need to tune the whole injector map to offset bigger injectors, but since you're on stock injectors you only need to bump fuel up in the regions of boost. After that, you need to make sure the o2 trims aren't too out of whack. Tolerable long term fuel trim range should be targeted around +/- 5%. If it's too far out, then you will need to tune the O2 offset compensation map. Dial it in until you get the long term trims in check.

Finally, you will want to use the OBD2 scanner to see what kind of ignition advance you're getting under full boost. I would suggest you keep it around 15-18deg or so under full boost to keep it on the safe side. The stock ignition timing is quite a bit more aggressive since this car wasn't boosted from the factory. You will need to go into the igntion retard map and pull back timing in full boost regions to keep the engine safe.

These are just some basic tuning guidelines, but it all takes a bit of tuning experience to really dial a car in. You really need a OBD2 scanner so you can see some basic things that are going on under the hood. Make sure you also have a wideband in the car as well so you can tune to the proper AFR to prevent melting the pistons.

Tuning a car like yours with minimal power increase over stock and on stock fuel should be very easy to do. It's a good starting point for a beginner. Even tuning novices should be able to dial it in acceptably if they have a good basic understanding of engine tuning concepts.

BUT...back to your original question. If you REALLY want to force the car to run in open loop. On this car specifically there are a few ways. The first way is to unplug all four of the O2 sensors from the ECU. This will automatically throw the car into permanent open loop condition. Also, remember to remove the O2 sensors out of your exhaust after you unplug them and replace it with a O2 sensor plug. If you don't then you will kill the O2 sensors very quickly. The sensors have a heating element to help burn off carbon deposits from the sensor. If the heater is not plugged in and the O2 is still in the exhaust, you will coat the sensor with carbon and kill it in very short order. The other way to force open loop is to unplug the coolant temp sensor. The downside to that is the car will idle at around 2000rpm all the time no matter what.

Obviously those two are not the correct way to tune a car, but if you really want to force open loop...then there you go.

Best of luck in your tuning adventures

PS: When you force the car into permanent open loop condition, obviously you will have to be constantly retuning the car. You might even need to have a morning/night and afternoon map. Temperature swings are enough to throw off your tune if you are in open loop all the time. The closed loop is there to keep the tune in check when temperature, humidity, altitude, amospheric pressure, and other environmental factors change.

tommyGS3

iTrader: (4)

jeff,,,, if only u live in so-cal..... we would love to live next door to your.. the guy next door....lol

velella

ok i mean it drives, but you can tell a huge difference in the open loop and closed loops. i unplugged all the o2 sensors because it was skrewing everything up even more, and now its still adjusting the tune. i dont get it. im great at the mechanicle stuff but once we start dealing with wiring and **** i skrew everything up, i even called titan because there right down the street from me, and they said they havent delt with this and it would cost me 5-800 bucks to rewire all of it, fix the o2's and tune. im poor enough that im having to sell the car and cant pay that.

GS4_Fiend

iTrader: (22)

You have to install the 02 sensors properly or else you will get sluggish driveability.

JeffTsai

iTrader: (1)

If you were around me, I could knock that tune out in about 2-3 hours on a dyno. Either that or I can get a rough tune on the street to make the car driveable within a day. Not too many people know how to tune these cars. The process and method is different than most other cars because the ECU in this car is highly adaptive and will do whatever at all possible to keep the car running as close to the factory tune as possible. The thing is that you have to first trick the ECU into think that everything is running normally. If you don't nail that down, then anything else you try to do will fail.

Also, this maybe small and stupud but it may be something that you overlooked. Where is your MAF sensor located(suction setup, blow thru setup?)? Are you 100% absolutely sure that the MAF is sealed correctly against the flange with zero leaks? The reason I'm asking is because it should be VERY easy to tune a car on stock fuel system. If you're having such severe problems then maybe something else is at fault.

GhostDog88

Do you know if anyone has done this and what Resistor they ended up using to stay in OPEN LOOP mode?

Rock-a-Lex

iTrader: (4)

Jeff Tsai is spot on.

for the record I have the FIC8 on my SC'd GS400 and it runs awesome. Passed NYS inspection for 2 yrs in a row so far and tune never changes. I just need to tune for power but first perhaps change my injectors to a different set and maybe change up my fuel pump.

Anyway, you do not need to try to trick your car in open loop. First, do the basic setup for injector size change and IC pipe size change. Then, adjust your baseline fuel map that was just created by driving your car in closed loop (fully warmed up and normal, no boost driving) while connected to a live data scan tool.

Monitor your short term and long term fuel trims at ALL RPM intervals. If you see -18% while cruising at a certain RPM for example that means that the stock ECU is detecting too much fuel from the FIC fuel map, and is manually reducing fuel by 18%. You would then make that rpm, apsi cell a smaller value if positive, or, if all your values are already negative (if you have larger injectors) you would have to make the value an even larger negative, removing fuel. All this in an effort to bring that -18% down to say -2%, 0 or +3%.

As Jeff mentioned anything from -5% to +5% range is good and keeps the stock ECU happy! Once the stock ECU is happy in closed loop your car will NEVER override your tune. All this is WITH the upstream O2 sensors in tact. As soon as you go WOT (approaching, and in boost) the stock ECU reverts FULLY to the FIC tune.

That's basically it. No need to use the O2 map adjustment and you're not really running enough boost to need to worry about your ignition timing map. Also, make sure you have one step colder spark plugs. Good luck

badblackgs

iTrader: (1)

you need to retract that last sentence. the 02 skew map is EXTREMELY important. your adding boost while your factory computer is in closed loop and at the same time increasing fuel so your mixture goes richer, than your o2's will detect that excess fuel that is not what the factory ecu wants to see. the skew function is to trick the o2's so that when your making a richer mixture while its still in closed loop, the factory ecu doesn't try to trim it out.. others read this stuff when they take on their builds and misinformation can cause alot of headaches. since your cars running awesome, lets see some videos.

Rock-a-Lex

iTrader: (4)

Not going to retract anything! And it's not misinformation. You are DEAD wrong! Read the FIC8 instructions, you do NOT, I repeat do NOT need to run your O2 signal wires through the FIC. You do NOT need to use the FIC o2 skew function.

and I spoke to AEM techs directly and they said the same thing. And that's all those people deal with day in and day out, tuning and tech support.

and I recall speaking to JeffTsai that said you don't have to mess with O2 skew/maps to tune with the FIC. And he's tuned tons of GS's.

car runs awesome, but as you know, don't play dumb now because we've spoke on the phone a bunch of times , my tranny doesn't shift like yours because I don't have a valve body upgrade yet. Stupid to put a video up where I have to let off the gas between shifts to allow it to shift. The car is a beast. i need to get my car tuned for power but first I need to put my new wideband in, which we also discussed. So I can't tune for max power yet or smooth my maps without a good reading WB. I suspect my 3yr old WB is shot from running stupid rich in the very beginning when my FIC wiring was jacked up from Boomslang. I'll put up videos soon when I can portray it in the best light.

No check engine lights either...like I believe you're getting rich codes.