02 modifier/ voltage clamp, need help!

[duMb KeoLa]

okay, so i installed my o2/ voltage clamp, but sometimes when i go wot my car goes max lean. i dont know if i hooked it up wrong or if thats just how its going to be, but i dont like red lights on my a/f meter at wot. anyone know if its possible to hook up the o2 modifier backwards? and if so, would that cause the car to go lean at wot? its fine if i go partial throttle at bo0st but wot is lean. thanks for the help

 

[NC_MP3]

The modifier works for partial throttle only, so if you are ok ar partial then your modifier is cool. WOT will cause the ECU to go open loop, so it ignores to O2 sensor anyway.

Try adjusting your FMU to put out more pressure and make sure you are only running low boost and not overboosting to like 10 or something.

 

[spoolinmp3]

Sounds like your gauge is still not working correctly. Did you double check the ground install?
Yes like Jim stated the 02 modifier will not affect a/f ratios at wot

 

[chdesign]

Yo Terry yo mailbox full I need to order that oil restrictor from you hit me up e-mail me ferrari246gtdino@aol.com and I can get this ordered from you.

 

[Kooldino]

duMb KeoLa - YOu didn't happen to take pics of the O2 voltage clamp install did you? I'll be doing it this week...

 

[perfworks]

WOT will cause the ECU to go open loop, so it ignores to O2 sensor anyway.

only above 4500 rpm's.
under that the ecu will stay in closed loop at prprogramed valus ignoring the o2 sensor input to the ecu.

 

[duMb KeoLa]

aw s***, so even with this o2 modifier the gas will still be cut until you hit 4500rpms at wot?? so i mean, if im cruising on the freeway, and i down it to 3rd, it will go lean until after i hit 4500rmps then it will go rich? cause thats pretty much what ive been experiencing...i thought the o2 modifier would get rid of that but i guess not, is there anything to get rid of that lag before 4500rpms?? thanks

 

[perfworks]

aw s***, so even with this o2 modifier the gas will still be cut until you hit 4500rpms at wot?? so i mean, if im cruising on the freeway, and i down it to 3rd, it will go lean until after i hit 4500rmps then it will go rich? cause thats pretty much what ive been experiencing...i thought the o2 modifier would get rid of that but i guess not, is there anything to get rid of that lag before 4500rpms?? thanks

the o2 clamp is there to make sure the ecu does not see a rich condition.it sends the ecu a 14.7:1 input.

it does not richen the mixture for you.
thats why you have a rising rate regulator..
you might be seeing lean or stoich reading but i believe it is just catching up. nothing to worry about .
thats why i said in order to verify this condition you need to have an A/F gauge (accurate one) and an EGT. all those will help diagnose along with a wide band o2

 

[NC_MP3]

OK, here is how it works, in theory.

Closed loop means the ECU looks at things like the front O2 sensor and constanly adjusts fuel to keep it at an optimal air/fuel ratio.

Open loop is when the ECU ignores those sensors and works on a preset fuel and timing map. I don't know for sure, but this happens at 4500+ as others have stated. Again, not sure if this is true or not. It may go open loop when a combination of things happen, like TP at a certain %, or MAF at a cerain lvl.

Anyway. During closed loop, the front O2 sensor can "see" the extra fuel being dumped in by the FMU. The ECU then reacts by cutting fuel. This can cause lean conditions at partial throttle.

The O2 modifier alters the voltage from the O2 sensor under boost, therefore the ECU never senses the extra fuel.

Then when it goes open loop, it goes to the preset map which is rich, so you should be fine.

I don't have my O2 mod hooked up right now, so I can see when this is happening. At partial throttle the A/F goes rich, then starts leaning out.

When the ECU goes open loop, the A/F immediately goes rich.

So, in theory, with the O2 mod hooked up you should always see a rich condition when boosting.

That help any?

 

[LinuxRacr]

only above 4500 rpm's.
under that the ecu will stay in closed loop at prprogramed valus ignoring the o2 sensor input to the ecu.

Everything is backwards in this post, except the fact that above 4500 rpm's. Like NC said, Open loop is when most sensors are ignored, and the ECU operates under predetermined values for WOT (above 4500 rpm). Closed loop (kinda like a closed ciruit) is where the sensors are "in the loop" of things.

 

[perfworks]

Everything is backwards in this post, except the fact that above 4500 rpm's. Like NC said, Open loop is when most sensors are ignored, and the ECU operates under predetermined values for WOT (above 4500 rpm). Closed loop (kinda like a closed ciruit) is where the sensors are "in the loop" of things.

linux this is not backwards.
the protege ecu works differently.
above 4500 rpms it will go into open loop either wide open throttle or partial.
now forget that for a minute.
under 4500 rpm's: closed loop no MATTER WHAT . WOT , PARTIAL ,doesnt matter.
but at WOT it works off a fuel map according to load and TPS < MAF voltage. the o2 is used only as a reference to make sure the system is working proprly. at partial throttle it will incorporate for the most part o2 voltage signal and modify to get a stoich reading. sounds backwards but it isnt.
the confusing thing is at WOT the meter will read stoich and at partial it will read coser to the rich side.
again this i found is only the case in the protege ecu.

 

[perfworks]

now in regards to open loop and closed loop.
even in closed loop the ecu has a base values it runs off of. the sensors input are only used as a reference to accomidate load and throttle position. it uses these signals to " variate" from its set perameters when it NEEDS to.

no matter how intelligent the computer it cant possibly correct every fuel and load condition .
it can only help improve it outside the norm.
thats why they use a reference on the regulator from manifold pressure to control the right amount of fuel every time the injectors cycle. the ecu only controls how long they are open based on preselected maps in both open and closed loop.

 

[Kooldino]

Here's all I know about open and closed loop...
http://www.flyinmiata.com/protege/tech/ecu_theory.asp

Although I have heard the 4500rpm thing before. FM guys, got any input here?

 

[Keith@FP]

Just got back from the track.

The computer switches from open loop to closed loop based on load. At WOT, that means it's at around 4500 rpm. At partial throttle, it's higher (if at all). There are other parameters as well, but those are the primary ones. There is no switch at 4500 that forces the ECU to go open loop. WOT is not usually used to discriminate, instead it's load that counts.

In closed loop, the computer modifies the stock map depending on what it sees from the O2 sensor. It's got a huge range of authority, able to pull 30% or add 25% of the initial fuel value. It will maintain a stoich ratio even if you've jacked the fuel pressure. This is based on readings with an ODB-II reader and an onboard wideband O2 sensor.

Older computers were simpler and would behave in the fashion perfworks describes. For example, the first generation Miata would go open loop at WOT or at 4000 rpm, whichever came first. The current Proteges are far more complex.

Keith

 

[duMb KeoLa]

okay, so say this, i step on the gas WOT to the max at only 2gs on the tach. what i see now is that the car goes to full lean until i hit about 4500rpms, then i feel a "bo0st" in power (which im guessing is more gas/more power). should i be experiencing this or you think i have a problem? sometimes i can play with the car, go wot and off the gas and itll go from lean to rich, lean to rich, and i noticed that it only happens at lower rpms. thanks

 

[Keith@FP]

I'd guess your voltage clamp isn't hooked up correctly - or if you did it yourself, it's not set to the correct voltage. Disconnect the vaccum line to the switch (make sure to plug off the line so you don't have a boost leak) and see if anything changes.

Keith

 

[perfworks]

Just got back from the track.

The computer switches from open loop to closed loop based on load. At WOT, that means it's at around 4500 rpm. At partial throttle, it's higher (if at all). There are other parameters as well, but those are the primary ones. There is no switch at 4500 that forces the ECU to go open loop. WOT is not usually used to discriminate, instead it's load that counts.

In closed loop, the computer modifies the stock map depending on what it sees from the O2 sensor. It's got a huge range of authority, able to pull 30% or add 25% of the initial fuel value. It will maintain a stoich ratio even if you've jacked the fuel pressure. This is based on readings with an ODB-II reader and an onboard wideband O2 sensor.

Older computers were simpler and would behave in the fashion perfworks describes. For example, the first generation Miata would go open loop at WOT or at 4000 rpm, whichever came first. The current Proteges are far more complex.

Keith

basically what i was saying in my proir posts.

now in regards to the last statement with the ecu going into open loop over 4000 rpm.
what i was trying to say is that "normally if you are going to rev to that level on this car you are depressed more than partial throttle and giving a value of load to the ecu .
i should have clarified that point sorry..

 

[Keith@FP]

I'm a road racer (no, that's not the same as a street racer). It's quite normal to be above 4000 rpm on partial throttle. Tuning for WOT only is easy. Tuning for partial throttle is where it gets difficult...

Keith

 

[duMb KeoLa]

okay, well if you think that i hooked it up wrong what does it mean by ecu side and harness end? thats the only thing i had a problem with but i think i connected it correctly. besides that, my previous statement wasnt meant the way it was taken i think and hope. i tried again and it goes to rich, once load comes THEN it makes its way back to stoich/lean, and i think once above 4500rpms it jets back to rich. anyone else experience this? hope so, laters

 

[perfworks]

okay, so say this, i step on the gas WOT to the max at only 2gs on the tach. what i see now is that the car goes to full lean until i hit about 4500rpms, then i feel a "bo0st" in power (which im guessing is more gas/more power). should i be experiencing this or you think i have a problem? sometimes i can play with the car, go wot and off the gas and itll go from lean to rich, lean to rich, and i noticed that it only happens at lower rpms. thanks

it is completely normal.
at 4550 rpm's the secondaries in your manifold open and bieng that your WOT you will feel a slight surge.

as i mentioned in a ton of threads at partial throttle you will notice it on the rich side under and over 4500rpm's.
at wide open throttle UNDER 4500 you will notice stoich which i believe on your gauge will cycle back and forth to show that measurement.
above 4500 WOT you SHOULD be stioch to rich. (open loop)

again for the billionth timeD ) you NEED a wideband O2 and FUEL PRESSURE gauge to verify the situation and be able to understand the operation of the system.
just raeding about it is not enough