installed wideband & AFPR, idle is very LEAN!!!

[mk3tattoos]

my friend and i just did the install on a SX AFPR, innovate wideband, test pipe, and 12v mod. When we get all the work done and stared it up the wideband shows its running very lean (16.2-16.5). We set the AFPR at 40psi with vac line off, so we then set it higher to try and richen it up. No luck, so we then adjusted the afm screw, we screwed it all the way in. no luck there either, so then my friend unplugged the o2 sensor and it went to (12.8-13.1). So any thoughts on this would be great. why does it run fine without the O2 sensor, and is it Ok to run the car with out it? I put a brief mod list to let you know whats been done. and pics of the AFPR. thank you very much guys.

fresh jdm 7mgte
ct26-57 trim
blitz nur spec exhaust
titan divorsed down pipe
test pipe
apexi intake
walbro 255
rc550
lex afm
turbo xs blow off valve
greddy timing belt
titan mhg
arp bolts
perrin mbc (15psi)







we will move the wideband later, just temporary.

 

[thevork]

A/F Around 16 @ idle is not really a big problem.
Are the A/F values normal when driving? An A/f of about 13 @ idle would concern me more than the values you get with the O2 on.

My first guess would be a small vacuum leak. Is your BOV closed completely?

 

[mk3tattoos]

A/F Around 16 @ idle is not really a big problem.
Are the A/F values normal when driving? An A/f of about 13 @ idle would concern me more than the values you get with the O2 on.

My first guess would be a small vacuum leak. Is your BOV closed completely?

i can feel the blow off sucking air sometimes, its going through the vacume line though. when I'm cruising it is at 13, wot its @ 10. So what are the Ideal numbers? I was under the impresssion 16-17 @ idle was way to high.

 

[Mark2]

i can feel the blow off sucking air sometimes, its going through the vacume line though. when I'm cruising it is at 13, wot its @ 10. So what are the Ideal numbers? I was under the impresssion 16-17 @ idle was way to high.

I imagine that idle should be around 14.5....16-17 is on the high side.

 

[dumbo]

how are you controlling your fuel? i would be more concernced with the 10.0:1 at wot, thats a little low., loosing power and wasting cents on fuel.

 

[Angry7M]

Usually when people go with 550cc injectors and the LEX AFM, they have some kind of tunning device like a SAFC.

 

[dumbo]

Usually when people go with 550cc injectors and the LEX AFM, they have some kind of tunning device like a SAFC.

yah or a maft..thats why I was asking, didn't see any piggy back control.

 

[mk3tattoos]

Right now I dont have the money to just get everything at once. I'm not concerned with running perfect, just safe for right now. Sothern cali. is hurting for money, and economy is way down. So i will get a tunning device in a few weeks to control the fuel. But in the mean time were should the a/f be @ idle, @ cruise, and @ wot? Because i can take fuel away with the AFPR to help out with it being to rich.

thanks guys.

 

[grimreaper]

im betting that 10:1 af ratio is actually lower then that with that much fuel.

sounds like there is some pirate air getting in.
is the o2 sensor calibrated? any exhaust leaks?

 

[cjsupra90]

First thing I would do is take the WB sensor out of the exhaust and redo the heater cal and free air cal.... Then see what your getting... The other thing is did you mess with any of the out put programing of the LC-1 (assuming that is what you have)?
I would go into it with LM Programmer and first and formost make sure that it is set to gasoline 14.7:1 for the calibration and not some other fuel... I am assuming that your using one of the outputs (presumably #2) to feed simulated NB signal to the factory ECU, if so then make sure that that output is calibrated for standard 0-1v narrow band output and not something slightly off or what not...

The last problem is possibly the common ground offset problem thus causing the LC to output the incorrect voltage.. On Narrow band output, this can cause the AFR to be off by quite a bit cause of the low 0-1v output where as this has less effect on 0-5v wideband outputs.. Heres an example of this... My car which as a standalone EMS that excepts both 0-1v NB and 0-5v WB inputs.. With it hooked up and reading the WB output, the ECU in closed loop shows 14.7 sustained but logworks show 14.5 sustained so there is a very slight ground offset. Now if I change the output to simulated NB, the ECU still in closed loop tries still shows a sustained 14.7 but logworks now shows 15.4 but nothing has changed except the output and input type.. So you can see how a ground offset is exagerated on lower voltage outputs...

Im still thinking that there is a malfunction in the sensor or something with the calibration because the things you did (fuel pressure change and bypass screw adj.) should have shown some sort of change in the AFR readings but your saying that it didn't, or did it, but just not as much as you were hoping for or expecting to see????

 

[thevork]

Usually when people go with 550cc injectors and the LEX AFM, they have some kind of tunning device like a SAFC.

mind you that you can only use the fuel computer to tune the ecu in open loop mode. at idle the car is in closed loop.
closed loop means that the ecu is using the readings off of the lambda sensor to get the mixture to a perfect 14.7

@ idle 16.5 won't hurt the car a bit. You could experience a rough idle and sometimes even stalling but as long as that's not really your major issue i'd concentrate on things as vacuum leaks at the bov as you were saying.

a lean condition ( > 14.7) is most commonly caused by a vacuum leak as more air enters the engine than is measured. therefore the ecu does not inject the correct amount of fuel hence the lean condition.

 

[mk3tattoos]

First thing I would do is take the WB sensor out of the exhaust and redo the heater cal and free air cal.... Then see what your getting... The other thing is did you mess with any of the out put programing of the LC-1 (assuming that is what you have)?
I would go into it with LM Programmer and first and formost make sure that it is set to gasoline 14.7:1 for the calibration and not some other fuel... I am assuming that your using one of the outputs (presumably #2) to feed simulated NB signal to the factory ECU, if so then make sure that that output is calibrated for standard 0-1v narrow band output and not something slightly off or what not...

The last problem is possibly the common ground offset problem thus causing the LC to output the incorrect voltage.. On Narrow band output, this can cause the AFR to be off by quite a bit cause of the low 0-1v output where as this has less effect on 0-5v wideband outputs.. Heres an example of this... My car which as a standalone EMS that excepts both 0-1v NB and 0-5v WB inputs.. With it hooked up and reading the WB output, the ECU in closed loop shows 14.7 sustained but logworks show 14.5 sustained so there is a very slight ground offset. Now if I change the output to simulated NB, the ECU still in closed loop tries still shows a sustained 14.7 but logworks now shows 15.4 but nothing has changed except the output and input type.. So you can see how a ground offset is exagerated on lower voltage outputs...

Im still thinking that there is a malfunction in the sensor or something with the calibration because the things you did (fuel pressure change and bypass screw adj.) should have shown some sort of change in the AFR readings but your saying that it didn't, or did it, but just not as much as you were hoping for or expecting to see????

my friend hooked up everything perfect. its the car thats off. the car does not idle good @ 14.5 but does @ 13. so thats why we left it there. the AFR did change when we messed with the FPR, and screw adj. So is there any repercutions on running the car without the O2 senser or doese that just change the close loop

 

[mk3tattoos]

mind you that you can only use the fuel computer to tune the ecu in open loop mode. at idle the car is in closed loop.
closed loop means that the ecu is using the readings off of the lambda sensor to get the mixture to a perfect 14.7

@ idle 16.5 won't hurt the car a bit. You could experience a rough idle and sometimes even stalling but as long as that's not really your major issue i'd concentrate on things as vacuum leaks at the bov as you were saying.

a lean condition ( > 14.7) is most commonly caused by a vacuum leak as more air enters the engine than is measured. therefore the ecu does not inject the correct amount of fuel hence the lean condition.

oh ok thanks Vork!

 

[gofastgeorge]

I have never in my life seen a well tuned engine idle with the A/F in the 14.5 range.
Put an A/F meter on a brand new car, and the A/F will be 16 or leaner.
You are not trying to make power at idle.

 

[dumbo]

I have never in my life seen a well tuned engine idle with the A/F in the 14.5 range.
Put an A/F meter on a brand new car, and the A/F will be 16 or leaner.
You are not trying to make power at idle.

i'm not agreeing or disagreeing with the non bolded statements.

but i wouldn't worry about your idle afr as long as its on the lean side and eng is running smooth. just saving you gas, and prolly putting your NOX up.

i dont know how these car will run without the stock o2, i'm assuming not good, and prolly rich. i'm pretty sure you dont get much tuning abilty with the fpr, i would consider a maft or maft pro w/spd density and do away with the afm all together

 

[Patch]

A few years ago I installed a narrowband on my miata and didn't ground it right. Ran riiiiiiich. Had no power until 4000 rpms then it took off.

So yea, maybe its a ground issue you're having?

 

[tbcmorris]

mind you that you can only use the fuel computer to tune the ecu in open loop mode. at idle the car is in closed loop.
closed loop means that the ecu is using the readings off of the lambda sensor to get the mixture to a perfect 14.7

@ idle 16.5 won't hurt the car a bit. You could experience a rough idle and sometimes even stalling but as long as that's not really your major issue i'd concentrate on things as vacuum leaks at the bov as you were saying.

a lean condition ( > 14.7) is most commonly caused by a vacuum leak as more air enters the engine than is measured. therefore the ecu does not inject the correct amount of fuel hence the lean condition.

do you have anything to back this up? i was taught that idle is not one of the parameters that needs to be met in order to operate in closed loop. i was taught that it was more dependent on engine temp than anything. leading me to believe that there would be 2 different idle programs. one to satisfy cold startup idle(closed) and warm idle (open)my car idles at about 14.7 open or closed loop. my problems comes in on my WOT AFR where i dip below 10

 

[dumbo]

do you have anything to back this up? i was taught that idle is not one of the parameters that needs to be met in order to operate in closed loop. i was taught that it was more dependent on engine temp than anything. leading me to believe that there would be 2 different idle programs. one to satisfy cold startup idle(closed) and warm idle (open)my car idles at about 14.7 open or closed loop. my problems comes in on my WOT AFR where i dip below 10

i'm pretty certain cold start up is open loop, warm idle and everything under approx. 75% throttle is closed loop, and 75% to WOT is open loop.

or unplug the stock o2 and it goes to open loop, but rather pointless if you have no way to tune it.

 

[mk3tattoos]

when i leave the o2 sensor plugged in i run lean on the freeway @ 70 mph. The manifold will get red hot and the back of the turbo will as well. that seems pretty dangerous to me, now when i cruise on the free way at the same speed my A/F are @ 13.5. Is that way to low as well?

I do want to get a piggy back or an AEM-EMS unit later on down the road. But for now i just want to drive to work safely. So what are the right A/f readings for the freeway? please someone help with that.

and should i leave the o2 sensor plugged in?

thanks sooooo much guys

 

[mk3tattoos]

plugged the o3 sensor back in and it ran good. The A/F was (14.5) @ idle, cruising was the same. Now on wot it showed it to be around (11.7- 12). Is it running good enough to not hurt the car? Just until i can tune it later on. I figure i will make a video to show what its doing right or wrong.

Another question i had was about the AFPR, when i set it to 40psi with the vac line off, it changes psi to 35psi when i put the vac. line on. Is that normal?