AFR Problems

[loki2043]

So i have been watching my AFR's on my laptop with my maft pro and I have a few concerns.
1 being that when I let off the gas the AFR goes to 13.0 and slowly rises up i would say around 1 to 2 points a second.

2nd, When driving around if i decide to floor it the AFR goes to around 16 for a quick second then back down to 12.

What SHOULD I be seeing my AFR's do?

I am running maft pro w/ speed density. Nothing has been tuned yet.
I logged a few runs so if somebody is interested I can post them.

 

[super.secret.supra.club]

yes, please post the runs you've logged.

 

[dumbo]

you running PTT or still got the stock o2 sensor hooked up?

 

[loki2043]

I still have the stock 02 hooked up.
here are the logs, I dont think the titles are too accurate

rename the files to .csv

 

[strippedsup87]

Well from what I have learned through tuning my dads 05 hemi truck....the afr will pretty much bounce between 13 and 17 while driving around...and when going WOT an d than letting off it will go very lean for a few seconds...I think all this is quite normal though....

 

[grimreaper]

^ what do you tune with?

sounds normal, mine goes rich for a split second and then lean if i stay out of the gas. The split second of lean when you hit the gas sounds like the injector correction (term?) that jdub has mentioned. ill see what i can dig up...

 

[super.secret.supra.club]

looks pretty normal to me.

 

[loki2043]

Cool. I figured it was supposed to shoot lean on decel. not gradually make it there. it goes straight to lean when i lay off the pedal after going WOT. I haven't started tuning yet, been busy with work and all.

What about going lean when i floor it from a cruise? that's normal??

 

[thedave925]

Are you throwing any codes?
If you don't work with the ecu, it will default to 10.5 - 12.0 afrs and really crappy timing, very hard to work around under 3k rpm.
Look into the Throttle Response settings, with Enrich and Decay. That will help smooth out driving around town alot. I have mine set at 50 enrich and 30 decay, with throttle size at 1 due to how close i mounted my map sensor, with a tap between runner 3 and 4.

 

[loki2043]

I am throwing a couple codes, from having the maftpro. unplugged HAC and unplugged AFM.

she idles around 14.5 AFR

I will go run the codes here in a minute and report back.

 

[super.secret.supra.club]

its been 7 mintues!

 

[thedave925]

Plug in the HAC. I have a 90 and left mine plugged in, never did the mod to the ecu and everything is fine.
I fixed my afm ghetto-style= i got a resistor, you want one that reads about 1200 ohms, and i took the two ends and stuck them into the prongs on the afm plug. i'll have to look which wires exactly, but thats half of how i took care of it. I also had another resistor of 1200 ohm i put inline to one of the wires on the ecu harness, i'll have to check that wire too. Be back for that in a bit.

Edit: Resistor next to harness is in line of the light green wire for afm
Resistor stuck in harness plug spans from the brown wire next to the green wire and into the blue wire with red stripe.
These 2 resistors tells the ECU the air temperature and 1200 ohms is supposed to be the median, not too cold or too hot. I'm pretty sure it was Jetjock who wrote some info in an older post having to do with code 21 or 24 and the maft pro, not sure atm...

Thats good idle afr, what does your Vf say? should be high 2.xx low 3.xx volts

 

[loki2043]

codes 11 24 32 and 51

Im not sure on the VF, is it not in the log i posted?

 

[loki2043]

Why should i put a resistor in? wont it then give the TCCS a false reading and then my maftpro will try to fight that?

 

[thedave925]

The resistors are to help the ECU verify that the afm is plugged in, by changing the voltage not the ohms. Its for the air intake temperature, which for some reason in my setup the maft pro won't simulate accurately.
Edit, resistor values should be 2.2k ohm.

Codes via the TSRM:
there is no eleven, verify what your counting
24: Intake Air Temp Sensor Signal, part 1 of the why for my installing resistors
32: Air Flow Meter Signal, part 2 of the why for my installing resistors
51: This mostly happens when you open the throttle while in diag mode. It goes away if you don't open the throttle. Unless your TPS is misadjusted or something is missing in the A/C circuitry

I put in resistors to take care of my codes 24 and 32. It offers the ecu some form of unchanging stability. Also, another issue the resistor takes care of is that when you first key on your car, the ecu looks for the afm faster than the maft-pro can boot.
In my case, even booting up the maft-pro on the ACCessory power circuit before the ECU didn't resolve my code, hence the need for a resistor.

Once you take care of your codes the AFRs should hit lean asap when you let off the throttle and shouldn't dog down rich before climbing back to ~stoich when you tap the gas while idling.

Useful links:
Code 24 w/maft pro

Throwing Codes: 24, 32, and 41

Code 24 with my maft pro

Once you have your codes out of the way, read this then tune more:
MAFT-Pro VE Table

Hope that all helps, cuz seriously its hard to understand the maftpro when all the info is spread out this much. I wonder if/when someone will take the time to consolidate all the important stuff...
Happy reading

 

[loki2043]

Thanks for the clarification, i will read up on all of this later tonight.

as for code 51, my ac doesn't work (leaky hose) but all the circuitry should be fine. i don't think i had the throttle open, as i had just pulled the ecu fuse to reset the codes.

hmm, that leaves me with the tps. at close the tps voltage is 0.38ish and wot it is around 3.30ish(ill have to check and confirm wot voltage)

Ill try adjusting it tonight or tomorrow.

 

[grimreaper]

that sounds normal as well

 

[thedave925]

I'd leave the Throttle body and tps alone.
What happened probably is that you jumpered the Diag block, and while you were getting comfortable sitting in the driver seat you might have tapped the throttle, which brings up the code in numerical order. Then the CEL starts all over again, and if you don't hit the throttle you won't see code 51 this time.
If there really is a problem maybe its cuz someone attempted to raise the idle rpm using the throttle linkage stop on the body, its a small flathead set screw with an 8mm nut to help lock it into place. That would create an open IDL circuit, throwing code 51.

I don't think you need to worry about your code 51.

Those TPS voltages are right in the correct ballpark, and they should read pretty steady on the Maft Pro display.

Read those links before you fiddle more with your car. Better to go in armed with an ideal goal

 

[loki2043]

Sweet, thanks man.

i will check it out!

 

[loki2043]

The resistors are to help the ECU verify that the afm is plugged in, by changing the voltage not the ohms. Its for the air intake temperature, which for some reason in my setup the maft pro won't simulate accurately.
Edit, resistor values should be 2.2k ohm.

Codes via the TSRM:
there is no eleven, verify what your counting
24: Intake Air Temp Sensor Signal, part 1 of the why for my installing resistors
32: Air Flow Meter Signal, part 2 of the why for my installing resistors
51: This mostly happens when you open the throttle while in diag mode. It goes away if you don't open the throttle. Unless your TPS is misadjusted or something is missing in the A/C circuitry

I put in resistors to take care of my codes 24 and 32. It offers the ecu some form of unchanging stability. Also, another issue the resistor takes care of is that when you first key on your car, the ecu looks for the afm faster than the maft-pro can boot.
In my case, even booting up the maft-pro on the ACCessory power circuit before the ECU didn't resolve my code, hence the need for a resistor.

Once you take care of your codes the AFRs should hit lean asap when you let off the throttle and shouldn't dog down rich before climbing back to ~stoich when you tap the gas while idling.

Useful links:
Code 24 w/maft pro

Throwing Codes: 24, 32, and 41

Code 24 with my maft pro

Once you have your codes out of the way, read this then tune more:
MAFT-Pro VE Table

Hope that all helps, cuz seriously its hard to understand the maftpro when all the info is spread out this much. I wonder if/when someone will take the time to consolidate all the important stuff...
Happy reading

Okay, now after some reading on those links Jdub talks about the maft pro supplying the temp reading. im confused now. When the ECU sees that there is no temp reading it automatically resolves to 65? will the maft pro adjust that setting acording to what my AIT is really at?
Also, same goes for if i put a resistor in. some people are saying not to use a resistor and Dr jones says the code dont mean shit? then somebody says to wire it up to ACC so it gets the reading.

Somebody chime in here and put the truth? :aigo: