93 mr2 3sgte Idles fine but AEM wideband shows lean all the time

[FASTMR2]

finally it will idle and rev without it sounding like it gonna fall apart, I have a AEM wideband int the car and it is wired to my link g4x but I don't know if its calibrated correct. its a 31-4110 wideband that uses just a 5 volt out put. the dash gauge is showing lean all the time. file attached 

PC Datalog - 2023-08-1 8_11_57 pm.llgx

[Vaughan]

Have you wired the gauge up to the ECU? If so which input did you wire it up to? Also note that any exhaust leak upstream of the sensor will result in a lean reading

[DerekAE86]

That wideband controller is notoriously terrible. However the readout on the physical gauge itself should be accurate unless air is being injected into the exhaust from a leak or vacuum scavenger setup.

But if you're confident that's not the case and that the sensor itself is fine then the mixture will infact be lean.

If you bought the setup 2ndhand the previous owner might have been using a different calibration preset. There's a tiny rotary selector switch on the back of the unit accessible via a small hole. Check the manual for the setting options but I believe P0 is the default.

[FASTMR2]

I bought the wide band new it always worked fine. My stock ecu blew a capacitor which is why I installed a links ecu, 

[Adamw]

There is not even an analog input assigned to Lambda 1 in your log, so that would explain the ecu not reading correctly.  The MAP sensor isnt working so that probably explains the lean.  

[FASTMR2]

I looked at the data and it shows the map sensor is reading, when you say the map sensor is not working what do you mean. 

[koracing]

Your map sensor is going between minimum voltage and only slightly above minimum voltage when you open the throttle - it should change a lot more than it is.  It might indicate a restriction in the line between the sensor and the plenum of the intake manifold.  Try going to a different port on the intake manifold possibly.  Which map sensor are you running?  Was it the Omni 4 bar?  If it's calibrated properly you should see the MAP reading match the BAP reading when the key is on with the engine not running - is this the case? 

Your narrow band o2 is staying low voltage all the time indicating you're running lean according to it as well.  What manifold and downpipe are you running?

[FASTMR2]

It’s a Omni 4 bar it shows the same reading as the Bap at kOEO. I was able to get it to calibrate I will try and change the location of the vacuum line. Also I figured out the wide band is not set up correct. 

 

[FASTMR2]

ok i changed the position of the vacuum line and figured out that the wide band was wired into the wrong location, still runs lean. file attached 

PC Datalog - 2023-08-5 5_13_10 pm.llgx

[DerekAE86]

There's still something very wrong with your Lambda setup. Either wiring or configuration, but probably both.
That log is showing An Volt1 as assigned to Lambda1 at a constant 4.31v. It is near impossible for a running engine to have such a steady reading.

Not only that the Lambda1 runtime is reporting 0.086 Lambda. This means your calibration in your tune is very wrong because the AEM manual shows that a voltage of 4.3v would be around 1.270 Lambda.

Your MAP sensor is still wrong too. It's showing a solid 21.5kPa at idle. There's no way a running engine is that steady.

Attach a copy of your tune.

[FASTMR2]

I think this is the latest setup 

1.pclx

[DerekAE86]

Yes, both the Lambda and MAP cal tables were wrong. Your PCLink is probably using "AFR" as the units, but you entered the Lambda values into the Linear Cal. So it was showing 0.68 AFR (0.046 Lambda) to 1.37 AFR (0.093 Lambda), rather than 0.683 Lambda (10 AFR) to 1.365 Lambda (20 AFR)

I've fixed them in the attached file, however you'll still have to do the MAP sensor calibration process after you load the file.

1 (Fixed Cals).pclx

[FASTMR2]

downloaded the fixed cals file, by the way I do appreciate the help

PC Datalog - 2023-08-5 8_34_51 pm.llgx

[DerekAE86]

Really need more of a log than that to tell. Like Engine of -> idling -> and a small rev.

[FASTMR2]

ok try this one

PC Datalog - 2023-08-5 8_48_57 pm.llgx

[DerekAE86]

Your MAP sensor is not sending the voltages expected of the 4Bar Omni sensor.

Do you by chance still have the factory MAP sensor connected as well?
The factory sensor might be wired in and being monitored instead.

And the Lambda is not changing at all. Are you sure it's been wired into the ECU right?
Which wire from the guage have you connected to which pin on the ECU?

[FASTMR2]

the 4 bar map sensor is plugged into a factory connector, ATS racing sold me the map sensor. I have talked to them about it. I  have the white wire ran to the ECU using An volt 1 pin 33 connector C6 from the wide band. I have checked the connector for the map sensor it has a ground, 5 volt ref, and the voltage coming out of the last wire is what the ecu is reading. 

[DerekAE86]

Is your AEM gauge also just showing an unchanging 18.6 ish AFR?

If so it sounds like a dead sensor or failed wideband controller.

As for the MAP sensor they either didn't sell you what you thought or it's also failed. It seems to be reporting something but it's not right. Could still maybe be a wiring issue. grasping at straws but 5v and sensor and pins the right way around?

[FASTMR2]

yes the aem gauge shows beyond what the sensor will read, i will double check all the wiring tomorrow to see if maybe its not pinned correct. 

[DerekAE86]

Just to be 100% sure. What model Link ECU do you have, what was the PN of the original MR2 ECU, and if you get a multi-meter - check the MAP sensor signal pin back to the ECU; which pin on the ECU is it connected to?

[FASTMR2]

link G4X 222-4000  TST205X, I had a Access ecu part number PC23710T    it says 93+ mr-2 on the case, a capacitor melted and messed the board up the reason for me buying the link ecu. I will check the pin location for the map sensor tomorrow 

[DerekAE86]

Does it still have the Toyota PN on the other side?

@koracing will probably know for sure. But I suspect this "PC23710T" Blitz ECU is actually based on the early Gen2 MR2 SW20.

Good chance your MAP sensor isn't connected to the correct pin the MR2Link v3 is expecting.
Does your car have an AFM as well as the MAP sensor? Because "something" appears to be connected to An Volt4, but it's certainly not a (functional) 4Bar Omni sensor.

[FASTMR2]

it had a AFM but as per ATS Racings instructions you cut two wires off that harness to run the plug for the IAT temp sensor. Which I got FROM ATS, the IAT goes where the cold start injector used to be. the original setup did not have a MAP sensor, it a sensor where the new Omni 4 bar plugs into, but it wasn't a MAP sensor 

[DerekAE86]

If all the wiring is correct and the sensor is infact what it's supposed to be then just have to come back to this:

On 8/3/2023 at 6:12 AM, koracing said:

It might indicate a restriction in the line between the sensor and the plenum of the intake manifold.

[koracing]

You should have a "turbo pressure sensor" map sensor on the 93 Gen2 on AN volt 4 OEM.  The original vacuum line runs to a tee that also runs to the vacuum cannister on the throttle body - I would disconnect that and just run a hose without any inline filter/check valve between the map sensor and the port on the manifold without any tee or sharing any connection. You can also try plugging the OEM sensor back in and changing the map calibration to ST185 and see if it reads correctly.

Does your car by chance have any kind of fuel cut defender installed?