I have been combing through and reading everything I can, but for the life of me, can not get an AFR to read in the Tunerstudio.
The car was running great prior to installing the MS3pro pnp. The car now starts, and then rev hunts until it dies out. I looked at the datalogging and tunerstudio, and there is 0 reading for the AFR. The AEM gauge is reading AFR, but seems to be not sending the information to the MS3 or the MS3 doesn't know what to do with the signal.

Installed an AEM x series 30-0300 wide band eugo.
GREEN/BLACK wire to CANL
WHITE/BLACK wire to CANH
Power and ground wired to switched power (door buzzer and ground).

I have also wired in a 120ohm resister at the end of the CAN Bus (gauge side)
I have attached the current tune (built off the 90-93 basemap) as well as a couple of data logs.

The GM IAT sensor was installed half way through setting up the MS3.
Any insight would be GREATLY appreciated... Theres something I am missing, I just cant place it.

 

It looks like you have the MS set up like DIYautotune suggests.
According to google, the AEM gauge sends out data on CAN continously. You could throw a meter on the CAN bus (on AC volts) and see if you
have CAN bus activity. Also double check that the signal is getting back to the correct pins on the cpu.

Looking at your tune, shows some other issues which is why the engine does not continue to run.
1. Your MAT reading changes when you are cranking. Maybe a signal ground is not properly connected?
2. Your MAP signal should be going to 95-100 when you are not cranking. Right now it is only going to 85. Not sure what is causing that. Do you have the correct sensor configured?
3 It does not seem like you are giving the engine enough fuel to run. I see you have 265cc injectors, and the PW's are much lower than mine. What AFR is the wideband reporting?
4. You may wish to disable fuel enrichment based on MAP, until you have the engine running properly.

 

^ what he said

If MAP is not reading around a hundred when car is off, you have the wrong map sensor selected in the menu and it will never run. 85 isn't right

 

Well I ordered a Genuine GM IAT sensor. Ill get that swapped out, but I should have it set to the correct sensor. Maybe the one I ordered was defective or not the correct sensitivity.

I'll hit it with a voltmeter on AC to see if theres any activity going to the ECU. Not sure what voltage I am supposed to see on a CAN Bus.

I will likely just call my tuner (wasn't planning on going to him until the rest of the turbo bits were in) to see if he can spot anything...

 

Seeing any AC volts on the Can Bus indicates there is activity.

It is the MAP sensor that could be improperly configured, not the IAT sensor.
Yes, the IAT sensor reading is changing during cranking, but that would not be a sensor problem.

 

About 2 volts on CANL and 3 volts on CANH. Multimeter in DC volts, scale 20V.

 

Does everything look okay here in terms of the MAP sensor calibration?


I tested the CAN Bus going to the ECU:
CANL - 2.2V
CANH - 2.55V

I suppose this means there's signal/information going IN to the ECU from the gauge. The ECU just isn't reading, or receiving it correctly?

 

Looks like the correct sensor is in confirured, however I don't believe you have 2 independent sensors for Barometeric correction?

If you are not sure, try setting that to "initial Map reading" and then retest to see if your Map is close to 100 with the engine not running.

 

Changed a couple of the settings as discussed, but MAP is still reading 85 with ignition off. I suppose the MAP sensor could be bad?
The question is then.. do I replace the on board, or run an external MAP sensor?

The other questions remains unsolved as to why my ECU refuses to see the CAN signals from the AFR...
I really dont want to switch to analogue signal.. as it is inferior, but it might be what I need to do to get this running. Unless someone has some wisdom to lay on me

 

I presume you mean with the engine off. It seems unlikely that the map sensor is bad.
Please check one last thing. Measure the +5v on the megasquirt. Measure it with the engine off but ignition on, and then measure it while cranking.

 

You want me to install a pin to the +5v on the options port and check for voltage? (happy to test, just want to confirm I am testing the correct output.)

 

^yes, that is one way to do it.