Installing a MSPNP2 on a 93 MX5 (before turbo install) and have car running but can't get a good signal from the AEM wideband to TunerStudio.
O2 signal on TS is erratic, varies from unresponsive, to number that matches local gage to off scale lean.

We have:
Checked O2 wireing from AEM controller to ecu
Replaced O2 sensor
Installed second new AEM controller/gage with new sensor.

Results were the same for all setups.

Ideas? Will get an msq file on here as soon as I can figure out how to do so

 

Which color wire from the AEM are you hooking up to the MS2? I think it is either the blue or white wire that needs to goto the MS. I can check tonight when I get home for sure.

 

We're using the white wire (0-5v). The current AEM Uego is the newer 4.9 sensor version. Don't think that really matters though. It's run to the 2n wire of the ECU harness (shielded R/L wire). Tested for good continuity through wire all the way through the plug at the ECU.

EDIT: Gauge controller is set to position 00.

The ground for the AEM is the same grounding point as the ECU, but it's not wired into the same actual wire. Individual wire.

It's a good switched 12v source with 10amp fuse.

When we monitor the signal wire with our volt meter it spikes high voltage numbers pretty rhythmically. 1.4 volts, spike to 18v or so, back to 1.4, spike to 18v.

The Tuner Studio display shows very little response typically. It sits at around 12, and occasionally spikes over to full lean if we're playing with the throttle.

The gauge itself (and the previous gauge) seem to display AFRs correctly. We though perhaps it was a lazy 02 sensor, and then perhaps a bad controller. Now we're not so sure.

When I get a chance to look at it again, I'll try to get that file uploaded.

 

I know a friend had similar issues with his AEM and it ended up being the wrong wire hooked up. IE he had blue hooked up when it needed white, or the other way around.

 

If the signal wire is spiking to 18v, something's not right. It should be 0-5v.

 

Yep, thats the problem.

EDIT: Dummy in charge of DVM had the thing in A/C, not D/C

Now we can't get the msq going - error message just says upload failed.
Ditto on what the dogg said.

 

Partner in crime had volt meter set to AC instead of DC. Holy crap.



Embarrassing.

Doesn't really explain the frozen wideband signal in Tuner Studio, but I did verify that the signal wire is giving a healthy 0-5v as it should.

The laptop is really sluggish. I have a log, I'm just trying to get it to load on the laptop I recorded it with so I can make sure it's showing what I'm describing.

EDIT: Okay, just downloaded the Megalog viewer onto the desktop, and the file will play for me on the desktop, but I can't get it to load to this forum.

 

Does someone have an email or something they want to PM me so I can get another pair of eyes on this data log? It's probably something else I'm doing, but I can't get the file to upload to the forum. Thanks.

 

hi_im_sean@hotmail.com

wont be able to do anything unitl i get home in a couple of hours

 

Looks like Henry had misclicked wideband controller type during setup. He said he'd already set up all that, so I focused on underhood/wiring stuff.