Miller MAF Conversion Gen III troubles - running extremely rich

[Aahj]

Hey Guys,

Did some searching with no luck and thought I'd reach out to the group.

Just installed a Miller MAF Conversion Gen III on my stock 1987 325is.

It's running extremely rich, raw fuel pumping right out the exhaust.

I found the MAF troubleshooting document on their website and performed the necessary tests. I've confirmed I have battery voltage at terminal 3 on the AFM plug. I've also confirmed I have 1 Volt at terminal 2 with the key in the on position.

The question I have is what the proper reading should be at idle with the engine running. I'm currently reading 2.1 Volts when it calls for 1.5 Volts. Also, as I rev the engine up, it seems to only max out at around 5 Volts. Is this correct?

I've also tested the TP sensor and everything reads as it should when at idle, partially open and at WOT.

Any suggestions would be greatly appreciated!

Thanks,
AJ

[Todd Black 88]

Iirc, and I sometimes don't, idle should be between .8- 1.1 volts( or it was on my m3 kit)
The signal is a 0-5v signal so that is the max.

Sorry cannot help. Have you driven it to get it to adapt yet?

[Aahj]

Yes, I did drive it/run it for 30 minutes to see if it would clear up. No luck.

Also, the new MAF sensor needs a 12V reference. The old AFM uses 5V.

Thanks,
AJ

[Todd Black 88]

No, I don't think so. You need to feed the Maf 12 volts, that's why you tap the line at the ecu, but the Maf gives a 0-5vdc signal back to the ecu.

[Todd Black 88]

Deleted

[Aahj]

Got it. I've been in touch with Miller as well on this. Will definitely report back what we find.
Thanks again,
AJ

[travish325]

is the maf connector on upside down?

[Aahj]

I did check that and no it's not.