FED UP. electrical wiring woes inside M30 related

[Mr. Burns]

That's a shot with the old m20 tps.

[quickervicar]

Glad to hear it is fixed.

But why the constant 50% AFM reading?

[Mr. Burns]

Does cad mean dumbass in canadian?

Lmao!!!!! It so totally does.

Another zinger!

[LJ851]

I'm a bit of a cad.

Does cad mean dumbass in canadian?

[Mr. Burns]

I'm a bit of a cad.

I was running a m20 tps the entire time, the wires were simply reversed thinking it would work.

On a whim I plugged in a m30 tps (265) and all went well.

My guess is the incorrect tps was giving the open loop o2 readings.

So legit....this is finally resolved fir good now.

[quickervicar]

Just thinking out loud here, so forgive me.

The engine only measures the air passing through in two places, correct?

1) AFM on the way in
2) O2 sensor on the way out

If the AFM is stuck at 50%, I'd start tracing that down.

What injectors are in this thing? My 535i ran pig rich when I swapped out larger injectors without a software change. (long story)

[Mr. Burns]

Hate to be posting this but the problem id back.

Here's a video of its behavior.

https://vimeo.com/142938357

Is realize the video kind of sucks...
But it idles great however when gradually increasing throttle it hiccups and it's like the tps hits a flat spot between 1300rpm to about 3000rpm



Also at WOT it's like it hits a brick wall.

Values:

Air fuel mixture is stuck at 50%
O2 sensor readings arent fluctuating properly... go from 0.450mv to 0.520mv...




I'm open to anything now.

It's not mechanical it's electrical

[lukeADE335i]

Good stuff! I love it when problems turn out to be simpler than first thought :)

[quickervicar]

Awesome

[Ether-D]

Yes!! Good to hear man.

[Mr. Burns]

BOOM! RESOLVED!!!! traced back to simply a loose connection at the fusebox....

didn't need to replace the harness afterall.

[lukeADE335i]

The link mostly focuses on e28s, but it all applies to the Moronic 1.3 system too.

It's a comprehensive step by step to troubleshoot the Motronic.

[Mr. Burns]

It sounds like you're having normal Motronic issues... don't give up (the Megasquirt will be a world of pain vs just troubleshooting the Motronic).

If it runs pig rich at all times, are you sure the spring in your AFM is adjusted correctly? Also, is the O2 sensor working correctly? Are the injectors leaking or stuck open? Is the thermo switch for the Motronic working? etc.

I ran mine without the O2 sensor for a while and it ran ok, just on its base maps, but with a properly working 02 sensor, it was a noticeable difference in drivability once the computer had adjusted the injectors.

I've had mine on the dyno to check emissions, AFRs etc. and the Motronic 1.3 worked perfectly with the M20 harness.

The best Motronic troubleshooting guide I've found is here:

http://www.hiperformancestore.com/motronic.htm

Good luck! It'll work out :)

it's not MAF as I've swapped them out, O2 sensor is the proper one and (supposedly) working correctly
haven't put any thought or research into the injectors tho...

thanks for the link:D haven't checked that one our yet

[lukeADE335i]

It sounds like you're having normal Motronic issues... don't give up (the Megasquirt will be a world of pain vs just troubleshooting the Motronic).

If it runs pig rich at all times, are you sure the spring in your AFM is adjusted correctly? Also, is the O2 sensor working correctly? Are the injectors leaking or stuck open? Is the thermo switch for the Motronic working? etc.

I ran mine without the O2 sensor for a while and it ran ok, just on its base maps, but with a properly working 02 sensor, it was a noticeable difference in drivability once the computer had adjusted the injectors.

I've had mine on the dyno to check emissions, AFRs etc. and the Motronic 1.3 worked perfectly with the M20 harness.

The best Motronic troubleshooting guide I've found is here:

http://www.hiperformancestore.com/motronic.htm

Good luck! It'll work out :)

[Mr. Burns]

Furthermore...to add to the issues...

Body harness plug(c101) is female on e30.

My M20 harness fit perfectly with its male c101.

M30 harness is female engine harness C101...what gives.