240 AMM Test (MAF sensor procedures)

[smeha]

Hello everyone,
I know for a fact of smelling occasionally unburnt gas that my car is running a little rich.
I don't have tester LED, so thats out of the question at the moment.
So far I know, injectors clean, timing 13@750rpm, no vacuum leaks.
Next on the agenda is to test O2/AMM/ECU.

I've seen here and heard that its about time for AMMs to fail. brickboard says that aftermarket is terrible and only BOSCH OEM.
The question of the day, how to properly test AMM?

I read sources below, but cannot understand isht:
https://www.brickboard.com/FAQ/700-900/EngineFuelinjection.htm#SettingBaseIdle
https://www.brickboard.com/FAQ/700-900/EngineFuelinjection.htm#TechnicalNotesonAMMCalibration
http://forums.turbobricks.com/showthread.php?t=280002
http://forums.turbobricks.com/showthread.php?t=13912

 

[EivlEvo]

Presumably this is on your 2.2 88 245?

 

[holtzboy]

The LED isn't require to test the AMM base idle mixture. You can use a voltmeter to check. It should be fluctuating between 0v and 1v constantly. 0v is lean and 1v is rich. If it is stuck at either end, turning the screw clockwise is lean, counter-clockwise is rich. Don't get discouraged if you can't get it to fluctuate right away. I've had to turn the screw multiple times and then went back the other way and it began to fluctuate.

 

[smeha]

Yes LH 2.2 Where do I test voltage? At AMM? ECU? Which pins? Thank you

 

[holtzboy]

There's a blue test point connector by the battery. One wire should be blue/white (Idle motor) and the other is pink (AMM test point).

 

[ZVOLV]

I have seen them spec out ok on a scan tool voltage wise (which is generally a different voltage than a dvom would read) and still be bad. I had a 01? Sentra in the above case that was stalling at idle and the new MAF fixed it.

Start with a cleaning. Or try another one.

 

[smeha]

I don't have a garage of spare parts, no stalling. Just seems I run a little rich

 

[ZVOLV]

I don't have a garage of spare parts, no stalling. Just seems I run a little rich

Does it pass smog? The CO numbers are good for seeing the mixture. I have a 1986 740 GLE that instead of being at about 1% CO it was over 6%!!! I believe it was an injector leaking. Hard starts, smoke, or driveabity?

How do you know it's rich?

 

[smeha]

Passes smog great year ago, but I got new CA cat and o2 bosch sensor, injectors were resealed and cleaned about 3 years ago or so. I just have a feeling and after high revs it smells a bit gas. I have new pumps and new OEM filter to main pump connector, so I don't think it's a leak. I do have a extremly small leak in exhaust near muffler

 

[smeha]

This is from June 2016 CA passed smog report, anything bad?

 

[ZVOLV]

Your CO is just fine, so it doesn't look rich to me. If you were lean the Nox would likely be high.

 

[smeha]

Fuel smell, where its coming from? it smells near outside form engine after high revs... No vacuum leaks and no fuel leaks on visual inspection.