MAF sensor

[rmoconnor41]

I have an on going issue with the 2.8 idling poorly from cold.

We have been working on looking for potential air leaks. The latest on was a split in the CCV pipe.

I did wonder if the MAF might be contributing to this. It was replaced several years ago with one made by NTY.

Removed MAF today and cleaned it. Possible slight improvement.

If I unplug the MAF the engine stops. Shouldn’t it default to factory settings and still run?

thanks for any suggestions you have.

 

[Zephyr]

As fas as I know when the MAF is not connected the ECU turns into an Alpha-N mode as you say.
It does not calculate any parameters and just runs on presets.
you are unplugging while the engine is runnin from what I read
Have you tried unplugging the MAF and then start the engine?
Does it behave differently on each case?

 

[rmoconnor41]

As fas as I know when the MAF is not connected the ECU turns into an Alpha-N mode as you say.
It does not calculate any parameters and just runs on presets.
you are unplugging while the engine is runnin from what I read
Have you tried unplugging the MAF and then start the engine?
Does it behave differently on each case?

Hello thanks.
Yes it will start and run if the MAF is unplugged first.
It runs really roughly a bit like it did with the air leaks we found.
Richard

 

[NZ00Z3]

Sounds like you have some more vacuum leaks to find.

With the MAF unplugged, the engine should run smoothly but rich. This richness will mask some small vacuum leaks at idle. You have an engine that is running rough with the MAF unplugged, so there are still more vacuum leaks to find.

Easiest way to find a vacuum leak is to smoke test the engine. Read: https://www.e46fanatics.com/threads/how-to-smoke-test.1261077/#post-18615547

 

[DomiMik]

I did wonder if the MAF might be contributing to this. It was replaced several years ago with one made by NTY.

I would recommend to buy a decent MAF from Continental/VDO. Aftermarket sensors are known for causing trouble so forget about the cheap stuff, no matter if it's from Hella, Bosch, Febi or whatever.

 

[Lee]

Echo the above Rich, she needs a smoke test just as we last spoke about.

MAF's on this gen engine really don't like aftermarket units and they often fail within weeks of fitting.

 

[rmoconnor41]

Echo the above Rich, she needs a smoke test just as we last spoke about.

MAF's on this gen engine really don't like aftermarket units and they often fail within weeks of fitting.

I will probably return the Febi one then and try and source a Continental one. Thanks . Ant has offered another smoke test with his home made machine.

 

[rmoconnor41]

Sounds like you have some more vacuum leaks to find.

With the MAF unplugged, the engine should run smoothly but rich. This richness will mask some small vacuum leaks at idle. You have an engine that is running rough with the MAF unplugged, so there are still more vacuum leaks to find.

Easiest way to find a vacuum leak is to smoke test the engine. Read: https://www.e46fanatics.com/threads/how-to-smoke-test.1261077/#post-18615547

The car is quite lumpy from a cold start with the revs all over the place if the MAF is unplugged.

 

[rmoconnor41]

Lee, If you whatsapp me perhaps we can arrange a date to track down the leak.
Thanks
Richard

 

[Lee]

Lee, If you whatsapp me perhaps we can arrange a date to track down the leak.
Thanks
Richard

Be a little while yet. I’m a couple weeks into my new job.