Frank@Work

Yesterday, while driving through heavy rain and with my lights popped up, I noticed that the signal comming from the MAF goes birzerk from 3.9 volts. Up to 3.9 volts everything is ok, but then it jumpes to 5 volts and it stays there.

The highest voltage I normally get is 4.3 volts.

Did I brake something?

Thanks!

Frank@Work

Yesterday I had the problem decribed above. This morning I had the same problem. This afternoon everything was like it should be!

I haven't got a clue what went wrong (and went right).

I will post some Zeitronix screen shots later.

Frank@Work

3th gear:

RKD in OKC

You think maybe the rain got your air filter wet and it cooled off the hot wire in the MAF? Later the air filter dried out...

Frank@Work

I think the heavy rain and popped up lights had something to do with it.

Is this possible?

RKD in OKC

Just pop up the lights and go look at the gap and where your air filter and MAF are in the opening that is made.

shmark

did it slow down?

Frank@Work

Today I definately concluded that a wet air filter will mess up the MAF signal! I went datalogging just after washing the car. During the washing I had the lights popped up to clean the lenses.

After the washing I went for a ride to get some more data and the car was running not as usual and leaner than before (± 13:0). The lights where closed. The MAF signal was erratic.

The only conclusion I can make is that the filter was wet and messed up the MAF signal. It might be a good idea to put some kind of deflector in front of the filter.

streckfu's

That's what I thought

special tool

Interesting.
Frank - if you have a piggyback, you should log the MAF signal both before AND after modification (by piggyback). You can use the the "user input" channel on your Zeitronix and simply multiply by 20 to equal the "MAF" trace.
Now - LOG THE egt (VERY IMPORTANT) and note what is happening.
Please post the results of this test, if you have the time.

Frank@Work

The measurement from today I did not save, but I do have the logs from the time that the filter got wet from the rain (see pictures above).

I can supply you a file with the MAF signal before and after modification, but I do not have a EGT sensor (yet).

Sorry.

docwyte

Unless you have pads and rotors on your MAF, I doubt you used brakes to break it.

Frank@Work

Ah, now I'm getting it!