E30 Zone

I have an e30 with an m52b28 conversion done by the chaps at fritz bits. It has been fine for ages and never had any running problems except for a dodgy thermostat that cause it to stall occasionally.
I fitted a pipercross viper carbon fibre enclosed air filter thing so it didnt suck too much hot air in with the pipe sucking air in from behind the headlights.
I had this filter on there 8 years and I thought it would be a good idea to clean it.
However I made a bad job of cleaning the filter and it was also not fully dry when I refitted it.
I left the thing to stand for 5 days to dry and felt dry.

After putting the filter back on I stated the car with the MAF disconnected. The car misfired and wouldnt run right.
I then noticed my error plugged it in and restarted the car.
The car then ran badly, misfired and stalled on the test run.
I then took the filter and maf off to find it all coated in black oily residue.
I then cleaned the maf, cleaned the filter again.
I then put the maf back on the car with an old K&N cone filter.
Ran the car and it still had problems
I plugged in my laptop with the bmw inpa software and it came up with MAF error one of which said short circuit.
Plus other error that are due to conversion like exhaust flap and speed error.

So I cleared the error as I assumed it was from when the sensor was contaminated.
I tried it again still didnt run properly. Kept doing little hiccups and stalling.
The maf error returned. I assumed I had broken it by contaminating it.
I have now fitted a good maf and the error still comes up.
I am wondering what I have done wrong, I am at a loss and I also hope that I have not broken the other maf as I borrowed it while I was waiting for a replacement to come from those efficient German chaps at autodoc.

The car was running absolutely fine before I tried to clean the filter.

Hope someone knows what I have done wrong.

I suspect the aftermarket filter is your problem, they dont filter the air properly as it is but now you have soaked it the dust/particles have loosened enough to be pulled through by the intake, as the MAF uses a very thin and fragile hot film wire to calculate the mass of air any impacts by crud will either cause a faulty reading or worse break it which will give a 'short circuit' error.
You should be able to see the wires by looking into the MAF, beware of aftermarket branded MAF's as there are loads of cheapo 'reconditioned' units around that have just had a resistor soldered in place of the hot film wire.

In my experience K&N type filters are never worth cleaning, just bin them and replace. Personally I do everything I can to avoid them and use a standard paper filter, the end result is your engine will last longer

Hi Dan

Yeah, I wish I had just replaced the pipercross filter. But they are Jolly expensive.
I would like to use an airbox type oem standard filter arrangement however my car has abs and I dont think there is enough room to fit the e36 airbox arrangement.
The car came from fritz bits with the K&N cone filter that I have fitted now, this filter has never been cleaned, to my knowledge and worked on the car fine for a couple of years until I got the shiny carbon fibre pipercross filter.
So you think I have totally toasted the borrowed MAF.

The first maf I broke which was the one that has been on there since the conversion was done, is an after market type which had a resister and a wire instead of the 2 dissimilar metal films.
The car seemed to run fine with it.

I am wondering if have not put all the pipework back together properly.
I read on a forum that an air leak can throw up a maf error.
None of the wire films are broken in either maf.

If its a short circuit fault there is a break somewhere, could be a broken wire leading up to the MAF if its not the MAF itself

I think you may be right about a dodgy connection or wire,
Today i ran the car stationary and it was fine I got the real time analogue values on the inpa.
the voltage across the MAF was changing nicely in spec.
the air flow reading from the MAF was high but as the car warmed up it came back onto the scale.
However the icv was off the scale, It has identical reading to the maf reading next to it. dunno if this is normal because of the m50 manifold and just the lack of the breather valve.

so then took it for a test drive and it played up few hiccups and stalled a few times. I haven't checked to see if the maf error has come back yet.

I also forgot to mention that when it first contaminated the maf. when i put it all back together and cleared the error codes i also cleared all the adaptation.
I've now read some posts that this is a bad idea and should not be done and can cause running problems and unusual error for parts that are working correctly.

Also Dan, is it possible to get an airbox in there with the abs pump? I also have the rad with the integral expansion tank, that is on that side.

The only issue clearing adaptions can cause is if the adaption are working to their limit masking a problem. You can fit an e36 filter box but it needs cutting up quite a lot