Re: K & N filters and MAF\'s
It's possible that my "cure" was invalid. Anything's possible, it could have been the space aliens hiding behind the Hale-Bop comet causing it. But it's highly unlikely! (I almost always wear a hunk of tinfoil on my shirt to keep them away!)
I've put about 800 miles on it since - still haven't experienced the problem like before. She's running great, smooth, good power etc.
The oil I used, as well as the cleaner before oiling it, was from the official K&N cleaning kit. Their oil is red.
The K&N reply to it on the link - they say "failure" - the MAF did not "FAIL" - it apparently was just giving the wrong information, causing problems.
I didn't replace the MAF, I just cleaned it. I did not see any deposit on the hot wire itself (sensing portion) but the sides of the housing right next to the wire had a thin oily deposit on it. I rather doubt it only got on the sides without getting on the wire itself.
But remember the sides don't have the "burnoff" feature, they don't self clean. (Why would the engineers design in a "burn-off" feature if foreign matter on the wire has no bearing on performance?)
No MAF code was set - it was still working to the best of it's ability, it apparently just give slightly false information causing a lean condition.
Wiping the sides right next to the wire with a white rag revealed the deposit was red. (But could it have been those space aliens tricking me by spraying ATF on it?)
In fact, ALL of the ducting had that red oily film. When I'd previously cleaned the filter I'd cleaned it all as my standard procedure, so I know it had been clean.
The filter is a flat filter in the housing, air is drawn in from the bottom, goes through the filter, then up and out through a duct to the MAF, where it then goes through another duct to the intake manifold.
ALL the ducting had that thin film of redish oil, not alot, but it was there. I used brake cleaner to wash it out, (removed from the engine of course) then flushed it with 409 and water.
I even ran a rag down inside the manifild snout past the throttle body as best I could, and found that thin reddish film.
It could have been my mistake too - I might have over-oiled the filter. But I'd rather have too much oil, too much dirt capturing performance, than too little. Cleaning the MAF is preferred to sanding out the engine.
But don't get me wrong -- I am a believer in the K&N Filters - I run them on almost everything I have. My testing - although not done scientifically, have shown them to be far superior to others I've tried.
My test - use a paper element for awhile. Run a white paper towel down the snout or on the places AFTER the filter - carb air horn, ducting, inside the filter housing area etc - where only clean air is supposed to be. Notice the dust and dirt on the towel.
Now do the same test with the K&N - mine have always come out clean - or at least, much cleaner! Try it! Yes, you do get that slight oily residue, but that tiny amount of oil won't hurt anything (well, except a MAF obviously) - it may even help catch that stray dust particle that got through!
I'll still use the K&N's, just not with MAF sensors.
Note: The Air Temperature Sensor on those vans is also in the airstream right behind the MAF. That too may have been affected, as it had that oily film on it too. Could it be that was the culprit? I doubt it, I have a 95 Astro too with a K&N - the air temperature sensor is in the same place on it - but it doesn't use a MAF - it's the speed density system (MAP). It's never done it. BUT --???
As far as the ability to flow more air - the K&N may flow better - for the area of filtration, but if you still want a paper element, simply increase the filtered area. Use a larger diameter or taller element.
Remember - the internet doesn't reject words. Lots of sites claim the K&N is terrible (but notice theirs is always so much better.) Make your own test, draw your own conclusions.
He He -- I'm sure one can find an internet site that says the only way to have sex is once a year with whips and chains.
Make your own test, draw your own conclusons!