MAF questions

[Mike Rolica]

Ya, ECI  ..... Electronic cleaner injection Or STC   (switch to chevy <g>
:-)  he he.. couldn't resist!
Mike Rolica
Meridian Magnesium Products
Strathroy, Ont 
Ext. 260


	-----Original Message-----
	From:	David Cooley [SMTP:n5xmt at bellsouth.net]
	Sent:	Monday, November 29, 1999 1:22 PM
	To:	gmecm at efi332.eng.ohio-state.edu
	Subject:	MAF questions


	I have a question on MAF sensors in general.
	My 97 Explorer 5.0 is MAF, and the design of the Ford MAF is kind of
off 
	from what I'm used to on GM's.  It is a large bore with a sample
tube in 
	the middle (Actually open to the front of the maf in the top inside,
flows 
	straight down 90 deg. to main flow, then out the back into the flow
of air 
	again).  Just behind the inlet to the sample tube is the sensor
elements... 
	Look like light bulb filaments.  One in the air stream and one back
up a 
	bit so it's not in the direct flow of air.  I assume they either use
a 
	constant current generator and monitor voltage across the elements
(one for 
	reference) or constant voltage and monitor current.  The problem is,
they 
	are EXTREMELY sensitive to contamination...  I put in a K&N
airfilter 6 
	months ago, and every 1000-2000 miles, I have to clean the MAF
elements to 
	make it run right...  The last time, before I cleaned it, I was
monitoring 
	it with Alex's OBD-2 scantool...  at 5000 RPM and WOT, I was flowing
about 
	95 g/s air (definitely too low, thought the software for the
scantool was 
	wrong!).  Engine pinged like mad at anything over 1/2 throttle. (no
knock 
	sensor... Thanks ford!) Cleaned the MAF, and ping was gone...
Airflow at 
	5000 RPM and WOT was 196 g/s.  Is there any way to alleviate the 
	contamination problem (short of going to a paper filter or a MAP
based EEC)?
	Thanks,
	Dave

	P.S.  Ford Motorsports sells K&N's, so it's not like they don't use
them!
	===========================================================
	David Cooley N5XMT Internet: N5XMT at bellsouth.net
	Packet: N5XMT at KQ4LO.#INT.NC.USA.NA T.A.P.R. Member #7068
	We are Borg... Prepare to be assimilated!
	===========================================================