Electronic Mass Air Flow Sensor

Thu Feb 02, 2012 5:20 am   

I'm running out of luck with the car groups, and thought maybe one of the electronics gurus here might point me in the right direction with this.

I'm looking to buy (or preferably repair myself) a mass air flow transmitter from a 1990 Mitsubishi Eclipse (same as Eagle Talon, Plymouth Laser). This one's DOHC non-turbo.

Here's the sensor:
http://tinyurl.com/MassAirFlowSensor-90-Eclipse

New part is $650, used is $450. None at the local junk yards around here.

Anyone have any tips on rebuilding one of these or know anyone who can do it for less than $200?

Thanks in advance.

Bob

Fri Feb 03, 2012 12:43 am   

Guv Bob wrote:



It seems anything electronic on a car these days gets a large price tag.

I recently converted a diesel fuel control module that mounts on the
engine over to a stand alone unit on the firewall. It seems that this
was once done before however, the source dried up. This was for a GMC
pick up truck.

In your case, you should maybe investigate the inners of the
defective unit. You must have some one you know around you that is handy
with electronics? Air flow sensors are pretty easy to do, you could have a
vane type to spins shaft with a sensor or generator, thermo
displacement, ultrasonic or just a simple shutter type attached to a
position sensor. etc..


Get your hands on a broken one or something if you can't free up your
car to look into this.

Jamie

Fri Feb 03, 2012 2:15 am   

On Wed, 1 Feb 2012 20:20:55 -0800, "Guv Bob"
<guvbob2003_at_yahooooooooooooooo.com> wrote:


Broken link. Nobody home. Try again please.


Ouch.


Start with some rhetorical questions:
Are you absolutely sure that it's the MAF that's busted?
Have you cleaned the electrical connections?
Do you have any test equipment such as a EDB2 scanner, DVM, or scope?
Do you have any automotive repair experience?

According to Google search, the Mitsubishi Eclipse uses a Karman
vortex sensor. I'm not sure if that's correct. See:
<http://en.wikipedia.org/wiki/Mass_flow_sensor#K.C3.A1rm.C3.A1n_vortex_sensor>
<http://www.autoshop101.com/forms/h34.pdf>
<http://www.youtube.com/watch?v=gd640ImE9Ec>
<http://www.youtube.com/watch?v=NRIDW0xRmYo>
<http://www.ehow.com/how_5163433_repair-mass-air-flow-sensor.html>
<http://www.popularmechanics.com/cars/how-to/repair-questions/3297276>
<http://www.youtube.com/watch?v=nNpwk3qtZok>

There's a limited number of things that can break in such a simple
device. When you post a URL that work, I can suggest where to stick
the oscillosope (for the vortex type sensor) to see if there are any
pulses coming out, or where to stick the volts guesser (for the hot
wire and thermistor type) to see if either is busted.

Incidentally, I fixed the MAF on my neighbors Mitsubishi something. I
removed it, cleaned out all the soot, tar, dirt, and filth with a
bursh, cleaned the contacts, reset the ECU, and saved them a few
hundred dollars. However, that was a hot wire type, which uses very
tiny platinum wires. Touch them with a heavy hand, and they'll break.
<http://www.youtube.com/watch?v=wFTP4TzMLxE&feature=related>
Note that you really don't want to use any really strong solvents or
ones that leave a residue. Use the right cleaner:
<http://www.amazon.com/CRC-05110-Mass-Sensor-Cleaner/dp/B000J19XSA>
<http://www.youtube.com/watch?v=wFTP4TzMLxE>




--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Fri Feb 03, 2012 2:21 am   

On Thu, 02 Feb 2012 17:15:55 -0800, Jeff Liebermann <jeffl_at_cruzio.com>
wrote:

One more. This one offers diagnostics that can be done with a scope
and DVM.
<http://www.youtube.com/watch?v=sSuL58YEH-E>
Plenty more on YouTube.
--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Fri Feb 17, 2012 7:53 am   

"Jeff Liebermann" <jeffl_at_cruzio.com> wrote in message news:2vbmi7tc3h14j733nult26usv75mf8j0pk_at_4ax.com...

Seems to work for me. Here's the target....
http://www.redlinemotive.com/store/replacement/wizard.asp?year=1990&make=MI&model=ECL--002&category=B&part=Air+Mass+Meter


No, but 3 mechanics said that would their first guess, including the dealer.

I found one online for $169, replaced it. Some improvement, but still runs rich at cold or hot idle and at road speed.


Yes, checked and cleaned those and all the vacuum connections I could find.


DVM only but don't know what to check or what voltage/current. I was told this air sensor modulates an output frequency and not voltage or current. Don't have a frequency meter.


Shade tree mechanic. Pretty fair with pre-computerized systems.


Many thanks - I'll check each one! Had to take a break from the car repair (on the honey do circuit this week) Will be back on it in a few days.


Glad you posted all this. I'm not that advanced, but here's my fix-it story. This car died about 10 years ago and the mechanic isolated to the compuer. At that time it was $500+ for a rebuilt. I took the computer home and open it up. Smell a burnt capacitor -- if you've ever smell one, you never forget it. Pulled it and replaced it for 10-cents. Put the computer back in and it's still running 10 years later. Look up dumb luck in the dictionary and you'll see my picutre. LOL!!!


My favorite of all mascot is the UC Santa Cruz banana slug. What a sense of humor they have! Beats the tar out of the UC Irvine Anteaters. LOL!!!

http://www.ucsc.edu/about/mascot.html

Bob
Still slugging way (ugh...)

Sat Feb 18, 2012 1:01 am   

On Thu, 16 Feb 2012 22:53:52 -0800, "Guv Bob"
<guvbob2003_at_yahooooooooooooooo.com> wrote:


I always worry about asking people that have a vested interest in
selling you a replacement part or installation service.


New, used, or "refrubished"? Seller refurbished usually means they
cleaned off the grease and dust.



My guess(tm) would be the oxygen sensor. Bosch sucks. Get Denso or
if unavailable, Walker.


The ODB2 scanner is vital as it will display the error codes produced
by the ECU. They're can be found for as little at $25. Best of the
bunch plug into a laptop, but cost $150. You can watch your mixture
change as the engine warms up.


Stone age engines were easy compared to todays computerized
nightmares. We're both at the same level. Auto maintenance is a
survival requirement in todays world. My Learn By Destroying
education tends to be rather expensive but functional. As a last
resort, I've degenerated to reading the manuals.


Some of the video cover what looks like your MAF sensor.


Nicely done. I've fixed black boxes this way before. When replacing
caps, I try to use a higher voltage rating than stock.


Good things happen ocassionally. My version is that my ability to
repair things is cyclic, much like a biorythm. Some days or weeks, I
can't fix anything. A bit later, everything I touch, magically fixes
itself. I'm sure there's a reason, but I don't want to know.


Well, it almost took a student protest and stike to make the official
mascot a banana slug. The adminstration didn't like it, and offered
some other animal instead. After a referendum, the students won.
<http://en.wikipedia.org/wiki/University_of_California,_Santa_Cruz#Mascot>
I liven Ben Lomond, where banana slugs are everywhere. Nothing like
having one leave a trail of slime across the wall. They also prefer a
diet of Motorola service manuals and sticky box labels, both of which
I sometimes find chewed to shreds.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl_at_cruzio.com
# http://www.LearnByDestroying.com AE6KS

Mon Feb 20, 2012 8:08 pm   

A blocked catalytic converter will cause things like this. The
computer is struggling to keep up with the problem!

On Thu, 16 Feb 2012 22:53:52 -0800, "Guv Bob"
<guvbob2003_at_yahooooooooooooooo.com> wrote:

Thu Mar 01, 2012 4:03 am   

"John Ferrell" <W8CCW_at_arrl.net> wrote in message news:kd65k79l5sp3nao0gmib34b11ajmq7m9gm_at_4ax.com...

Thanks John. Will be the first thing I check this weekend. A buddy here said he had a similar problem caused by a rat buidling a next in the tail pipe. Would really be nice to look in there and see a rat grinning back.

Sun May 20, 2012 7:21 pm   

"Guv Bob" <guvbob2003_at_yahooooooooooooooo.com> wrote in message news:HrGdnet4UKaKetPSnZ2dnUVZ_uOdnZ2d_at_earthlink.com...
"John Ferrell" <W8CCW_at_arrl.net> wrote in message news:kd65k79l5sp3nao0gmib34b11ajmq7m9gm_at_4ax.com...

Thanks John. Will be the first thing I check this weekend. A buddy here said he had a similar problem caused by a rat buidling a next in the tail pipe. Would really be nice to look in there and see a rat grinning back.


Finally after several weekends of checking and minor fixes, so real progress...

Took the ECU apart and saw corrosion around 2 capacitors. Scrubbed the board and other board connections looked OK. Replaced the caps with same only 105 deg instead of 85 deg. All symptoms gone at engine cold start. Fine when hot, except when in neutral idle speed cycles between 1300 & 1500 rpm with about 1/2-second cycle time. This is only when up to temp.

TS guides say that's likely in the intake air flow -- mass air flow temp, press or flow sensors, idle speed air sensor, motor, etc.

I'm so jazzed that the main problems are solved that I'm going to call it a day and go have a LARGE burger AND fries!! Maybe even a Bladder Buster to drink. LOL!!!

Bob