Rebuilding a Mass Air Flow Sensor

This has absolutely nothing to do with RCM, but you fellers are the highly intelly gent, worldly types (not unlike my self... hyuk hyuk) only smarter.
Anyway, I need to either figure out how to rebuild the air flow sensor assy on an old Eclipse or shell out $400+ for a rebuilt one or donate it for next to nothing off my taxes.
Anyone have any tips on rebuilding one of these or know anyone who can do it? I got no responses from the car groups, and thought maybe one of the electronics RCM gurus here might point me in the right direction with this.
It goes on 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.
Thanks in advance.
Bob
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Guv Bob wrote:

an old Eclipse or shell out $400+ for a rebuilt one or donate it for next to nothing off my taxes.

I got no responses from the car groups, and thought maybe one of the electronics RCM gurus here might point me in the right direction with this.

From my Favorite Auto Parts Place, rockauto.com:
A-1 CARDONE Part # 7460000 Remanufactured     Price    Core    Total     $188.79    $18.00    $206.79
STANDARD MOTOR PRODUCTS Part # MF0426 Remanufactured     Price    Core    Total     $207.79    $40.00    $247.79
BECK/ARNLEY Part # 1570192 Remanufactured     Price    Core    Total     $308.99    $25.20    $334.19
BOSCH Part # 63030 Air Flow Meter - New * Non-stock item--shipping delayed up to 2 business days     Price    Core    Total     $522.89    $0.00    $522.89
AIRTEX / WELLS Part # 5S2647 - New EXC. TURBO * Non-stock item--shipping delayed up to 2 business days     Price    Core    Total     $640.79    $0.00    $640.79
--Winston
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Guv Bob wrote:

Well, the pic shows screws on it, so it looks like it can be taken apart. What type of mechanism does it use? Old ones used swinging vanes and a potentiometer, most new ones use a venturi and a differential pressure transducer. Possibly dirt or bugs have blocked passages in it, that could be easy to fix.
What is the symptom?
Jon
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Guv Bob wrote:

Not easy to rebuild them without having access to the parts that fail. As Winston said you can get a reman MUCH cheaper or if you could live without it for a week or so there are a couple outfits that do rebuilds on your part and ship it back.
What is the problem you're seeing that tells you the current unit is bad?
--
Steve W.

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Thanks fellers. I just started looking at it so not much info yet. Don't know if it is hot wire type or not. Symptom is from my long-time mechanic -- says it could be MAF or could be computer - can't tell which. When hot or cold, car runs way too rich and will stall out if throttle is released.
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First, I'm not familiar with the 90 Eclipse... and this is just my 0.02 hunch with the limited info available in this thread.
Having said that... did your mechanic pull a computer code referring to MAF issues or have any other evidence of it's failure? (The car may be too old to produce Diagnostic Trouble Codes (DTC's)... I just don't know off the top of my head. Do you have the factory shop manual???
Running rich like that could just be a bad coolant temperature sensor or it's associated circuitry. Often times when they fail, or if their circuit becomes 'open', they erroneously report temperatures of like -40F[1] to the computer; which in turn will run the engine very rich... just like it's supposed to do. Terminal corrosion is one common cause of open circuits.
Coolant temp sensors are chump change in comparison to MAF's.
IMHO I think you really should do a little more investigating/troubleshooting first.
Good luck! Let us know how it comes out.
Erik
[1] Just out of passing interest, note that -40F equals -40C! Check it out!
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Thanks, Erik. No error codes on the connector.
Something else -- the car ran fine a couple of months ago and passed the annual smog test with no tune up or adjustments. Then it sat for about 2 months without being started. Recharged the battery and that's when the rough idle started. Reset the computer and no change.
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Guv Bob wrote:

I would check REALLY close for mouse damage to the wiring, and rust/corrosion on the connections. Just setting still shouldn't damage the MAF unless a mouse was using it for a home. I would also run a good injector cleaner through it. Setting that long can make gas into really bad crap. Could be that some of that is holding injectors open enough to cause the problem as well.
--
Steve W.

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Steve, the car is OK to sit for awhile. Where would I find a place to rebuild it?
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Guv Bob wrote:

Guv, you pay a core charge and send your old sensor back when the new unit arrives. They refund the charge afterword. Nearly zero downtime.
From my Favorite Auto Parts Place, rockauto.com:
A-1 CARDONE Part # 7460000 Remanufactured Price Core Total $188.79 $18.00 $206.79
STANDARD MOTOR PRODUCTS Part # MF0426 Remanufactured Price Core Total $207.79 $40.00 $247.79
BECK/ARNLEY Part # 1570192 Remanufactured Price Core Total $308.99 $25.20 $334.19
BOSCH Part # 63030 Air Flow Meter - New * Non-stock item--shipping delayed up to 2 business days Price Core Total $522.89 $0.00 $522.89
AIRTEX / WELLS Part # 5S2647 - New EXC. TURBO * Non-stock item--shipping delayed up to 2 business days Price Core Total $640.79 $0.00 $640.79
--Winston
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Guv Bob wrote:

Standard offers R&R through a couple places. Rock Auto being one of them. Think it's like 150 bucks or so.
BUT I would test it first to make SURE that it has a problem.
--
Steve W.

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Here's a bunch of photos of the assy out of the car: http://imageshack.us/g/513/gedc0177.jpg/
Looks like I need un-solder the connections on each side before I can open it and access the sensor.
This has absolutely nothing to do with RCM, but you fellers are the highly intelly gent, worldly types (not unlike my self... hyuk hyuk) only smarter.
Anyway, I need to either figure out how to rebuild the air flow sensor assy on an old Eclipse or shell out $400+ for a rebuilt one or donate it for next to nothing off my taxes.
Anyone have any tips on rebuilding one of these or know anyone who can do it? I got no responses from the car groups, and thought maybe one of the electronics RCM gurus here might point me in the right direction with this.
It goes on 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.
Thanks in advance.
Bob
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This has absolutely nothing to do with RCM, but you fellers are the highly intelly gent, worldly types (not unlike my self... hyuk hyuk) only smarter.
Anyway, I need to either figure out how to rebuild the air flow sensor assy on an old Eclipse or shell out $400+ for a rebuilt one or donate it for next to nothing off my taxes.
Anyone have any tips on rebuilding one of these or know anyone who can do it? I got no responses from the car groups, and thought maybe one of the electronics RCM gurus here might point me in the right direction with this.
Bob
This worked for me: http://www.autobarn.net/maairflsecl1.html
jsw
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wrote:

Have you tried cleaning it? CRC makes a spray cleaner just for the MAF. Have a hot wire/venturi type on the Ford van, engine idled like crap after an engine change. You will usually get rough running for several driving cycles after the computer loses the previous settings due to a power interruption. In my case, it never improved. The code reader pinpointed the MAF. I got the magic stuff, sprayed it down well and that fixed it. I was looking at a replacement, an $8 can of solvent fixed it instead. O'Reilly had the stuff here. CRC also makes some special cleaner for the upper intake manifold, which Ford says to never clean. A ridge of crud had built up at the butterfly, that took that right out and improved throttle response.
I don't believe the MAFs are rebuildable by mere mortals, I've seen no repair kits out there and it'd be tough to fix the filaments in there anyway. On Fords, you remove the square plug-in board attached to the venturi on the air box, chuck it and put on a new one. That's the cheap repair. The expensive one replaces the whole venturi assembly plus that board. There's an advantage to having a vehicle that millions were made of, at least as far as parts prices and availability are concerned. Replacement MAFs still aren't cheap, though.
Stan
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Bob, the likelihood that you'd find the _exact_ thermistors or resistance wire they use for the flow sensor is remote.
FWIW, sometimes they fail for accumulated grunge on the sensing elements. If your unit has resistance wires, be warned that you cannot touch them mechanically in any way, or you'll stretch or break them. If the unit uses thermistors (little epoxy bead-like things in the airflow), you can clean them gently with a soft brush.
But in either case, a good soaking in a mild solvent like denatured alcohol, followed by a rinse and thorough drying is about all you can do.
They truly don't fail very often. Most often, it's a false code because of other un-interpretable symptoms, bad connectors, or a bad harness.
LLoyd
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote in message

Mine had two problems, accumulated crud on the platinum wires and poor connection caused by unplugging it too many times to check the air filter for rodent damage. The connector isolated itself to an intermittent Check Engine light that cleared after pressing in only that one connector. The crud wasn't so obvious to the diagnostics but the engine ran smoother after cleaning it.
jsw
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On Wed, 1 Feb 2012 20:29:22 -0800, "Guv Bob"

an old Eclipse or shell out $400+ for a rebuilt one or donate it for next to nothing off my taxes.

I got no responses from the car groups, and thought maybe one of the electronics RCM gurus here might point me in the right direction with this.

I BELIEVE that is a Karman Vortex type air-flow meter - Rebuilding would be an EXTREMELY difficult project.
Bite the bullet for a good used one (if such an animal exists) or go for a new one. Other option is sell it to someone for the good parts that are left.
Cost of parts, and frequency of required replacement, is why Mitsubishi has to have that fantastic warranty to sell their cars - and why when out of warranty they are virtually worthless.
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snipped-for-privacy@snyder.on.ca wrote:

Could be a Karman Vortex type at that... interesting articles here:
http://en.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_vortex_street
http://en.wikipedia.org/wiki/Mass_airflow_sensor
Erik
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This has absolutely nothing to do with RCM, but you fellers are the highly intelly gent, worldly types (not unlike my self... hyuk hyuk) only smarter.
Anyway, I need to either figure out how to rebuild the air flow sensor assy on an old Eclipse or shell out $400+ for a rebuilt one or donate it for next to nothing off my taxes.
Anyone have any tips on rebuilding one of these or know anyone who can do it? I got no responses from the car groups, and thought maybe one of the electronics RCM gurus here might point me in the right direction with this.
It goes on 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.
Thanks in advance.
Bob
Last time you remember....... well, I swapped my MAS into another Eclipse and saw that it was OK, so that's good and bad. Now back to square one.
After a lot of tinkering, it starts and runs fine at road speed. Dies at idle and is idling rich. First thought was to manually adjust the idle mixture. Wrong. Can't do it on this car -- everything comes from the computer.
So I'm going to take another swing at it this weekend. Any suggestions from the wise folks here what to look at next?
Many thanks in advance.
Bob
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On 2/10/2012 11:50 AM, Guv Bob wrote:

and is idling rich. First thought was to manually adjust the idle mixture. Wrong. Can't do it on this car -- everything comes from the computer.

Hrmm.. If you have a known good eclipse, can you swap the brains out?
Tom
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