[wildcat]

I  have successfully replaced the platinum wire in the MAF with a copper one and it works. There is a reason they use platinum, it doesn't corrode. If you've got some 22 gauge speaker wire strip a "long strand" from it, say 3 or 4 inches, solder one end at the first contact point, wrap it around the second and third posts, and solder the remainder to the forth post. Its tricky but you won't be doing it unless the wire breaks and you've got nothing to lose by trying...

 

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[Waylander]

Interesting


Wonder what the ECU makes of that ?

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[williamoss]

were you unable to buy a strand of Platinum wire?

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[flash]

interesting, but it seems like a lot of work for what is a relatively inexpensive part.  last time i checked, a rebuilt unit is only a few hundred bucks.  further, given that the wire has a very specific heat measurement requirement, i wonder how accurate it will be.  have you done any A/F measurements?

 

could be a fix, but having seen how touchy the tuning is on this car, i am not sure i would want to mess with it.

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[unknown4u]

What happens when the system is resetting itself by heating up the wire.... because that will happen from time to time. Copper can not. The platinum wire will heat up to 1300 degrees. Copper will melt i suppose...
The heatproces is because cleaning the wire.

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[Waylander]

Guess the answer will present itself eventually

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[wildcat]

Its gone through the heat process I think.  Initially the computer went through some kind of adjustment... the RPM's were a tad low and it stalled.  I started it again and it cleaned up. I think the wire had a thin plastic coating on it which appears to have burnt off.  In the picture you can see it shiny.  That was after the first time I ran it and took it out to take a picture.  Now its got kind of a dark rainbow color like its been heated.  Once I knew it was going to work I replaced the wire with a new one. Its a bit of a learning experience.  Its not easy to see in the tube, and the wire is so thin it disappears at certain angles. It wasn't all that much work just a little tricky.  The trick is to use a longer wire, solder that to the first post, then because the wire is long you can push it around the other two posts.  I didn't loop them as I've now noticed is done at the factory. Then tightening the wire for the forth post by wrapping it around, you hold it in position and with the solder iron tinned; the wire and post bond. Then clip off the remainder.  I did it at 2 o'clock in the morning the first time, I wasn't in the best of shape.

 

I realize there's a lot to a MAF and I have no way of testing any of it.  All I can say for sure is, it works and if there's any shortcoming it has been at idle. At worst it runs like a cold engine, which in fact it was, but I've not had that experience with this car.  Above idle it runs great.   I'm now testing the second "wiring" and on first try it started right up settled down to idle with no hiccups.  

 

I don't know where one obtains platinum wire, a jewelry store maybe... never soldered with platinum, it may require more heat than a solder gun produces. 

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[Waylander]

these are the same

 

AUDI 80 Avant (8C, B4)

 

can get those on ebay for $50

 

Bosch 0 280 213 007 will work

 

the one on the car is 0 280 213 017

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[Ryan]

The soldering gun only has to heat up enough to melt the solder, not the wire.

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[wildcat]

That would be a cold weld?   I belatedly discovered that the two bottom posts are split, the wire is pulled through the split and held by the tension.  You might see it with a microscope.  

 

Concerns raised about temperature and how conductivity might alter the signal.  (both legitimate concerns for sure)

 

Melting point

 

Copper  1,984 F  Platinum 3,215 F

 

Conductivity

 

Copper 5.96 x 10+7  Platinum 9.43 x 10+6

 

The car has to warm up to operating temperature or it stalls.  It would appear that at idle the injection is lean until it warms up.

 

As for running its fine, no lag, nothing to indicate performance is retarded.  (at idle its still a tad lean but doesn't stall when operating at temp.)

 

I'm not recommending this as anything more than a temporary solution which is fairly easy to accomplish. I can't be down for a couple of days waiting

on a part and I'm not burning money for expedience.

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[flash]

the car will "run" with the mixture out of whack, which is what happens with a MAF that is not right.  even a dirty one will make it run oddly.  while it may be a "patch" until you can replace it, i would not run it very long without verifying that the mixture is safe, and i definitely would not rev it very high.  if it's lean, you could easily burn valves, or worse, especially in this heat.  that would cost you a lot more money than a new MAF and certainly take more than a couple of days to fix.

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[94SilverCab]

I think what I hear Flash saying, is that there are a lot of ways that an item "could" be fixed, that perhaps are better not speculated on within this forum.

 

On a related note, I reattached my body panels with Duct Tape...

 

JMO,

 

Jay

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[wildcat]

I think what I hear Flash saying, is that there are a lot of ways that an item "could" be fixed, that perhaps are better not speculated on within this forum.

 

On a related note, I reattached my body panels with Duct Tape...

 

JMO,

 

Jay

Right, well its always easy to go buy a new part... but for some of us the experimentation and the "fix" are all part of the fun. But I appreciate your clarifying and will respect your wishes.

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[flash]

don't get me wrong.  i've definitely done my share of "rubber band and bubble gum" fixes to get me home.  but, when it comes to something that could essentially determine whether or not i blow up my motor, i'm not inclined to push it beyond getting home, without at least determining via some empirical data, that it was safe to run.

 

given the cost difference between platinum and copper, i am certain that there is a reason they used platinum.

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[williamoss]

For those like myself who do not know everything about our cars and rely on mechanics I offer the following article. 

 

(From Discount Autoparts.com)

 

 



PORSCHE 968 Mass Air Flow Sensor



Description


The Air Flow Sensor or Mass Airflow Sensor (MAF) is one of the components of an electronic fuel injection system and is found in many of modern vehicles. Most mass air flow sensors are one piece hermetically sealed units with no moving components.


Purpose
The Mass Air Flow sensor is used to measure (actually weight) the amount of air entering the engine. This measurement is used by the engine computer or ECM to calculate proper amount of fuel injected into the cylinders in order to provide optimum combustion and low emissions.


Maintenance Tips/Suggestions
PORSCHE 968 Mass air flow sensor requires no regular maintenance. On mass air flow sensors with a sense wire, this wire can become contaminated with dust particles. These particles can be removed with automotive solvents that are safe for the use on mass air flow sensors. PORSCHE 968 mass air flow sensors are commonly misdiagnosed. Before replacing the mass air flow sensor check for air leaks in the connecting air ducts and intake manifold. These leaks can cause similar symptoms as a malfunctioning mass air flow sensor.


Failure symptoms
Problems with Mass Air Flow sensors are common. Bad or contaminated PORSCHE 968 Mass Air Flow sensor can possibly cause a wide range of various vehicle drivability problems such as stalling, especially when the engine is cold, misfiring, poor acceleration, etc. In addition, a problem with the Mass Air Flow sensor often causes the "check engine" or "service engine soon" light in the vehicle instrument panel to illuminate.


AKA
MAF, Air Flow Meter


Location
The PORSCHE 968 Mass Air Flow sensor is usually installed in the intake air duct between the air filter and the throttle body mounted on the intake manifold. Some mass air flow sensors are mounted directly to the throttle body.


Disclaimer
Depending on the year and options your PORSCHE 968 has, the above information may not apply. Consult with a professional automotive technician or manufacturer for specifics on your PORSCHE 968


- See more at: http://www.discountautoparts.com/autopag...TS6Ez.dpuf

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[wildcat]

I've checked the price on platinum wire and "thermocouple" wire .002" runs about $2.00 an inch.  Shipping is around $8.00 ground. Maybe it can be found locally.

 

The failure symptoms mentioned can be simulated by disconnecting the plug from the MAF.  

They can also appear when the sensor is contaminated. The sensor is supposed to be self cleaning.  The wire is heated up periodically which burns off the contaminants. The mention of the use solvent without qualifying what type is irresponsible.

 

Platinum has a much higher thermal conductivity than copper.  When the engine reaches its operating temperature, so does the copper wire. The car runs fine at operating temperature.

I've not had the check engine light come on which would have been a caution for me.

 

Speculating on what might happen is still "speculating".  B)

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[flash]

again "runs fine" can only be verified with tests.  it can start, stop, and go from point a to point b and still be dangerously lean.  show me A/F readings and i'll be more inclined to buy that it "runs fine".  until then, please stop "speculating" on how it runs.

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[94SilverCab]

http://shop.advanceautoparts.com/p/crc-m.../7070079-P

 

I have seen CRC Mass Air Flow Sensor Cleaner used by professional mechanics with good results.

 

YHMMV,

 

Jay

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[Waylander]

these are the same

 

AUDI 80 Avant (8C, B4)

 

can get those on ebay for $50

 

Bosch 0 280 213 007 will work

 

the one on the car is 0 280 213 017

 

 

 just checked with the bosch catalogue 0280 213 007 has exactly the same physical and electrical properties, the only difference is two bolt mounts on the outer casing??

 

like a lot of Bosch parts, just brackets and mounts make it a different part number

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[wildcat]

When I say it runs fine... it runs fine. Your judgement as to whether it meets your standards is irrelevant.  I have accomplished something which hasn't been attempted and it is a success.  You infer its a "chewing gum and chicken wire" solution.  That is your rather narrow opinion. The point is it works - and one can fix their MAF with platinum wire for a lot less than they would have to pay to acquire a rebuilt one.   That is a positive thing by any measure.  Your paranoia is unwarranted.   

 

Dangerously lean??? Maybe in your supercharged model that has been a problem.  I have worked with carburetors before fuel injection and regardless of how messed up they were, I never heard of anyone burning up valves unless they were using nitrous oxide or some other high octane fuel.  Fuel injection coupled with the computers that control them eliminate the possibilities you imply with sensors that monitor and regulate the fuel. The MAF is one component in that system and its parameters must match those required by the computer as everyone whose had problems with their MAF can attest. Your conclusion is purely speculative based on  an erroneous premise.  

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