Broken MAF wire?

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Jul 10, 2005 | 11:25 AM
  #1  
I'm installing my CAI and suddenly I find my thumb straight through the wire on my MAF. Crap. They're $75+ and tough to find used in good condition. I tried every junkyard with no luck so I think i'm screwed. The wire is about the width of a piece of hair. So I realize I'm stuck at the house until I get a replacement, I decided to try to replace the wire. I found a piece of wire that was the same gauge. Well after 30 minutes of cursing its installed and the car is running great. Its easy if you have a VERY steady hand and some common sense. Probably not the best permanent fix but I am more than confident in driving it around for the next few weeks until I can find an affordable replacement.
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Jul 10, 2005 | 12:46 PM
  #2  
I would be VERY interested to know what wire you used to replace the hot wire. I tried this several years ago, and had some difficulty finding the PtNi wire used in the MAF. I ended up using a slightly different alloy and guage wire to retain the same resistance characteristics and thus the same heater current (and resultant output signal). My attempt was unsuccessful, since the MAF was no longer calibrated to stock levels. Output signal was about 60% of what it should have been at a given air flow.

I also had a very interesting time trying to resistance weld the sensing wire to the end support elements. Disassembling and reassembling the sensor was not that difficult by comparison.

If you "just happened" to have a piece of 41 AWG platinum/Nickel wire lying around, what other cool stuff do you have stashed in your kitchen drawer?
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Jul 10, 2005 | 01:19 PM
  #3  
I repair electronics for a living (mostly guitars, amps, pedals) so I have alot of wire. This wire however is probably not the same specs as stock. My car wide open runs awesome, but idle is a bit weak (although I've always had stalling problems so it may not be the MAFs fault). But I'm more than thrilled with the results considering I need to drive a few errands this week until I swap to a MAP setup. I soldered the wire to the terminals which isn't the best way to do it but it worked well. The wire was actually pulled from a bunch of ribbon cable I got from Allegro microsystems. They manufacture all sorts of components for cell phones and other devices (not that it's relevant).
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Jul 10, 2005 | 01:49 PM
  #4  
Of course it would run well at WOT. The MAF sensor is ignored at any throttle opening above 80%. Your idle and mid-range operation would be the real test. Did you meter the mV signal from the MAF at various flows? You should be around 900mV at a 850 RPM idle and closed throttle.

Soldering may not be all that durable, since the first burn off cycle will heat the wire to about 1,200°F . Unless you used silver solder, the sensing wire may just fall out. If you crimped and soldered to the end supports/contacts, it may survive.

I've got a day or two of electronic experience as well, and PtNi wire is about as common as Litz wire. I have seen it used in heater applications and some conductiveity probes, but not many other places.

Good luck until you get it swapped. The one saving grace is that the engine should at least run acceptably in Backup Fuel mode even with no MAF.
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Jul 10, 2005 | 02:09 PM
  #5  
I wrapped the ends around the base twice then soldered. Still there after a few runs luckily.
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Jul 10, 2005 | 03:04 PM
  #6  
About 20% throttle and under isn't the best (but still useable thats for sure), but over that it feels like it did all along. I really wish I had an A/F to see if I'm running lean/rich, but I never installed once since "they are stupid and useless".
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