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2001 STS
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427 Posts
Discussion Starter #1
My 2001 has developed an interesting starting problem. It turns over and seems to start but immediately dies. This happens 5 times in a row, and then all works again.

The only code I can pull is P0102 (which I think is MAF sensors low frequency). Could the MAF be causing this problem? Seems unlikely that MAF would have such an impact at idle...

Thanks
 

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2010 DTS
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I am not sure if a MAF sensor will do that or not, but since you are having a problem and that is the DTC that is stored, I'd have to go with it.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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71,004 Posts
Take it from a MAF experimenter: If the MAF is out of spec, the car will NOT run properly, if at all.

The obviously modified MAF represents close to $300 of money thrown away.......

Remove the intake resonator and get to the MAF connector. Check the 5 wires and the connector. MAF's are relatively bulletproof, so maybe a good cleaning with throttlebody (NOT choke) cleaner will help.
 

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2001 STS
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427 Posts
Discussion Starter #4
Ok sounds like a MAF cleaning is in order. What is the difference between throtlebody and choke cleaner? (I assumed all the same)

Thanks
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Chemicals - some say that the anodizing or surface treatment in the TB and butterfly is affected by "choke cleaner" as opposed to TB cleaner.
 

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2010 DTS
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FWIW I am still using Gumout carb cleaner just because I still have some and have had no ill effects.
 

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2001 STS
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Discussion Starter #7
Well, the problem is back. In November I cleaned the MAF really well with carb cleaner and I assumed I was in the clear. Now, 5 months later, it's back. Before I go out and buy a MAF (which I think is pricey), there's a couple of interesting clues. First, P0102 has reappeared again, and also at the same time as a no start condition (actually start then die immediately). Advice from another forum posting pointed to bad crank positions sensors, and I was about do that job as it gets warm outside (I'm in Canada)....and then this. Is there a connection? Could MAF be causing the start-die condition (not CPS)?

Maybe related, maybe not, I pulled the codes below. Anyone see something related? (There are so many codes that I will probably post them in a seperate post - I don't think these are related other than the MAF one).

Thanks!!

C1223 - Left Rear Wheel Speed Sensor Input Signal is 0
C1224 - Right Rear Wheel Speed Sensor Input Signal is 0
C1248 - EBCM Turned the Red Brake Warning Indicator On
RIM B1328 Vehicle system voltage is greater than 15.9 volts
MSM U1000 U1000 class 2 communication malfunction
IPC U1016 Loss of Class 2 Communication with PCM
IRC U1016 Loss of Class 2 Communication with PCM
TTM U1016 Loss of Class 2 Communication with PCM
TTM B1983 History - Device Circuit Power Low
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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None of those are related to the P0102, but I'm surprised that you don't have a "speed limited............" DIC readout with no rear wheel speed signals. The other codes relating to voltage and data are inconsequential - they come and go like clouds.

Remove the 5-pin connector from the MAF and loosen the 3 ducting clamps. Work the duct up and off the TB and remove it from the MAF. Remove the MAF and rubber coupler from the airbox/filter housing spigot. Carefully clean the MAF honeycomb and resistor bridges with TB cleaner spray - NOT choke cleaner. Careful of those 3 tiny heated resistors. IF that damn resonator is still stuck into the top of the intake ducting, is/was it seated properly ? - those things are the cause of all sorts of airflow faults. When you re-assemble the intake ducting make very sure the MAF is oriented correctly and that there are NO duct leaks - any leak from the MAF to TB sets mixture codes. That "screen" on the MAF is actually a 1/4" thick honeycomb airflow straightener - same as a wind tunnel - don't mess with it. The tiny black bead at the edge of the MAF bore it the Intake Air temperature thermistor.

Use a carefully trimmed rattle can top with s/s hose clamp to do this........it will make your engine checks and air filter changes less painful......(the clamp is on the airbox top corner because I was seating a new foam gasket........) Click on the thumbnails to enlarge.
 

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2001 STS
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427 Posts
Discussion Starter #9
I've though about moving the resonator, but I'm trying to keep the engine stock....

I recently removed the hoses and MAF to add ATF, so I'll check. I'll recheck the orientation - your picture shows your MAF and a different angle than I recall mine being...
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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The MAF will not sit in the position shown in my pictures unless you remove the resonator - which does nothing to modify the engine from stock: Removing the resonator increases intake roar at high rpm WOT - nothing else.

BUT, its removal vastly simplifies work and checks on the entire water pump end of the engine.................
 

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2001 STS
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Discussion Starter #11 (Edited)
Things are getting worse...

I rechecked tonight and all clamps were tight, all plugged in ok, etc. So I removed the MAF and cleaned it again with throttle body cleaner, reassabled, and reset the DTC's.

Now I get a P0102 after every start! Should I concluded I need a new MAF? Why is it suddenly worse?

I oriented the MAF so the big plastic divider on the output side is vertical - is that right? This makes the little black box on the side stick out horizontally...
 

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2010 DTS
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Things are getting worse...

I rechecked tonight and all clamps were tight, all plugged in ok, etc. So I removed the MAF and cleaned it again with throttle body cleaner, reassabled, and reset the DTC's.

Now I get a P0102 after every start! Should I concluded I need a new MAF? Why is it suddenly worse?
P0102 - Mass Air Flow (MAF) Sensor Circuit Low Frequency
That would be my guess.
 

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2001 STS
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427 Posts
Discussion Starter #13
Just more info...after reading every P0102 post I wanted to mention:

I checked the plenum and no cracks, all seals well. I cleaned the throttlebody with TB cleaner at the same time.

I have NO other codes. A cadillac mechanic in the forums said the MAF's rarely fail.

Hmmm....I would hate to spend $200 on a MAF only to get the same error
 
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