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  #1  
Old 02-15-2008, 09:14 AM
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need help with gasser for buddy in Iraq

I know this isn't diesel, but there are some great mechanics that hang out here and was hoping they could chime in... I am trying to help my buddy's wife while he is in Iraq...

Thanks to a Mazda forum I diagnosed and performed a PCV hose changeout successfully for my friends MPV. There was a visable hole in the hoses' elbow on the back of the engine. The husband is in Iraq, and she was getting the P171, P174 codes. While I had things apart, I sprayed some electronics cleaner in the MAF wires, and throttle body cleaner in the throttle body and plate area. I also cleaned other electronic wire harnesses I unplugged to do the PCV hose replacement. Everything worked great, but now when you crank it up ( I think just when it is cold) the idle goes up to like 1500 RPM, then down to 700, then back up, then back down in the course of 10 seconds, up and down....It eventually stops after about 2 minutes?
Without understanding much about the MAF, could I have damaged it with the cleaner, or can you think of anything else I could have gotten into...? I may have left some throttle body cleaner fluid in the body, without wiping it down real good...
Any thoughts? I will try to look at it this weekend. What should I look for....
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  #2  
Old 02-15-2008, 09:21 AM
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I just hd a conversation with a friend about their MPV....They recently went on a road trip from TX to GA, and 1/2 way through, the transmission would flare - sounds alot like your description, but at driving speed rather than at idle....He never told me if it surged like that at idle, but he fixed it on the road by installing a new throttle position sensor.

Just a thought.

Good luck!
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  #3  
Old 02-15-2008, 09:42 AM
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Could it be going to high idle due to the cold and for some reason dropping to normal idle right away? Then doing it over and over again until the engine warms up?

-Jim
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  #4  
Old 02-15-2008, 09:52 AM
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I was thinking tps also, but weird that it would settle out. IAC does strange things too. What are the codes translated into?
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  #5  
Old 02-15-2008, 09:56 AM
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TPS was the first thing that popped into my mind.

Careful, though. I was working on a friend's car (escort) with a high idle, changed out the TPS to no avail. Chased that problem for hours and hours. Turned out the replacement part was bad.
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  #6  
Old 02-15-2008, 10:33 AM
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Check the TPS connections and verify if there's cleaner left inside the TPS unit. Those things have an idle position sensor, plus the potentiometer that sends the signal to the ECU.

When the engine is cold, the ECU uses the coolant temp sensor to control idle through the idle valve to keep the engine at a higher idle to warm up. When the accelerator is pressed, the computer overrides the program for the warm up and uses the parameters defined by TPS and MAF.

If for some reason the connection in the idle sensor of the TPS is failing (intermittent connection) the ECU will override the warm up program in the same rate the connection fails, giving you idle fluctuations until the engine is warm and there is no warm up program required.

Did you followed me? This is quite complicated to explain in writing...
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  #7  
Old 02-15-2008, 11:06 AM
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they have that problem too

Quote:
Originally Posted by zeke View Post
I just hd a conversation with a friend about their MPV....They recently went on a road trip from TX to GA, and 1/2 way through, the transmission would flare - sounds alot like your description, but at driving speed rather than at idle....He never told me if it surged like that at idle, but he fixed it on the road by installing a new throttle position sensor.

Just a thought.

Good luck!
They have that problem too. The MPV (2003 era) had a Transmission control module, software TSB. To have it flashed and reprogrammed is $96. Mazda called it "shift shock". It has a 1-2 flare, and a 2-3 thunk.
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  #8  
Old 02-15-2008, 11:09 AM
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thanks all

Keep em coming.

Does anyone think I dicked up the MAF.....

really aside from unplugging a few elelctrical harnesses, and spraying the electronics cleaner on the MAF sensor wires, I didn't do anything else.


If I depress teh accelerator right away, are you saying it could go away since it is sensing idle from a different system?
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  #9  
Old 02-15-2008, 12:06 PM
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Quote:
Originally Posted by spugeddy View Post

If I depress teh accelerator right away, are you saying it could go away since it is sensing idle from a different system?
It might, however, this systems are temperamental... Have you tried this?

I don't think you damaged the MAF, I mean, you only sprayed the connections, right? Or did you tore apart the sensor, cleaned it and then reassembled it?

If the car is having this failure only while being cold and there's no check engine light on, this means the sensors might be working.

According to what you said, it seems the issue has something to do with the warm up program of the ECU.

Have you checked all the hoses you changed are in place and properly fitted? Maybe a hose loosen when she drove the car...
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  #10  
Old 02-15-2008, 12:37 PM
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If you did use throttle body cleaner on the MAF sensor you probably ruined it. Those are very sensitive and should only be cleaned with MAF sensor cleaner. You might try to reclean with the correct cleaner to see if it is only residue left behind but I would not hold my breath on that hope.

JOHN
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  #11  
Old 02-15-2008, 12:42 PM
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electronics cleaner

No, I used Electronics cleaner from Radio Shack on the MAF wires... I didn't take it apart. Just took it out of the air hose assembly and sprayed it. It didn't look dirty before or after....
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85 300CD Turbo "Das Polluter" 230K sold for $3,000

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  #12  
Old 02-19-2008, 05:57 PM
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Spugeddy, any luck on your buddy's car?
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  #13  
Old 02-20-2008, 01:50 PM
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not sure

not sure if it is better.. I did remove the IAC and it was cruddy inside. I sprayed carb cleaner and operated the "plunger"

It moved more freely after I cleaned it...

I started the car up fine, but the engine was warm, and I think I have to test it on a cold engine....

I hope that did it, because is was sooooooooooooo easy.....
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  #14  
Old 02-21-2008, 05:20 PM
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Hope this got the issue solved. Drop us a note when you know this is final!
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