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Discussion Starter #1
My car has been acting very unusual lately. It will die out then refuse to start and the theft light will blink and the pcm makes this buzzing noise. It also bucks a lot when cruising sometimes. I was thinkin its the tps cuz someone said they had the same symptom but had a code as well. I have no codes but I do know the iac needs cleaning. Also I changed the fuel filter and plugs months ago. When the car dies and the pcm makes the buzzin noise the odometer is just dash lines. Does anyone have a clue what this may be?
 

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your theft device is going out. If it does it again, open the door close it, hit the theft device and if your car fires up, then i would look at getting it removed. Your chip in the key could also be going out. I have a back up key just for that reason. sometimes it works sometimes not, but it still unlocks the doors. not sure if you can get the chip in key checked.
 

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Discussion Starter #3
This might be it but its weird that the bucking issue persists and I'm not sure if they're related. It seems like when the engines cold its fine but as soon as it starts to heat up the bucking/stalling/theft thing begins. I listened to the fuel pump while operating it makes a whiring noise so I think its good but I better test fuel pressure. I wish my car would throw me a code and make my life easier lol
 

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no code is a good thing. well except im leaning more to the antitheft device is shotty. I looked at a 2000 cobra that the guy played the bs game with me. I got into car just looking and he handed me the keys. the engine wouldnt do anything. He said take key out hit button close door and it will start. It did, but on the test ride it bucked several times, and i noticed the theft light flash. Took it back and even for a cobra loaded at 5k i walked away. I talked to ford thought maybe the key. They said some of the units were faulty and would cause this issue, and eventually the theft device would just stop letting the car start.
 

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Cluster diagnostic mode

Try reading the cluster DTC codes for insite into your PATS problem.

http://www.allfordmustangs.com/forums/v6-tech/49159-diagnostic-mode.html

IMO, the bucking is another problem. The typical causes of bucking are:

Excessive EGR flow
Ignition problems
Dirty/bad MAF
Fuel pressure
Dirty/bad MAF
Clogged exhaust
Exhaust leaks before O2 sensor
Base engine problems.
 

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Try reading the cluster DTC codes for insite into your PATS problem.

http://www.allfordmustangs.com/forums/v6-tech/49159-diagnostic-mode.html

IMO, the bucking is another problem. The typical causes of bucking are:

Excessive EGR flow
Ignition problems
Dirty/bad MAF
Fuel pressure
Dirty/bad MAF
Clogged exhaust
Exhaust leaks before O2 sensor
Base engine problems.
Thanks for this link. Really helpful! Reading another thread about bucking here and there, seems that if its a misfire the engine light will flash. so that narrows down the causes. Hope its something simple.
 

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Discussion Starter #8
Yeah I'm gonna be watching my dash now like a hawk. It seems though that when the engine is cold it won't buck or do anything. I drove it all the way to pennsylvania yesterday and back and 5 minutes down the road is when the problem started. At first it bucked a bit and I put it in neutral and the rpms raised over 2 grand. That's why I thought it was maybe a tps or mass air but then it died out and I couldn't get it started cuz the anti theft and when I did it died again and when it started back up I drove it and the anti theft flashed it bucked rele bad then died out. Its weird that it seems to run fine in cooler weather or when the engine is not heated up. After u disarm the theft is the light still suppose to b blinking before u start the car?
 

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Yes the anti theft will flash till the ignition turns on. just a light to show would be thieves your car needs a chip to start.
 

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I'm also using the second key/door opener that came with the car to see if that makes a difference.
FWIIW, the key won't make a difference with regards to PATS and misfire. For the 99-04 PATS, once the car starts, PATS doesn't do anything.

If this were my car, I would inspect the PCM connector for evidence of water damage or rodent activity. Also double check to be sure the PCM ground is clean and corrosion free. The noise from the pcm is likely the sound of relays not being able to latch possibily due to LOW VOLTAGE.
 
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