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Discussion Starter #1 (Edited)
So i bought a Ford Taurus 2007, 168,000 miles. Replaced MAF. Smelled of gas at first, ran crc treatment to the intake, then followed it up with seafoam intake cleaner next day. This did not resolve but made the car run a bit smoother. Went through the coil pack unplugging one by one, discovered a coil not firing. replaced the coil pack and spark plugs (they were pretty fouled), this made it run smoother. Then because of the o2 sensor code, i replaced bank 2 sensor 1, and same code persisted. I bought a live data code scanner, apparently the volt is stuck at 0.01. So tomorrow I will probe it and send some power to it and see if it shows volt to the live data, if not then its a bad harness. I also replaced the fuel filter. I also get intermittent check charging system, then i notice the erratic idle happens a lot of times right at that point and usually stalls. Checked charging from alternator and drop test, all within spec. I have also smoke tested it and the only viable smoke was from the EGR. I also sucked on the tube that connects to the EGR nipple and verified it was working as it stalled the car. I do have a pending cam sensor code, I do not have any chirping the cam synchronizer. I also took out the IAC and cleaned it, and replaced it with a new gasket. I am attaching a video from the live data, maybe someone will find it useful to help me figure this problem out. So any input would be nice. Thanks in advance.
 

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A couple things are probably going on here. For starters, the car is running pretty rich, as you could already tell. Likely due to the bank 1 sensor 2 output being stuck lean. The computer uses the upstream sensor to assess the mixture and set the trims, so no surprise there that it's trending rich. Second, what was your voltage reading at the battery with every accessory turned on? The car is showing in the 11V range which would indicate a bad alt or corroded charging wire. And third, just because the camshaft synchronizer isn't squeaking doesn't mean it doesn't need replacement. They can wobble and shave the sensor down and give erratic readings to the computer. I would definitely suspect some electrical issues going on here. How old is the battery?
 

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Discussion Starter #4 (Edited)
A couple things are probably going on here. For starters, the car is running pretty rich, as you could already tell. Likely due to the bank 1 sensor 2 output being stuck lean. The computer uses the upstream sensor to assess the mixture and set the trims, so no surprise there that it's trending rich. Second, what was your voltage reading at the battery with every accessory turned on? The car is showing in the 11V range which would indicate a bad alt or corroded charging wire. And third, just because the camshaft synchronizer isn't squeaking doesn't mean it doesn't need replacement. They can wobble and shave the sensor down and give erratic readings to the computer. I would definitely suspect some electrical issues going on here. How old is the battery?
Camshaft sensor times the fuel injection so fuel may not be injecting into open intake valves.


I actually had a camshaft sensor go bad with out it being the mechanical synchronizer.
No clue on the battery, came with the car, but advanceauto and walmart it checked out as a good battery, like 800 cold cracking amps. Checked battery was 12.2 before start, after start it remained around 14.5. checked ohm of the camsensor, its around 500 resistance, spec is 250-1000 from reading. Have not unplugged the o2 sensor as i dont feel like crawling under the car its about 25F outside lol and not including the windchill.
Thanks for the input its appreciated, any further ideas?

 

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Discussion Starter #6
Resistance is not a goog measure for the sensor. Believe it is a Hall Effects semi conductor that is activated by the metal tooth on the mechanical drive.
Thanks, I plan to take off the sensor tomorrow, i found a good youtube video reference, but mainly will be looking for scratches on the sensor or play in the synchronizer itself. Think that's a fair assesment?
 

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2 types of sensors used over the years. Hall switch (3 wire) sensor or VR sensor (2 wire) Hall switch can not be tested with ohmmeter. Ohms will give you limited info (open or shorted) on the health of a VR (Variable Reluctance) sensor.
 

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Seems logical but it doesn't account for a failed or noisy sensor. Didn't think they were that expensive to just replace. With the headache they are to reach because of the wiring harness, I would switch it out. Have you had a chirping sound coming from that area?
 

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Discussion Starter #9
Seems logical but it doesn't account for a failed or noisy sensor. Didn't think they were that expensive to just replace. With the headache they are to reach because of the wiring harness, I would switch it out. Have you had a chirping sound coming from that area?
2 types of sensors used over the years. Hall switch (3 wire) sensor or VR sensor (2 wire) Hall switch can not be tested with ohmmeter. Ohms will give you limited info (open or shorted) on the health of a VR (Variable Reluctance) sensor.
Thanks for the information. I unplugged the cam sensor and started the vehicle, I seen no difference in behavior with or without it plugged in. Am going to check the key on volts at the harness, from reading the service manual, says it should be 1 volt, if less then you have a short. Do you think its necessary to unplug the pcm to perform this test?
 

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Discussion Starter #10
Thanks for the information. I unplugged the cam sensor and started the vehicle, I seen no difference in behavior with or without it plugged in. Am going to check the key on volts at the harness, from reading the service manual, says it should be 1 volt, if less then you have a short. Do you think its necessary to unplug the pcm to perform this test?
Ok tested both to battery negative both have .3 to .4v with key on and fluctuates between that with car running... So open circuit it seems?
 

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go to autoservicecosts.com ......click on my car...and then click on Obd2 codes it will tell you what the code is and the symptoms,also it will tell you what to check or fix.
 

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Discussion Starter #12
Had the car alternator load tested at advanced auto 3 times, it failed the third time. So i pulled the alternator, and had them test it at advanceauto, it passed lol. Went to napa and bought a refurbished, car runs 200 percent better, still stalls a few times until it reaches temp, after that runs fine. Only problem now is the battery light is on and still hitting me with check charging system, I replaced the battery, and its still there, any ideas?? Note I had advanceauto check it under load again and it passed.
 

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Discussion Starter #13
Bump, and to add the speedometer goes crazy at times, and bad shifting starting happening. Dont have the money to put this thing in the shop... I did notice speedometer working correctly while driving then hit a bump and it went crazy again. I checked all ground wires and the resistance is under 2ohms. I do have a .68 amp pull with computer sleeping, , 1.2amp pull with computer engaged going to try and check by pulling fuses one by one. rebuilt alternator making a ticking noise after install also, will be taking back to napa for exchange tomorrow morning. I would really like some help, if someone can point me in the right direction??
 

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Bump, and to add the speedometer goes crazy at times, and bad shifting starting happening. Dont have the money to put this thing in the shop... I did notice speedometer working correctly while driving then hit a bump and it went crazy again. I checked all ground wires and the resistance is under 2ohms. I do have a .68 amp pull with computer sleeping, , 1.2amp pull with computer engaged going to try and check by pulling fuses one by one. rebuilt alternator making a ticking noise after install also, will be taking back to napa for exchange tomorrow morning. I would really like some help, if someone can point me in the right direction??

Alt is likely bad or: BIG OR: if you use a '01 Alt as example on '02 or later you will get a delayed red light with actual volts charging of ~13.8V. Starting '02 and later the Alt uses a different regulator and the difference is not visible but the results are. Starting '02 the system uses the center wire in the connector to let the PCM adjust the charging rate.


2 ohms is way to much on ground but do not know how you would be testing. Leakage current is way too high also.


-chart-
 

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Discussion Starter #15
Alt is likely bad or: BIG OR: if you use a '01 Alt as example on '02 or later you will get a delayed red light with actual volts charging of ~13.8V. Starting '02 and later the Alt uses a different regulator and the difference is not visible but the results are. Starting '02 the system uses the center wire in the connector to let the PCM adjust the charging rate.


2 ohms is way to much on ground but do not know how you would be testing. Leakage current is way too high also.


-chart-
THANK YOU!
Oh wow at idle it was going around 13.8, and only really fluctuates up if i rev the engine. So your telling me napa is selling me the wrong alt or has wrong voltage regulator?
here is the link to the one they sold me https://www.napaonline.com/en/p/RSE2133204F
 

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THANK YOU!
Oh wow at idle it was going around 13.8, and only really fluctuates up if i rev the engine. So your telling me napa is selling me the wrong alt or has wrong voltage regulator?
here is the link to the one they sold me https://www.napaonline.com/en/p/RSE2133204F
Most important ground when Alt is charging is shown. See pic. Note arrows, the large eyelet is the ground from the engine/Alt to the cowl common post where most of the power negative is sourced. In the pic, note bolted over painted metal. And in the pic the PCM ground is also attached. I cleaned this up and fixed a case of irregular ide speed.


Alt '00-'01 use a "soft start" regulator. '02-'07 used the PCM managed regulator. It can be mis labeled. Ford uses color coded regulators to identify. Aftermarket can be anything. I put an '01 Alt on '03 so learned the hard way. Others can chime in with same issue. In my case the red light came on about 10 seconds after starting up.


-chart-
 

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Discussion Starter #17 (Edited)
Most important ground when Alt is charging is shown. See pic. Note arrows, the large eyelet is the ground from the engine/Alt to the cowl common post where most of the power negative is sourced. In the pic, note bolted over painted metal. And in the pic the PCM ground is also attached. I cleaned this up and fixed a case of irregular ide speed.


Alt '00-'01 use a "soft start" regulator. '02-'07 used the PCM managed regulator. It can be mis labeled. Ford uses color coded regulators to identify. Aftermarket can be anything. I put an '01 Alt on '03 so learned the hard way. Others can chime in with same issue. In my case the red light came on about 10 seconds after starting up.


-chart-
Thanks for the help, i had already went through each and every ground and sanded it to bare metal and cleaned each connector, applied electric grease and rebolted them down. As for the alternator, from reading further it has a internal regulator, and so does ever other aftermarket i see online. Does that mean the pcm has no control over the alternator voltage and if so check charging system and battery light? I am also considering the fact i have a short in my wiring harness somewhere... I do see some deterioration of certain parts of the harness, and where the previous owner has operated on it.
 

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Thanks for the help, i had already went through each and every ground and sanded it to bare metal and cleaned each connector, applied electric grease and rebolted them down. As for the alternator, from reading further it has a internal regulator, and so does ever other aftermarket i see online. Does that mean the pcm has no control over the alternator voltage and if so check charging system and battery light? I am also considering the fact i have a short in my wiring harness somewhere... I do see some deterioration of certain parts of the harness, and where the previous owner has operated on it.
Ford has used "internal" regulators for many years. See pic. This is for the DOHC and also used on Ford V-8 vehicles. Vulcans use a different one but same issue. The three regs in the pic will bolt on the Alt but they are quite different and do not work in the wrong application. They are identified by color. Many cases of the wrong one being on replacement Alt. PCM cars ('02 and later) use the white one. Color code is for Ford parts, aftermarket may use different colors like blue, green, or orange.


My experience with the wrong Alt on a PCM car is: Light off for about 10 seconds after starting and then light always on. Charging volts 13.8. With correct Alt will charge 14.4-15.0 on startup then taper off after some driving, depending on the outside temperature.


As a sidebar: my Buick has the regulator on the firewall in what they call the body control module. Put in a cool low vibration place.


-chart-
 

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^^^^^+1 on the low charging volts. My 2006 charges at 14.5 volts plus at idle. Don't trust those parts store tests. This was my experience. https://www.taurusclub.com/forum/82-maintenance-repair/218682-how-good-parts-store-alternator-test.html
You could have the slip rings 99.9% worn out and it passes. The Alt can turn up to 18,000 rpm but the test is only low speed. I have had 2 sudden regulator fails and one overcharging.


I only use NEW replacements.


-chart-
 
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