Old School Ford Taurus With Dead Misfire Takes An Interesting Turn! 

Hard to beat a good mystery. 👍

I agree !

5 Years in and I still feel like im learning this way

Ah that could be 🧐🤔

I can confirm this is the case with my autel working on late 90s early 2000s porsches you see a lot more live data in generic obd2 vs the manufacturer specific selection

@@Xander-H excellent advice thanks

There will be times where tests for certain modules are not shown in the module itself. You may need to back out to the service options or hot functions.

Good point. but why the computer doesn't through a code for the injector?

I guess as Mr Sherwood is saying, the ecu does see some sort of resistance, and it is not like a dead short or open circuit, so it almost tries to auto correct these funny measurements and by doing so every 30 sec there will be a mis fire condition. I think the software engineer figured if he programs a mis fire on that particular faulty cylinder the technician will eventually get to the conclusion that there is a fault by comparing resistance values of different injector coils.

​@@johanbotha9889If that is the case then there could still be some bad wiring, and with the plug disconnected the ECU should detect a circuit open. If there is still resistance with the plug out, then it could mean a corroded harness.

@@Stoney3K Correct, but remember Mr Sherwood couldn't understand why the problem persist while he used his test lamp and injector tester. The ecu is programmed to give a code of mis fire when an open circuit or short occurs. Those ecu's are not as precise as the modern cars because of memory chips and advanced technology and it does detect a problem, the only difference is the programmer didn't physically put a code with the wording of open circuit or short circuit. As I say you need a lot of memory to write a certain language and I think the technology limited him so the best way to assist the technician is by simply saying mis fire on the given injector the fault is on.

@@johanbotha9889 Thanks for your time. I agree with you the old PCM's not as precise as the new PCM's

injector Coil was open.

Has search bar

I was wondering about that, because my cheap generic code reader can do live misfire counts.

That would have been my first strategy instead of scratching my head and scoping for an hour. Swap injectors 4 and 5. If the miss moves you are certain the injector is bad. 10 minutes of diagnostic time.

If it is specific to bank 2 it is not a fuel issue. That would affect both banks. If it is setting the code at idle it will most likely be a vacuum leak. If that “well reviewed “ mechanic is giving you a list of parts to throw at it, he is clueless. With the money you have already wasted on probably unreliable aftermarket parts, you could have purchased a relatively inexpensive scan tool ,which is a must for diagnostics. Code readers are useless for diagnostics. You either have a bad intake gasket, bad injector or coil, or a false reporting upstream bank 2 O2 sensor.

@@brianw8963 Thanks for responding. I have a cheap scan tool/code reader, as mentioned in my comment. I checked the codes again last night and I'm getting P0171 Bank 2 lean in current DTCs, and P0174 bank 2 lean code in the pending DTCs. I also have P0193, fuel rail pressure sensor circuit high, in pending DTCs, but that may be from when I unplugged the fuel rail pressure sensor while troubleshooting. It's was the first time that code popped up, and I've scanned and erased codes over a dozen times. I bought a Motorcraft PCV valve and MAF sensor. The new fuel filter is a Wix, the one I took off was two years old and had no sediment in it. The fuel pump was replaced 2 years ago with a Bosch unit, along with the filter. I usually change the fuel filters when I service the transmission every two years. I found one vacuum leak and fixed it before I took it to the mechanic, no change. The mechanic couldn't find any other vacuum leaks. No misfire codes, and it runs relatively smooth. It just acts like it's not getting enough fuel. I'm beginning to suspect the fuel pump, or the unit that controls it. I guess I could switch the oxygen sensors to see if the code moves. I just bought a sensor socket, so I guess I need to use it.

@@genericsomething does your scanner show fuel trims and O2 data? As I mentioned, if you had a low fuel pressure problem, both banks would be lean. This is a v-6 correct?

@@brianw8963 Yes, I can read live data. The long term fuel trims are high, and remain that way, on both banks (yes, it's a V6). The upstream O2 sensors look normal. I've been messing with this thing for a month. It keeps acting like it's just not getting enough fuel. The fuel pressure remains in spec while running, it just seems like the volume isn't enough. I'm trying to figure out how to measure the flow and volume on a returnless system with no Schrader valve on the fuel rail.

@@genericsomething Are both O2 sensors reporting lean? If fuel pressure is good there should not be a flow or volume issue, but to satisfy your curiosity, just disconnect the fuel line somewhere, perhaps at the fuel rail and hook a hose to it and put the end of the hose into a bucket or some bottle or something. Turn the key on and see what happens. If You can get a good tight fit on the line you could even hook a pressure gauge up to verify the pressure. Kinda odd that it only has code for bank 2 , if that is the case. Interesting.

The injector is open, so what would going on the backside prove?

@@mikesabin8568 He kept losing control on the injector side of the connector, I just meant to check on the back side of the connector toward ECM.

No, we replaced the evaporator core in it.😃

Topdon for the win!

It was a dead miss so I didn't feel the need for KOEO or KOER. I'm all about looking at Description and Operation. After working on this vehicle I looked in SI and couldn't find anything saying the PCM will shut down injector. If you find something please let me know so I can know where to look next time.

Ok