03 grand caravan w/ 3.3L P0203 code Need Help!

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Aug 25, 2012 | 07:55 PM
  #1  
I have read over this forum and know there were a few post about this and I have tried everything I could to fix it but I am still getting this code and there is still a Misfire . Here is what I have done so far :
Changed Injector
Changed Spare plugs & Wires
Checked all of the the injector wires for continuity ( from harness and to the computer as I had read there were a lot of problems there)
Tried the TPS but when I Changed it I could not get the engine to start and it was the only one my parts store had in stock (they said this was the second one that they heard of this happening to) I got a code P0123 when I had the new one in.

I was wondering if it could be another cylinder that was misfiring but when I put the old injector in it ran worst so I am really thinking that injector was bad.

ANY Other ideas would be great .... I am stumped and really need this to be running and can't keep buying parts that don't fix it as money is real tight.

Thanks for all your help
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Aug 25, 2012 | 08:16 PM
  #2  
This may be basic, but I want to make sure you understand how the system works. Power is supplied to ALL the injectors from the auto shutdown relay on the brown/white wire. The PCM doesn't provide power, it supplies GROUND. So the PCM pulses the ground to fire the injector.

These vehicles are known for bad wiring. So some shops have had to run new wires. You say you did continuity check, but you didn't test the wires under load. This may sound stupid, but it you feel like humoring yourself, splice a new wire into the brown/light blue at inj #3 and run it all the way to the PCM and splice it in there. If that works, you know it's a wiring problem.
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Aug 25, 2012 | 11:45 PM
  #3  
Quote: These vehicles are known for bad wiring. So some shops have had to run new wires. You say you did continuity check, but you didn't test the wires under load. This may sound stupid, but it you feel like humoring yourself, splice a new wire into the brown/light blue at inj #3 and run it all the way to the PCM and splice it in there. If that works, you know it's a wiring problem.
Thanks Rick, I tried but still getting error code P0203 and you can feel it misfiring, I am willing to try anything If anyone else has any ideas....
I do have another question is it possible that it could be misfiring on another cylinder?? not Cylinder 3 ?
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Aug 26, 2012 | 03:47 PM
  #4  
Okay another step down... still no change
I did a compression test on the cylinder and it matched up with all of the others so I know it is not that... How ever When I pulled the new spark plugs out I noticed the 2/4/6 were dirty yet the #3 was clean and did not look like it had fired , So I took and old plug and put it in the #3 wire and turned the motor over to see if it would spark and it did... Still no Clue but it seems as if I may not be getting fuel to that cylinder ... I replaced the injector with an after market injector from BWD and it seems to be different the port that goes into the fuel rail is about 2 times the size of the factory one, is that common?

I am running out of ideas, no check that I have run out of ideas... Any help would be great.
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Aug 26, 2012 | 04:16 PM
  #5  
Either feel the injector or touch a screw driver to it holding the handle to your ear. Can you feel or hear it click? Another way is to connect a noid light at the injector connector. If you can't feel, hear it or see that the noid light isn't flickering and you are sure the wiring is good change the PCM.

One example of a noid light:
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Aug 27, 2012 | 12:22 AM
  #6  
This sounds like the injector harness and the PCM driver. Don't ohm test the wire harness, open it up and inspect for any melted wires. It will only cost a roll of tape if all the wires are fine.
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Aug 27, 2012 | 06:25 PM
  #7  
Not looking good for the PCM
Okay I have done -
Checked injector wire harness (opened it all up, plus ohm tested)
Replaced Injector
switched injectors around to see if I would get a different code (misfire in dif, cylinder)
changed wires and plugs ...
ran jump wire right to PCM from the #3 injector
now I just did a Noid Light test and No Light
Any Other ideas or am I out of other options and will have to try the PCM
Is there any other way to check the PCM driver to see if it is that or something else that I am missing

Thanks again too everyone who tried to help me out.
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Aug 27, 2012 | 07:12 PM
  #8  
"Is there any other way to check the PCM driver to see if it is that or something else that I am missing"

Not that I'm aware of except maybe a wire harness shake test close to the connectors. This may reveal a spread female contact on the connector. Injector doesn't click, noid light doesn't flash, continuity of driver wire checks good, change the PCM.
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Sep 10, 2013 | 10:42 PM
  #9  
Getting the same code, engie running rough, and sinks as if there is a fuel leak. This is a long list of things Senuff did,, that allot of $$$.

Where should I start? With the new lead test from the injector on cylinder 3 to the PCM? Help please!!
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