Hello all I really need some help. Two weeks ago out of the blue my girlfriends Mazda Protoge5 started running like crap. I took it up to the parts store and read the code which was a P0303 a cylinder 3 misfire. Same thing happened to her last year so she had it in the shop and had new plugs wires and a fuel injector put on number 3 cylinder. To top it off the Bastards charged her 800.00 for the work that maybe took a half hour tops.....Regardless it seemed to fix the problem.
This time when it started again I did the work. I pulled the number 3 plug which had proper looking burn to it but replaced it anyways. I also went and picked up a new coil pack. Put the pack on and no change. Also swapped it around with the other pack a and still no change. checked all connections and also sprayed with electronic cleaner. Still not a fix. I ordered a new fuel injector from rock auto for 26 bucks since all the local stores wanted over 200. I put that on that night and thought it seemed to fix the issue. It felt like it ran okay to me, but the next day my girlfriend drove it and complained it was running like s*** again. WTF???? Seemed to run fine the night before but maybe I did not drive it long enough or let it warm up enough.
Again I went under the hood...I heard a hissing sound which sounded like leaking air coming from the fuel rail dampener. I had no experience with that part but spent the 100 and replaced it anyways. Still no change. I called the dealer and spoke to a mechanic. I explained all I had done so far and also the hissing sound which he said was likely a bad intake gasket near the dampener caused by a malfunctioned fuel pressure regulator leaking gas into the manifold. With his recommendation I then set into doing the real work on it. I pulled the intake manifold thanks to some instructional help on the forums. I replaced both the upper and lower gaskets. I pulled the ERG valve cleaned and checked that the plunger was functional. I mounted it with a new gasket along with a new gasket on the throttle body. After assembling I thought I might be in the clear. I started her up and the misfire was still there, but the hissing sound was gone so it was not a total waste.
Now i am going bonkers...
Here are some things to note....during the fix I broke the VSV EGR vacuum solenoid. ( by the way a little brittle piece of junk) Which I have not replaced yet. Also I have not replaced the fuel pressure regulator. I have not done either yet because after checking a clearing the code it came back as a cylinder 3 misfire again. I would think if either of the parts where bad and needed replaced they would cause a general misfire code not one related to a specific cylinder. Also I changed and checked the oil and coolant, it is not a head gasket issue. What am I missing here that I may have not determined yet? One thing I am thinking is that maybe I received a defective Fuel injector so I am going to request a replacement. other than that I am at a loss.... Please Help!!!
Joe
This time when it started again I did the work. I pulled the number 3 plug which had proper looking burn to it but replaced it anyways. I also went and picked up a new coil pack. Put the pack on and no change. Also swapped it around with the other pack a and still no change. checked all connections and also sprayed with electronic cleaner. Still not a fix. I ordered a new fuel injector from rock auto for 26 bucks since all the local stores wanted over 200. I put that on that night and thought it seemed to fix the issue. It felt like it ran okay to me, but the next day my girlfriend drove it and complained it was running like s*** again. WTF???? Seemed to run fine the night before but maybe I did not drive it long enough or let it warm up enough.
Again I went under the hood...I heard a hissing sound which sounded like leaking air coming from the fuel rail dampener. I had no experience with that part but spent the 100 and replaced it anyways. Still no change. I called the dealer and spoke to a mechanic. I explained all I had done so far and also the hissing sound which he said was likely a bad intake gasket near the dampener caused by a malfunctioned fuel pressure regulator leaking gas into the manifold. With his recommendation I then set into doing the real work on it. I pulled the intake manifold thanks to some instructional help on the forums. I replaced both the upper and lower gaskets. I pulled the ERG valve cleaned and checked that the plunger was functional. I mounted it with a new gasket along with a new gasket on the throttle body. After assembling I thought I might be in the clear. I started her up and the misfire was still there, but the hissing sound was gone so it was not a total waste.
Now i am going bonkers...
Here are some things to note....during the fix I broke the VSV EGR vacuum solenoid. ( by the way a little brittle piece of junk) Which I have not replaced yet. Also I have not replaced the fuel pressure regulator. I have not done either yet because after checking a clearing the code it came back as a cylinder 3 misfire again. I would think if either of the parts where bad and needed replaced they would cause a general misfire code not one related to a specific cylinder. Also I changed and checked the oil and coolant, it is not a head gasket issue. What am I missing here that I may have not determined yet? One thing I am thinking is that maybe I received a defective Fuel injector so I am going to request a replacement. other than that I am at a loss.... Please Help!!!
Joe
