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Misfire problem diagnosed!
- Thread starter grindMARC
- Start date
The dealer called this afternoon and my misfire problem has them completely stumped. I spent about 20 mins on the phone with the tech. He said fuel pressure looks good. Compression is perfect. He spent the whole day on the car and can't figure it out. His best theory at this point is a kooky electrical issue where something got cut or damaged. Or possibly an exhaust valve sticking open. But before he chased down any of these theories he was going to call some national tech support line and talk to them.
BTW, he said that if there was any sort of obstruction in the return fuel line, a CEL would get kicked out indicating an over-pressurized fuel system.
BTW, he said that if there was any sort of obstruction in the return fuel line, a CEL would get kicked out indicating an over-pressurized fuel system.
Did it run better afterwards?
The 8 screws that hold the pump in are 4mm. I stripped 4 out of 8, so I went to the hardware store and switched them all out to bolts.
I think it takes longer to get the fuel lines unhooked then anything.
The fuel lines were a joke. It took less time to get those off than unplugging the connector. I put a precision screwdriver under the back side, pushed it, then pulle the line right off. It seems to be running better. I will give it a few days to settle itself in and see if the issue returns. I will post up any updates. We stock bolts here so I was lucky. Mine were rusted and mangled beyond reuse.
Issue has returned. Car has a hard studder/misfire, car has no power when in throttle, meaning I try to go faster and the car actually slows down becuase it's missing so hard. Lasts for about 10 seconds or so, sometimes less. Then clears up. Current changes/repairs to try and fix issue include New EGR, O2's, Fuel strainer, fresh plugs, seafoam engine oil/gas/intake, air filter. Could this be a coil pack issue?
Issue has returned. Car has a hard studder/misfire, car has no power when in throttle, meaning I try to go faster and the car actually slows down becuase it's missing so hard. Lasts for about 10 seconds or so, sometimes less. Then clears up. Current changes/repairs to try and fix issue include New EGR, O2's, Fuel strainer, fresh plugs, seafoam engine oil/gas/intake, air filter. Could this be a coil pack issue?
My problem sounds very similar, but the hesitations and misfires happen constantly now. Yesterday, the mazda tech called and said their best guess was the MAF -- despite the fact that it tests "good." They'll put it on tomorrow and call me.
Tifun, if you can mange it, ask someone near you with a p5 to swap MAFs for a few mins! Its such a simple thing to swap out (swap the entire airbox lid), its almost silly to take a $250 chance. But like me you're into this problem for a bunch of $ and parts already!!
Our hesitation was happening a lot. Atleast once every drive. Now since the strainer change it has only happened once. I do feel it's fuel system related. Maybe a sign for the pump or a week fuel cap. Or the injectors need flushed. I've ran the mac and it's showing appropriate volts so I'm personally ruling that out.My problem sounds very similar, but the hesitations and misfires happen constantly now. Yesterday, the mazda tech called and said their best guess was the MAF -- despite the fact that it tests "good." They'll put it on tomorrow and call me.
Tifun, if you can mange it, ask someone near you with a p5 to swap MAFs for a few mins! Its such a simple thing to swap out (swap the entire airbox lid), its almost silly to take a $250 chance. But like me you're into this problem for a bunch of $ and parts already!!
Issue has returned. Car has a hard studder/misfire, car has no power when in throttle, meaning I try to go faster and the car actually slows down becuase it's missing so hard. Lasts for about 10 seconds or so, sometimes less. Then clears up. Current changes/repairs to try and fix issue include New EGR, O2's, Fuel strainer, fresh plugs, seafoam engine oil/gas/intake, air filter. Could this be a coil pack issue?
What code are you getting?
patsissons
Member
- :
- 2003 P5
Just got a P0300 (Random Misfire Detected) again the other night, so i hooked up my new odb2 reader to grab the freeze frame data. This obviously won't help me, but maybe those who are more mechanically involved with their mp5's might find some use out of this data. I will also pass this onto the mazda dealership mechs soon to see what they make of it.
I created a google spreadsheet with the data i collected entered into the spreadsheet. I will continue to add new data as i receive P0300's. Please feel free to add your own freeze frame data to the spreadsheet (if you have access to freeze frame data). You can access this freeze frame spreadsheet at the following url:
http://spreadsheets.google.com/ccc?key=pjgVyIX-40-XqQatP2g9fTQ
I created a google spreadsheet with the data i collected entered into the spreadsheet. I will continue to add new data as i receive P0300's. Please feel free to add your own freeze frame data to the spreadsheet (if you have access to freeze frame data). You can access this freeze frame spreadsheet at the following url:
http://spreadsheets.google.com/ccc?key=pjgVyIX-40-XqQatP2g9fTQ
sprinter119
Member
- :
- 2013 Mazdaspeed3
sub
and the strainer is not the only filter on the car! read the faq and you will see!
How do you gain access to the high pressure filter? I had the pump assembly out and couldn't figure out how to actually get to it. Plus there isn't a replacement.
and the strainer is not the only filter on the car! read the faq and you will see!
The high-pressure filter does not have an element.
The only serviceable item in that filter is a little black rubber o-ring that comes with a replacement fuel pump -- but that's it.
Clean the throttle body and the EGR valve.
EGR is brand new. The throttle body has been cleaned as well. Those were some of the first things I tried in hopes to fix my issue. I've done a complete tune up on the vehicle. The only thing left is the small filter you describe. I guess I should just go buy a new pump and redo it. I'm at a complete loss as to what else to do.
holy s***, didn't I say to read the faq?
don't argue with me until you know wtf you're talking about
wtf are you talking about? you still haven't read the faq yet
buy ONLY what is shown on there and nothing more
Stop being an ass. You didn't post a link and if you are meaning http://protege5.ugly.net/ it doesn't work.
X2Stop being an ass.
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