Keep having Misfire issue.....
- Thread starter zizaspeed
- Start date
Random means any cylinder,... kinda here and there, that's why cell 302 helps to narrow it down to quite possibly the fuel system.
I would use half a bottle of seafoam in the gas and run it through to see what happens. Some injector cleaners recommend being used with every fill-up. It's cheap and easy.
I wash my socks regularly other wise they're pretty rank.
I hope U know the kinda job you might be in for:
http://www.mazdas247.com/forum/showthread.php?123718385-Has-Anyone-Had-Their-Fuel-Pump-Cover-Leak
If it were me I'd use half a can in 1/4 tank of gas and run it till the fuel light comes on.
If it hadn't been done ever before, you could have ten years of lacquer and gum build up. Fuel system cleaners can be bad if they release years worth of buildup all at once. (just like a blood clot or stroke but you've already done it once so you should be fine)
New sock is cheap:
SPECTRA PREMIUM / COOLING DEPOT Part # STR46
* Stocked in outlying warehouse--shipping delayed up to 1 business day
CAD$3.33
AIRTEX Part # FS210 Fuel Strainer
CAD$6.47
DENSO Part # 9520010
OE / OES Replacement Fuel Pump Strainer
CAD$7.74
BOSCH Part # 68021
CAD$8.78
DELPHI Part # FS0194
CAD$10.60
I hope U know the kinda job you might be in for:
http://www.mazdas247.com/forum/showthread.php?123718385-Has-Anyone-Had-Their-Fuel-Pump-Cover-Leak
If it were me I'd use half a can in 1/4 tank of gas and run it till the fuel light comes on.
If it hadn't been done ever before, you could have ten years of lacquer and gum build up. Fuel system cleaners can be bad if they release years worth of buildup all at once. (just like a blood clot or stroke but you've already done it once so you should be fine)
New sock is cheap:
SPECTRA PREMIUM / COOLING DEPOT Part # STR46
* Stocked in outlying warehouse--shipping delayed up to 1 business day
CAD$3.33
AIRTEX Part # FS210 Fuel Strainer
CAD$6.47
DENSO Part # 9520010
OE / OES Replacement Fuel Pump Strainer
CAD$7.74
BOSCH Part # 68021
CAD$8.78
DELPHI Part # FS0194
CAD$10.60
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Installshield 2
Gothenburg Superiority
what do you mean by 'severe idle drop'?...
Technically, rev drop is how the computer 'sees' a misfire...the computer is aware of certain variables (load, intake temp/flow, throttle position, timing, rpm, etc)...if the rpm stutters to a certain threshold WITHOUT these variables being manipulated, the computer calls it a misfire...for a 'random' misfire, the stuttering is usually a drop in revs...for pre-ignition 'knock', it often accelerates the engine (hence the 'lean condition' code for that type of misfire)...but other than that, the computer isn't being as specific as we'd like...its just saying 'something just messed up, and it wasn't me'...
so, not to get off topic, but just an example...i have some custom cams that cause a very lopey idle...this has caused my factory computer to pop a p0300 code pretty often (at least with cold air temps)...even though i'm certain its nothing to worry about, and only happens on cold starts at idle...the engine rpm bounces around enough that computer thinks something is wrong, but the only thing 'wrong' is that a lot of overlap doesn't help idle quality...
but back to your misfire, you have a specific cylinder misfire, right? Its not just p0300?...The computer is seeing more to your random misfire than just rev changes...it has narrowed it down to a specific cylinder (it does this by knowing when a reoccuring misfire is happening, timing wise)...thats why i was saying swap your injectors around, and see if the new codes follow the new locations...if its cylinder specific, its quickly narrowing down the parts it could be, as its not quite as 'random' if that makes sense...and other than valvetrain parts inside the head, the only thing left is a problematic injector...and also, something that is on your side, is that the computer doesn't have codes for 'too rich' iirc...too rich just causes a misfire anyway...too lean, races the engine, and there is a different code for that...so it sounds to me like you have a broken injector that is dripping fuel...unless you have a broken valve or cam lobe...but problems associated with that would be a lot more noticeable i'd imagine...
Yea,... cylinders 1 and 4 are run off the drivers side coil and the passenger side coil runs 2 and 3.
Sometimes brand new coils are bad right out of the box,... and they can test fine on the bench but fail on the car. I remember Hatch kitten had misfire issues and to it to an experienced mechanic who found the problem quickly. It was a faulty wire leading to the coils. It's too bad you can't necessarily rule out a coil issue by putting in new ones.
I think you need to be more of a ghostbuster than a mechanic to chase down a misfire,... or maybe a pile of luck.
Here's a list of potential causes.
okay thanks. This possible cause says fuel quality? hmmmm, maybe I should try chevron more often or high octane? I'm thinking about getting a new MAF since I haven't changed that yet and car is at 124k. I'm going to see if I can get the coilpacks swapped under manuf warranty at autozone.
Maybe before spending all that money on a MAF, you should think about replacing your high pressure fuel filter (fuel pump housing) a lot of people aren't aware that there is a fuel filter inside the plastic fuel pump housing.
I have a new filter to put on (hopefully in the next few days). I have no problems with my car but I'm viewing replacement as a general maintenance item.
If your filter housing isn't leaking, you can much more safely drill out the screw heads if you have to. (just lean in and sniff,... if there is no gas smell, I'm sure you're 97% safe to use a drill). The filter housing isn't too much money and some cars recommend replacing their filter every year. Our cars are 10 years old now and that filter could be pretty full. (I'm gonna cut my old one open and post some pictures of what is inside).
The filter really is something every P5 owner should consider but the job can be a PITA.
Check out this thread for details on the filter replacement. (page 10 post #145 has some awesome pictures)
http://www.mazdas247.com/forum/showthread.php?123718385-Has-Anyone-Had-Their-Fuel-Pump-Cover-Leak
I have a new filter to put on (hopefully in the next few days). I have no problems with my car but I'm viewing replacement as a general maintenance item.
If your filter housing isn't leaking, you can much more safely drill out the screw heads if you have to. (just lean in and sniff,... if there is no gas smell, I'm sure you're 97% safe to use a drill). The filter housing isn't too much money and some cars recommend replacing their filter every year. Our cars are 10 years old now and that filter could be pretty full. (I'm gonna cut my old one open and post some pictures of what is inside).
The filter really is something every P5 owner should consider but the job can be a PITA.
Check out this thread for details on the filter replacement. (page 10 post #145 has some awesome pictures)
http://www.mazdas247.com/forum/showthread.php?123718385-Has-Anyone-Had-Their-Fuel-Pump-Cover-Leak
I got my filter in. I posted lots of pictures. I cut open my old fuel filter (fuel pump housing) and there was all kinds of fine black crap inside,... I'm sure it can plug up enough to cause a drop in fuel pressure and even cause a misfire. I didn't replace or even clean the sock,.. it's really just a strainer and doesn't really plug up.
Every other car I know of say's to replace the fuel filter within two years.
http://www.mazdas247.com/forum/show...How-To-Change-Your-Fuel-Filter-(lots-of-pics)
Every other car I know of say's to replace the fuel filter within two years.
http://www.mazdas247.com/forum/show...How-To-Change-Your-Fuel-Filter-(lots-of-pics)
whatusername
Member
- :
- 02 protege5
running a fuel injector cleaner every other time u pump will foul the plugs... time for new plugs
If I were you,... I would consider replacing the coil pack again. I know yours are new but they have been the source of problems for many people trying to chase down a misfire problem. Coils can test fine on the bench but fail on the car and have been known to be bad right out of the box. There has been three different people here on the forums in recent months trying to chase down a misfire and it turned out to be coil packs. One lady still had her old coils and put them on and so far,... it appears to have fixed her problem.
They are relatively cheap (compared to a MAF anyway) and take two minutes to install.
Unfortunately,... putting in new coils doesn't mean you can rule them out as a source of problems and they seem to misfire at random, intermittent times,... accept they do seem to start malfunctioning after they get hot.
They are relatively cheap (compared to a MAF anyway) and take two minutes to install.
Unfortunately,... putting in new coils doesn't mean you can rule them out as a source of problems and they seem to misfire at random, intermittent times,... accept they do seem to start malfunctioning after they get hot.
exchanged them, cleared code, came back today. gonna check code on tuesday, i'm still waiting for my MAF, if that doesn't solve it then I'm moving injectors around, and possibly do the fuel thing.
On a side note, today when I got out of my car I noticed my engine and that it's super loud, seems to be more than normal. Maybe valves?
On a side note, today when I got out of my car I noticed my engine and that it's super loud, seems to be more than normal. Maybe valves?
So got new MAF in, didn't fix the issue. p0300, story of my life. So just ordered the fuel sock, fuel housing, and the other peice that pcb recommended, gonna try that at the end of the week.
On a side note, does anyone know what the resistance of our spark plug wires should be? I measured mine, the short one is about 900 ohms, and the longer is closer to 1kohm. Seems like good wires are suppose to be 25-50 ohms per foot?
On a side note, does anyone know what the resistance of our spark plug wires should be? I measured mine, the short one is about 900 ohms, and the longer is closer to 1kohm. Seems like good wires are suppose to be 25-50 ohms per foot?
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