misfire flashing CEL problem

[hedlesschkn]

okay, i have been searching through the forums for several hours on several different occasions so i have decided to post a direct help to my specific problem since my situation doesn't seem to quite relate exactly to some of the other posts.

the story:
bought my car with 75k on it, drove it for a week and it started misfiring on the highway, i pulled over let it sit it started right back up not problems, cel turned itself off shortly after. several days later i start my car, drive for a while turn it off, go to start it up again while warm and it misfires like crazy sputtering jerking flashing CEL. let it cool down, start it up and it runs fine so i drive her to autozone and get the code read p0300, random misfire. searched the forum and did a few suggested things (see below) i ended up cleaning the EGR valve and oiled it with wd40, seemed to do miracles to my car, ran better than before, idled more stable, better response, etc. could not get the car to misfire at this point. (tried starting it cold and warm, starting the engine via turning the car off while moving and then letting back off the clutch) car ran fantastic. i just drove 500 miles to school, and then drove the car for another few days up here with no problems. today it starts misfiring again. my dad suggests cleaning the egr valve again and using something better than wd40 to lube it so i do (used brake-kleen as suggested to clean and 3in1 oil to lube as suggested in the how to). car runs amazing again, i drive maybe a half mile, go to a meeting on campus for an hour or so, go back out to my car and it misfires again when i try to start it. so now ladies and gents, i am here begging for you help to solve this issue once and for all.

things tried:
-pulled the fuel pump made sure the fuel sock was clean (looked clean but i cleaned it more anyways)
-pulled the spark plugs, checked for corrosion, spacing, and burn marks they look almost new.
-checked the resistance on the plug wires according to the user manual, seems fine
-cleaned the EGR valve... twice

commonly asked:
"is there smoke" - not that i notice
"does it knock or ping, any metallic noises" - no just misfiring and studdering / shaking
"did you replace the coils" - not yet, wanted to confirm that it could be the coils even though sometimes it runs fine and other times it does not.
"cracks in the hose that goes into your block from the intake" - looks crack free, note: i have an aftermarket cold air intake

any help would be greatly appreciated, thank you all in advance!

 

[junya1985]

ok well coils arent that bad and if they haven't been done i would suggest doing them i know you have a protege 5 but same coils as a msp and my car has been through quite a bit of coils so thats my first suggestion also you yes cleanin the egr with brake kleen or even something strong like carb or throttle body cleaner will work using a little brush also check the boots to the coils make sure there not cracked and arcin

 

[slavrenz]

okay, i have been searching through the forums for several hours on several different occasions so i have decided to post a direct help to my specific problem since my situation doesn't seem to quite relate exactly to some of the other posts.

the story:
bought my car with 75k on it, drove it for a week and it started misfiring on the highway, i pulled over let it sit it started right back up not problems, cel turned itself off shortly after. several days later i start my car, drive for a while turn it off, go to start it up again while warm and it misfires like crazy sputtering jerking flashing CEL. let it cool down, start it up and it runs fine so i drive her to autozone and get the code read p0300, random misfire. searched the forum and did a few suggested things (see below) i ended up cleaning the EGR valve and oiled it with wd40, seemed to do miracles to my car, ran better than before, idled more stable, better response, etc. could not get the car to misfire at this point. (tried starting it cold and warm, starting the engine via turning the car off while moving and then letting back off the clutch) car ran fantastic. i just drove 500 miles to school, and then drove the car for another few days up here with no problems. today it starts misfiring again. my dad suggests cleaning the egr valve again and using something better than wd40 to lube it so i do (used brake-kleen as suggested to clean and 3in1 oil to lube as suggested in the how to). car runs amazing again, i drive maybe a half mile, go to a meeting on campus for an hour or so, go back out to my car and it misfires again when i try to start it. so now ladies and gents, i am here begging for you help to solve this issue once and for all.

things tried:
-pulled the fuel pump made sure the fuel sock was clean (looked clean but i cleaned it more anyways)
-pulled the spark plugs, checked for corrosion, spacing, and burn marks they look almost new.
-checked the resistance on the plug wires according to the user manual, seems fine
-cleaned the EGR valve... twice

commonly asked:
"is there smoke" - not that i notice
"does it knock or ping, any metallic noises" - no just misfiring and studdering / shaking
"did you replace the coils" - not yet, wanted to confirm that it could be the coils even though sometimes it runs fine and other times it does not.
"cracks in the hose that goes into your block from the intake" - looks crack free, note: i have an aftermarket cold air intake

any help would be greatly appreciated, thank you all in advance!

Dying coils will work intermittently, but one day they're just gonna die. Replace these and your problems should be over. There's a slim chance it's your plug wires, so you may want to replace those as good measure (I usually go 100k mile intervals, but 75k miles isn't too bad to replace them).

 

[P-Funk!]

Yeah - one more for the coils. After you clean the EGR one more time - becasue if that fixes it AGAIN you need to just replace it wtih a new one (improved design).

The reason we keep coming back to the EGR is that we run so rich at WOT and it will coke up the intake system...

 

[hedlesschkn]

okay guys, thank you very much. ill call around for prices on coils around here. iv seen the same product go for anywhere from 16 bucks a pop to 90 a pop and even more at a stealership so ill have to call the local auto stores and see what type of deal i can get. is there any difference in quality between the different coils? would you all suggest one brand over another?

 

[TheMAN]

I know the BWD coils are japanese made... look exactly the same as the mazda OEM ones, so they might be made by the same supplier!

don't forget to replace the wires too... don't buy any of the cheap s*** at the parts stores... buy NGK wires (hard to find, so order online)

 

[Alejo_NIN]

shoot, i got this code today together with p0660, but it may have been that ir emoved the vac from it a few days ago.

p0300 scares the s*** out of me.

 

[Muderfahker]

I got the same error code: p0300, I just put new spark plugs in and never had a misfire since. 12$ fix, I would change that first even if the old ones still look new. Coils alone will cost you a hundred.

 

[Alejo_NIN]

my plugs are 2 weeks old.

 

[slavrenz]

I know the BWD coils are japanese made... look exactly the same as the mazda OEM ones, so they might be made by the same supplier!

don't forget to replace the wires too... don't buy any of the cheap s*** at the parts stores... buy NGK wires (hard to find, so order online)

RockAuto.com FTW

 

[hedlesschkn]

i got coils from carquest, 28 bucks a pop (they were the only place around that had two and didnt cost over 100 dollars each, gutta love the stealership prices...) and it seems to have fixed the problem, hopefully once and for all. ill keep you posted. must have just been a fluke that the coils worked fine every time i cleaned the egr valve

 

[Alejo_NIN]

so, i had a blinking MIL yesterday!
shat brix!

anyways, i guess it was a combination of unplugging the CTS and having misfires

 

[Alejo_NIN]

replaced coils, flushed radiator, new t-stat

let's see what happens next...

 

[hedlesschkn]

P0660 is Intake Manifold Tuning Valve Control Circuit, so whatever "vac i removed a few days ago" could certainly be your problem. and yeah p0300 scared the s*** out of me too, make sure you don't drive while misfiring or your going to make your catalytic converter crap the bed. speaking of which, does anyone know how to check how much life is left in your cat. i mean i know they have 9 lives but im not sure how many of them my misfiring adventure took (bah dump ching!)

 

[br289165]

Pull the green and white connectors on the left side of engine on top and clean them with a .22 cal borebrush, coat with dielc. grease.

P0660 is Intake Manifold Tuning Valve Control Circuit, so whatever "vac i removed a few days ago" could certainly be your problem. and yeah p0300 scared the s*** out of me too, make sure you don't drive while misfiring or your going to make your catalytic converter crap the bed. speaking of which, does anyone know how to check how much life is left in your cat. i mean i know they have 9 lives but im not sure how many of them my misfiring adventure took (bah dump ching!)

 

[Alejo_NIN]

ok, so when i left work yesterday, i stepped on it and there was no fuel cut....it was beautiful! car was pulling hard as ****. then on the 3rd try it started to do it again...thnks to the fuel cut my engine is not crapped out. i don't have cats, so no big deal.

speaking to someone, they mentioned that i may need to tune the afc to to compensate for the new FMIC.
i will be doing datalogs today and see what happens.

 

[Shub]

Same thing happened to me. It was the coils. It would randomly misfire while idling and while driving. EGR should only affect the idle if I'm not mistaken.