cel and a melted spark plug

[littlemimus]

So my car started misfiring super bad. I pulled all the spark plugs out and the electrode on cylinder 1 was like melted...so i changed all the spark plugs got new coils and the car is still misfiring like crazy. I figured it might be a bad tank of gas or a clogged injector so i seafoamed it and the car now idles (roughly) without me having to give it gas. any ideas what is going on? I did put gas at a place notorious for giving out bad gas because it was the only place i was close by and i ran out of fuel.

 

[BRIAN_MP5T]

In general letting the fuel run low increases the possibility that you will pick up everything in the tank and put it in the filter.

Luckly there is a white bucket, a plastic screen, a filter, then the pump. All injectors usually have a filter as well, but I find it hard to believe that "Bad Gas" is the current issue, unless you have not put new gas in it...

 

[destineal]

What was the cel?

 

[littlemimus]

not sure yet. i have to get the code read tomorrow.

 

[destineal]

Dude, you drive a MSP. Keep a code reader on you at all times.

 

[littlemimus]

Dude, you drive a MSP. Keep a code reader on you at all times.

i know. you think i would learn after 3 years of owning the car ha.

i pulled the codes and got a p0300, p0660 (something about intake mani tuning control ckt open (bank 1)) and a p0171 which is a lean code on bank one. which im sure is why the solenoid on the spark plug melted. i have no idea what the p0660 is.... i did a quick google search and they said its a solenoid for the vics or vtcs?

 

[tweety2300]

P0660 is for Vic's it will not throw a cel you've probly had it for awhile

 

[Dr0]

if you have a multimeter do a quick resistance test on all of your injectors they should be around 14k ohms i think, and if their bad the resistance will be wayyyy higher. And if one of your injectors is bad that cylinder will run lean and make the car miss like crazy.
And idk this is another educated guess but your pump may have overheated when you ran out of gas (the only thing that cools the pump internals is the gas...) and you might have shorted out one of the bars inside the pump and now its running lean bc the pump cant build appropriate pressure.

just my two cents (2cents)

 

[littlemimus]

P0660 is for Vic's it will not throw a cel you've probly had it for awhile

so i guess that isnt the culprit for the misfire.

if you have a multimeter do a quick resistance test on all of your injectors they should be around 14k ohms i think, and if their bad the resistance will be wayyyy higher. And if one of your injectors is bad that cylinder will run lean and make the car miss like crazy.
And idk this is another educated guess but your pump may have overheated when you ran out of gas (the only thing that cools the pump internals is the gas...) and you might have shorted out one of the bars inside the pump and now its running lean bc the pump cant build appropriate pressure.

just my two cents (2cents)

i didnt even think to check the fuel pump. ill check out the injetors and then the pump.

 

[littlemimus]

exactly how do i check ohms on the injectors? i have the tool but i have no idea how to hook the ground and the red wire up.

:edit nvm. i did the injector on cylinder 1 and it came up as 15.6 cylinder 2 was at like 15, cylinder 3 was at 18.7 almost 19 and injector 4 was at 15.3

 

[Dr0]

That's not bad, 3 is a little high though. Do this

Start the car and pull the number 3 injector and notice how the car reacts, then put the connector back and pull another cylinder

And when you pull them a -
Good injector with a good spray pattern = misfire+rough idle
Bad injector/clogged or dirty injector = little or no difference in idle

This is a single clyinder issue so if the injectors are good

Check compression
Perform a leakdown test on affected cylinder
Make sure all of you ignition components are in good condition

In all honesty the issue has to be with the fact that you ran out of gas assuming the car ran ok prior

Let me know what you find.

 

[hornsfan10609]

Did you get new spark plug wires or just coils? You probably need a new wire for the #1 cylinder.

 

[littlemimus]

Did you get new spark plug wires or just coils? You probably need a new wire for the #1 cylinder.

i replaced wires and coils. as well as spark plugs

That's not bad, 3 is a little high though. Do this

Start the car and pull the number 3 injector and notice how the car reacts, then put the connector back and pull another cylinder

And when you pull them a -
Good injector with a good spray pattern = misfire+rough idle
Bad injector/clogged or dirty injector = little or no difference in idle

This is a single clyinder issue so if the injectors are good

Check compression
Perform a leakdown test on affected cylinder
Make sure all of you ignition components are in good condition

In all honesty the issue has to be with the fact that you ran out of gas assuming the car ran ok prior

Let me know what you find.

so i disconnected injector 3 and started the car. it ran rough like its been misfiring so im assuming the injector is bad. can i use protege specific injectors or do they have to be specifically for the mazdaspeed?

 

[Dr0]

You misunderstood me.

When you unplug a GOOD INJECTOR the car will run rough(er)

And when you unplug a BAD/CLOGGED INJECTOR then the cars idle will NOT CHANGE OR SLIGHTLY CHANGE

 

[littlemimus]

You misunderstood me.

When you unplug a GOOD INJECTOR the car will run rough(er)

And when you unplug a BAD/CLOGGED INJECTOR then the cars idle will NOT CHANGE OR SLIGHTLY CHANGE

no i understood you. the car was idling rough already with all 4 injectors plugged in. i unplugged injector 3 as i suspected that one to be the culprit and it acted the same as if there was no change.

 

[hornsfan10609]

That test doesn't rule out an ignition misfire.

 

[Dr0]

But wouldn't it make sense to say that a lean condition caused the melted plug? I've never seen an ignition missfire melt a plug.. maybe foul it out and make the car run similar to what he is saying though.

 

[littlemimus]

update: just got the new injector. i will put it in and let you know what is going on.

 

[littlemimus]

so i put the new injector in. now the car doesnt even idle. rpms shoot up to like 3k and drop immediately. i pulled the spark plugs again and they are all pretty black.

there isnt any cel light flashing now but its still pretty rough a nd wont idle without me giving it gas...i plugged the code reader in and it says there are no codes now. idk what is going on with this car.

 

[CHIQLES]

did you disconnect the battery and reset ecu?