Throwing Error code P0303
02-22-2018, 04:24 PM
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Throwing Error code P0303
It tells me that cyl 3 is misfire, I swapped 2 & 3 coil pak and still throwing the same code cyl 3 misfire?
Check engine Light blinks at idle and code error repeats at about 50 miles. Car runs like a champ?
Any ideas what could be causing this?
Thanks
Check engine Light blinks at idle and code error repeats at about 50 miles. Car runs like a champ?
Any ideas what could be causing this?
Thanks
02-23-2018, 03:29 AM
#2
How many miles on the engine? Any recent work done or events occur with the car?
The way I think about this is to understand that a misfire is generally caused by lack of spark, lack of proper fuel/air mixture getting to cylinder, or lack of properly timed compression. In no particular order. There is a long list of possible causes for each of these possible conditions. We all think about spark first for some reason. The first thing I would do is to pull the spark plugs and examine their condition, that can tell you a lot. What do they look like? Does #3 look different than the others? Do they all look healthy? Are they oily? Black? Grey/brown? How old are they?
Depending on the outcome of that examination, decide what to do next to make the correct diagnosis. I would not just randomly start replacing things. Also, if you do start guessing and making changes, which is what we all sometimes fall into
, do one thing at a time.
The way I think about this is to understand that a misfire is generally caused by lack of spark, lack of proper fuel/air mixture getting to cylinder, or lack of properly timed compression. In no particular order. There is a long list of possible causes for each of these possible conditions. We all think about spark first for some reason. The first thing I would do is to pull the spark plugs and examine their condition, that can tell you a lot. What do they look like? Does #3 look different than the others? Do they all look healthy? Are they oily? Black? Grey/brown? How old are they?
Depending on the outcome of that examination, decide what to do next to make the correct diagnosis. I would not just randomly start replacing things. Also, if you do start guessing and making changes, which is what we all sometimes fall into
, do one thing at a time.
02-23-2018, 07:11 AM
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How many miles on the engine? Any recent work done or events occur with the car?
The way I think about this is to understand that a misfire is generally caused by lack of spark, lack of proper fuel/air mixture getting to cylinder, or lack of properly timed compression. In no particular order. There is a long list of possible causes for each of these possible conditions. We all think about spark first for some reason. The first thing I would do is to pull the spark plugs and examine their condition, that can tell you a lot. What do they look like? Does #3 look different than the others? Do they all look healthy? Are they oily? Black? Grey/brown? How old are they?
Depending on the outcome of that examination, decide what to do next to make the correct diagnosis. I would not just randomly start replacing things. Also, if you do start guessing and making changes, which is what we all sometimes fall into, do one thing at a time.
The way I think about this is to understand that a misfire is generally caused by lack of spark, lack of proper fuel/air mixture getting to cylinder, or lack of properly timed compression. In no particular order. There is a long list of possible causes for each of these possible conditions. We all think about spark first for some reason. The first thing I would do is to pull the spark plugs and examine their condition, that can tell you a lot. What do they look like? Does #3 look different than the others? Do they all look healthy? Are they oily? Black? Grey/brown? How old are they?
Depending on the outcome of that examination, decide what to do next to make the correct diagnosis. I would not just randomly start replacing things. Also, if you do start guessing and making changes, which is what we all sometimes fall into
, do one thing at a time.If the sparks look normal ---> Compression test (if that's normal) ---> Replace injector
Something like that. I feel like I've posted about how to diagnose misfires 5x's in the last few weeks; search is your friend, homie.
02-24-2018, 03:17 AM
#5
It is unfortunate that you don't know what the plugs looked like when they were changed. Did you change the plugs or someone else? What do the 30 day old plugs look like now? You should check them.
How long have you owned the car? What do you know about its past history?
Check the plugs. But, I'd say those compression results are poor and may be the cause of the misfires. You need to find out why the engine is not producing good compression. I have ideas about how to go about sorting that out, but I'm going to bow out and let others with more experience with this particular engine chime in.
How long have you owned the car? What do you know about its past history?
Check the plugs. But, I'd say those compression results are poor and may be the cause of the misfires. You need to find out why the engine is not producing good compression. I have ideas about how to go about sorting that out, but I'm going to bow out and let others with more experience with this particular engine chime in.
Last edited by rpg51; 02-24-2018 at 03:20 AM.
02-24-2018, 04:48 PM
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My car is a 2005 and I bought it new from the dealership. No negative history. I barely lift the hood. I commute from the Antelope Valley, CA to Hollywood, CA over the Los Angeles Crest mountain. About 115 miles round trip every day.
~John
~John
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