Emission relevant misfire misfire multiple cylinders
#1
Emission relevant misfire misfire multiple cylinders
Hey guys! I have an 02 disco 2. I recently picked it up with only 95k on the engine. When I first got it I bought an LRII reader because it had the three amigos. When I read the codes I found that it also needed a new MAFS. This was actually pretty easy to fix. New shuttle valve and boom. Amigos gone. New MAG boom. MAF code gone but now i have a slew of new codes that I think may be related.
Emission relevant misfire misfire multiple cylinders
Emission relevant misfire cyl 3
Emission relevant misfire cyl 5
Emission relevant misfire cyl 7
This seems odd to me because it came out of no where. No signs of any misfires just as soon as I finished the MAF the engine wouldn't stay on. It just turned off. I tried to read the codes but it just said misfire in cyl 7. I the. Tried to turn it on and give it some gas, which indeed kept the engine on but it sounded like there were misfires. So now I'm stuck thinking of how to fix it. Any ideas on where to start? It can't be as easy as spark plugs and distribution cap. Highly unlikely three go bad at once I think.
Thanks for the help!
Emission relevant misfire misfire multiple cylinders
Emission relevant misfire cyl 3
Emission relevant misfire cyl 5
Emission relevant misfire cyl 7
This seems odd to me because it came out of no where. No signs of any misfires just as soon as I finished the MAF the engine wouldn't stay on. It just turned off. I tried to read the codes but it just said misfire in cyl 7. I the. Tried to turn it on and give it some gas, which indeed kept the engine on but it sounded like there were misfires. So now I'm stuck thinking of how to fix it. Any ideas on where to start? It can't be as easy as spark plugs and distribution cap. Highly unlikely three go bad at once I think.
Thanks for the help!
#2
When you aren't giving it gas, what is the idle at and is it dropping low then shutting off? What type of fuel have you been running in it and what type of spark plugs are you using? There are numerous options that could cause this issue. The first being low quality gas. Secondly, a dirty throttle body. Thirdly, bad or dirty idle air control valve. Fourth, a fouled plug (some what common with the platinum 4's). Fifth, bad fuel flow to said cylinder. The list can continue to go on. I would first remove the spark plug and check it out. Then make sure it is clean and properly gapped. Make sure the ignition lead (spark plug wire) is connected properly and in good working order on both ends. You can verify that with a cheap plug tester.
#3
When you aren't giving it gas, what is the idle at and is it dropping low then shutting off? What type of fuel have you been running in it and what type of spark plugs are you using? There are numerous options that could cause this issue. The first being low quality gas. Secondly, a dirty throttle body. Thirdly, bad or dirty idle air control valve. Fourth, a fouled plug (some what common with the platinum 4's). Fifth, bad fuel flow to said cylinder. The list can continue to go on. I would first remove the spark plug and check it out. Then make sure it is clean and properly gapped. Make sure the ignition lead (spark plug wire) is connected properly and in good working order on both ends. You can verify that with a cheap plug tester.
#5
Good morning! Thanks for the speedy reply. I only run 91. Haven't put anything else in. Previous owner said the same thing. I checked out the throttle body when I replaced the MAFS. It looked real squeaky clean, almost as it the previous owner replaced it. When I'm not giving it gas it drops really low, rpm wise, then dies. In total it will run for about 30-45 seconds. I'm not sure how to get he actual codes, this is what my reader gives me.
#6
Did you plug the harness back into the new sensor?
Your truck doesn't have a distribution cap...
If you didn't have engine misfires before you replaced the MAF sensor then you forgot to plug something back in or you accidentally broke/unplugged something else.
Your truck doesn't have a distribution cap...
If you didn't have engine misfires before you replaced the MAF sensor then you forgot to plug something back in or you accidentally broke/unplugged something else.
Last edited by chubbs878; 01-29-2017 at 11:59 AM.
#7
yea I was afraid I messed something when I switched he MAF but i only saw the one cable for the MAF and there wasn't anything else around there that I saw.
#9
Hey there! Thanks for the reply. I was trying to reply earlier today but for some reason they aren't coming up. I'm pretty new to this forum thing. Moving on to some answers.
I always run 91. Previous owner claims the same. Throttle body looks great. I can pull the plugs and look at them tomorrow after work but I definitely found another problem earlier today. The breather hose popped out of the upper intake. I'm not too sure what actually happened to cause that though. It seems a little odd that it built up enough pressure to pop out. I can't even get it back in. Here's a picture of what I'm talking about.
I'm not sure if that will effect the cylinder misfires, but it definitely could help find the cause.
I always run 91. Previous owner claims the same. Throttle body looks great. I can pull the plugs and look at them tomorrow after work but I definitely found another problem earlier today. The breather hose popped out of the upper intake. I'm not too sure what actually happened to cause that though. It seems a little odd that it built up enough pressure to pop out. I can't even get it back in. Here's a picture of what I'm talking about.
I'm not sure if that will effect the cylinder misfires, but it definitely could help find the cause.
#10
alright, Ive been trying to post on my phone and it just hasn't been working lately so I'll try on the computer. Hopefully all my posts don't just pop up in a few days.
Luckyayb,
I only run 91, previous owner said the same thing. When I'm not giving it gas it just dies. Almost instantly. It tries to idle but just fails which made me think that there was something stuck in the IACV hose but there was nothing. I'm not too sure what spark plugs are in there but i can pull them and check if need be. I checked out the throttle body and it is squeaky clean. I will pull the hoses and check the IACV when i pull the plugs this weekend. I was reading the RAVE pretty thoroughly and it seems that the fuel injectors have the most similar symptoms so I'm leaning towards replacing them all. Another problem i found is that the breather hose just popped out of the plenum. No idea what could have caused this. it's a brass piece so its definitely been replaced before. i cant even get the thing back in there.
Luckyayb,
I only run 91, previous owner said the same thing. When I'm not giving it gas it just dies. Almost instantly. It tries to idle but just fails which made me think that there was something stuck in the IACV hose but there was nothing. I'm not too sure what spark plugs are in there but i can pull them and check if need be. I checked out the throttle body and it is squeaky clean. I will pull the hoses and check the IACV when i pull the plugs this weekend. I was reading the RAVE pretty thoroughly and it seems that the fuel injectors have the most similar symptoms so I'm leaning towards replacing them all. Another problem i found is that the breather hose just popped out of the plenum. No idea what could have caused this. it's a brass piece so its definitely been replaced before. i cant even get the thing back in there.