Cylinder #1 misfire! Please help!
01-09-2009, 02:07 AM
#1
Thread Starter
Join Date: Jan 2009
Location: TX
Posts: 10
Cylinder #1 misfire! Please help!
My 2001 V6 (around 68000 miles) had a SES light few months ago, and had no other symptoms. The code was pulled at Autozone and was P0153, which called for an O2 sensor1 in Bank2. I bought the thing ($54+) and I didn't know which was Bank2 since it had 4 (actually I did, but just didn't really have the time). So I just left it there and the light went away shortly.
Then couple of weeks ago when we had a severe cold day, and as I was driving, the car started jerking under load (when I gave gas) and it kept doing it under load. It wasn't apparent once it picked up the speed. The SES light also came on. This time the code was P301, which was Cylinder #1 misfire. I checked the spark plug, it looked okay, so where should I start? I can start changing the plug, wire, and eventually the coil pack, but I'd want to save as much money as I can. Has anyone experienced this problem? Could anyone please help? WhiteFoxGT?
thanks in advance. (sorry for the lengthy description... I am an electronic tech & I like to get as much info about any problems, so I thought it'd help)
Then couple of weeks ago when we had a severe cold day, and as I was driving, the car started jerking under load (when I gave gas) and it kept doing it under load. It wasn't apparent once it picked up the speed. The SES light also came on. This time the code was P301, which was Cylinder #1 misfire. I checked the spark plug, it looked okay, so where should I start? I can start changing the plug, wire, and eventually the coil pack, but I'd want to save as much money as I can. Has anyone experienced this problem? Could anyone please help? WhiteFoxGT?
thanks in advance. (sorry for the lengthy description... I am an electronic tech & I like to get as much info about any problems, so I thought it'd help)
Last edited by MustangBenoit; 01-09-2009 at 06:20 PM.
01-09-2009, 10:30 AM
#2
Resident Ginger
Join Date: Nov 2006
Location: Cali
Posts: 4,624
Well I would have replaced the O2 sensor sence it was giving you a cell to start with. Someone correct me if I am wrong, but that sensor is telling the computer about the exhaust leaving the cylinder, if that sensor is not working correctly the wrong info could be going to the computer, who in turn, is sending the wrong amount of air into the cylinder. Again this is just a shot in the dark.
Matthew
Matthew
01-10-2009, 09:48 PM
#4
Thread Starter
Join Date: Jan 2009
Location: TX
Posts: 10
I've heard about switching ignition wires on cylinders... Could some one please give me more info on this..
How can I switch the injecter line? where is it located?
The thing is, the original code (P0153) called for Sensor#1 in Bank#2, which corresponds to Cylinders 4,5,&6. Now the misfire is on Cylinder 1, (code P0301) which pertains to Bank#1, so, I am kind of confused as to whether to change O2 sensor or not... What if I just went ahead and change all 4 O2 sensors? (can't afford to b/c I am a student). I already checked the Plugs, and they seem just normal (no difference between the looks on them)... Any thoughts?
thanks...
How can I switch the injecter line? where is it located?
The thing is, the original code (P0153) called for Sensor#1 in Bank#2, which corresponds to Cylinders 4,5,&6. Now the misfire is on Cylinder 1, (code P0301) which pertains to Bank#1, so, I am kind of confused as to whether to change O2 sensor or not... What if I just went ahead and change all 4 O2 sensors? (can't afford to b/c I am a student). I already checked the Plugs, and they seem just normal (no difference between the looks on them)... Any thoughts?
thanks...
01-18-2009, 04:50 PM
#5
Thread Starter
Join Date: Jan 2009
Location: TX
Posts: 10
okay, so first I replaced all 6 plugs with Motor Craft ones ($4.69 from O'riley) with spacing (0.054) between them. I also added some fuel injector cleaner stuff (Lucas brand from Autozone - they sware that brand is the best, so I poured one bottle with a full tank of gas - Shell V-power (93 Octane)).
Then I test drove it, and it improved a lot, not much jerking but still had a little bit at the beginning of the acceleration in each gear.
So, I was like okay, now I should replace the wires as well. So I bought Motorcraft ($42.99 at O'Riley) plug wires and replaced them because some wires were touching other hoses and there are slow melts on them because of that. (But replacing them was not much fun, b/c the plastic clips and the slit wire covers are not easy to transfer to the new ones)
Anyway, I thought it should be perfect now that I have replaced the wires also. So I test drove, and found it still does that, but it has improved even better. It only jerks when at the beginning of the acceleration in each gear (especially in 3rd and if I switch to 4th gear and I didn't have enough speed). Once the speed is picked up, you don't notice anything.. Some times it doesn't even jerk (that is, no misfiring) and it does it only intermittently!
What do y'all think I should do next? Should I replace the coil pack? Or replace the O2 sensor? Should I replace all four O2 sensors? Would it be a good idea to replace them as part of maintanence for better performance? How long do they typically last and what brand would you suggest? The one I bought originally from Autozone was Bosch and I still haven't installed it as it says in my original post... The coil pack runs around $80 at O'Riley (not Motor Craft) and the O2 sensor at Autozone is around $49.99.
Please help because I am a college student and my classes have started already...
Then I test drove it, and it improved a lot, not much jerking but still had a little bit at the beginning of the acceleration in each gear.
So, I was like okay, now I should replace the wires as well. So I bought Motorcraft ($42.99 at O'Riley) plug wires and replaced them because some wires were touching other hoses and there are slow melts on them because of that. (But replacing them was not much fun, b/c the plastic clips and the slit wire covers are not easy to transfer to the new ones)
Anyway, I thought it should be perfect now that I have replaced the wires also. So I test drove, and found it still does that, but it has improved even better. It only jerks when at the beginning of the acceleration in each gear (especially in 3rd and if I switch to 4th gear and I didn't have enough speed). Once the speed is picked up, you don't notice anything.. Some times it doesn't even jerk (that is, no misfiring) and it does it only intermittently!
What do y'all think I should do next? Should I replace the coil pack? Or replace the O2 sensor? Should I replace all four O2 sensors? Would it be a good idea to replace them as part of maintanence for better performance? How long do they typically last and what brand would you suggest? The one I bought originally from Autozone was Bosch and I still haven't installed it as it says in my original post... The coil pack runs around $80 at O'Riley (not Motor Craft) and the O2 sensor at Autozone is around $49.99.
Please help because I am a college student and my classes have started already...
01-19-2009, 02:09 PM
#6
Thread Starter
Join Date: Jan 2009
Location: TX
Posts: 10
Okay so new developments:
I pulled out one connection at a time from the coil pack while the engine was running to see the sparks as I was advised in this forum... There is spark flying between the wires of cylinders 2-6, but not from #1!!! But when I pull it out (cylinder 1 connection) the engine rpm drops a little bit, though... and when I plug it back in, the rpm gets back to normal... So, does this mean the cylinder 1 is firing, but not very strong? But there are no sparks flying between them when I have it unplugged..
So, is it a bad coil pack? I thought I was told somewhere in this forum that if the coil pack is bad it would miss two cylinders... Could someone please help? It's kind of hard to get response on this forum quickly...
I pulled out one connection at a time from the coil pack while the engine was running to see the sparks as I was advised in this forum... There is spark flying between the wires of cylinders 2-6, but not from #1!!! But when I pull it out (cylinder 1 connection) the engine rpm drops a little bit, though... and when I plug it back in, the rpm gets back to normal... So, does this mean the cylinder 1 is firing, but not very strong? But there are no sparks flying between them when I have it unplugged..
So, is it a bad coil pack? I thought I was told somewhere in this forum that if the coil pack is bad it would miss two cylinders... Could someone please help? It's kind of hard to get response on this forum quickly...
12-15-2009, 10:40 AM
#7
Join Date: Dec 2009
Location: SC
Posts: 1
Whoever told you about the two cylinder misfire is correct. Thus V6 Mustangs have waste spark systems which means that ONE coil in the pack fires TWO cylinders in the engine.
Back to the O2 sensor for a minute. It tells the cars computer about the Air/fuel ratio going into the cylinders and gives feedback to the computer. If it's too low or high, the computer changes the output of the injectors. I don't think the injectors are individually controlled, meaning, if it was the O2 sensor, the ENTIRE bank would misfire.
You said you're good with electronics. I'd measure the resistance over the coil pack secondary circuits (where the plug wires go into the coil pack) and across the plug wires themselves. The coil pack should be around 11-14k Ohms per coil. Each plug wire should have no more than 1k Ohms per foot. The lower the resistance in the wires, the hotter the spark, which means no misfire
(given that there IS a correct A/F ratio). If you check the wires and they're high on the resistance, I'd change them to a lower resistance wire (Accel makes good ones, but i'm sure someone at the parts house can help you). If the coils are high on resistance, check where the plugs go on them and look for corrosion. If they look good, then it's probably bad.
I'm having close to the same problems with my car at the moment. Hope this helps!
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Fox-4 Ford Freak
Back to the O2 sensor for a minute. It tells the cars computer about the Air/fuel ratio going into the cylinders and gives feedback to the computer. If it's too low or high, the computer changes the output of the injectors. I don't think the injectors are individually controlled, meaning, if it was the O2 sensor, the ENTIRE bank would misfire.
You said you're good with electronics. I'd measure the resistance over the coil pack secondary circuits (where the plug wires go into the coil pack) and across the plug wires themselves. The coil pack should be around 11-14k Ohms per coil. Each plug wire should have no more than 1k Ohms per foot. The lower the resistance in the wires, the hotter the spark, which means no misfire
(given that there IS a correct A/F ratio). If you check the wires and they're high on the resistance, I'd change them to a lower resistance wire (Accel makes good ones, but i'm sure someone at the parts house can help you). If the coils are high on resistance, check where the plugs go on them and look for corrosion. If they look good, then it's probably bad. I'm having close to the same problems with my car at the moment. Hope this helps!
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Fox-4 Ford Freak
12-15-2009, 11:58 AM
#8
I doubt your O2 sensor is bad. Just because a part throws a code doesn;t mean it's broken, it usually means it's working perfectly and seeing a problem with something else. Your coil is most likely out, go with a motorcraft coil. Also, check your MAF, and clean it out, it can cause a lean condition when it's dirty.
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