View Full Version : Random misfire codes
Blackened300a
08-20-2017, 07:15 AM
Just recently this has been happening. I took the car out 3 weeks ago to a car meet and on the way there, the check engine light came on for #3 cylinder misfire and a misfire under 1K RPMs. I didn't feel anything from the engine and it idled smooth. I cleared the code and it didn't come back on.
I took the car out last weekend and no codes and no issues at all. Last night I take the car out and I get a check engine light for misfire on cyl #5 and a P3060 code which I can't find anything online about what it is. It seems to be a catalyst code which I think may be related to the misfire. I cleared it and then proceeded to drive the car another 50 miles and the code never came back and the engine felt smooth the entire time even before the light came on.
The plugs have all been replaced with new NGKs when I did the blower install 3 years ago and maybe less then 3000 miles, the coils were all replaced at the same time about 4 years ago and 3500 miles using motorcraft coils, the wiring harness behind the head is secure and not rubbing so that's ruled out, the injectors were flowtested low mile 39lb with less then 10k miles total, I can't figure why the misfire codes would randomly jump from one bank to the other and the engine idles and runs smooth. I don't think coils would all start to fail at the same time, could this be MAF related or fuel?
Thanks for any info.
justbob
08-20-2017, 03:57 PM
Check your main engine harness, mine had some oxidation on some of the terminals a few years ago and cleaning them up rid my weird misfire issues.
I've also had to repair an on off miss on Cyl 4 due to how the wiring turns to plug into the coil and found one of the wires had finally pinched in half at the bend.
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Blackened300a
08-20-2017, 05:20 PM
Check your main engine harness, mine had some oxidation on some of the terminals a few years ago and cleaning them up rid my weird misfire issues.
I've also had to repair an on off miss on Cyl 4 due to how the wiring turns to plug into the coil and found one of the wires had finally pinched in half at the bend.
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I actually checked the main harness plug recently because my center console power point stopped working and there was no corrosion and clean contacts. Im going to wait til the next time a code comes up and see if it jumps to another cylinder. I just find it odd that it's misfiring from bank to bank and the engine is running smooth the entire time.
Mr. Man
08-20-2017, 05:51 PM
Code for the Fusion, but codes can be generic. Might be worth checking into, symptoms seem similar. Also noted a C-3060 code can be related to a failing catalytic converter, check the sensor for trouble.
Symptoms
Symptoms of a P3060 Ford Fusion diagnostic trouble code may include:
Vacuum leak on the engine
Reduction in engine performance, especially at low RPM levels
Engine surge
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Possible Causes :
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
Blackened300a
08-20-2017, 08:10 PM
The only other thing I'm leaning towards is a tank of bad gas. I only got 240 miles to a tank full this fill up when I'm usually 325 to a tank. I'm also on the same tank full that I got two random misfire codes so it's making it suspect. I put gas in it last night so let's see if that improves it.
The only other thing I'm leaning towards is a tank of bad gas. I only got 240 miles to a tank full this fill up when I'm usually 325 to a tank. I'm also on the same tank full that I got two random misfire codes so it's making it suspect. I put gas in it last night so let's see if that improves it.
How do you get 325 to a tank with a Blower? WTF
Motorhead350
08-21-2017, 11:51 AM
How do you get 325 to a tank with a Blower? WTF
No more than 1/8 throttle for the whole tank. Make sure it doesn't down shift to make a highway pass and keep A/C to a minimum.
fastblackmerc
08-21-2017, 12:15 PM
Paul, check the harness at the rear of the drivers side cam cover. It's been known to rub on the long bolt there. I cover the bolt with a rubber vacuum cap.
Mr. Man
08-21-2017, 02:00 PM
Just recently this has been happening. I took the car out 3 weeks ago to a car meet and on the way there, the check engine light came on for #3 cylinder misfire and a misfire under 1K RPMs. I didn't feel anything from the engine and it idled smooth. I cleared the code and it didn't come back on.
I took the car out last weekend and no codes and no issues at all. Last night I take the car out and I get a check engine light for misfire on cyl #5 and a P3060 code which I can't find anything online about what it is. It seems to be a catalyst code which I think may be related to the misfire. I cleared it and then proceeded to drive the car another 50 miles and the code never came back and the engine felt smooth the entire time even before the light came on.
The plugs have all been replaced with new NGKs when I did the blower install 3 years ago and maybe less then 3000 miles, the coils were all replaced at the same time about 4 years ago and 3500 miles using motorcraft coils, the wiring harness behind the head is secure and not rubbing so that's ruled out, the injectors were flowtested low mile 39lb with less then 10k miles total, I can't figure why the misfire codes would randomly jump from one bank to the other and the engine idles and runs smooth. I don't think coils would all start to fail at the same time, could this be MAF related or fuel?
Thanks for any info.
Paul, check the harness at the rear of the drivers side cam cover. It's been known to rub on the long bolt there. I cover the bolt with a rubber vacuum cap.:fishslap:
MyBlackBeasts
08-21-2017, 02:39 PM
How do you get 325 to a tank with a Blower? WTF
I Got 400ish highway to a tank with the canned Trilogy tune. 24mpg.
300 now after dynotune, 17mpg highway.
Comin' in Hot
08-21-2017, 04:55 PM
I Got 400ish highway to a tank with the canned Trilogy tune. 24mpg.
300 now after dynotune, 17mpg highway.
It's totally possible, I just got 391 today and filled it back up with 17.5 gallons on my way back from the Woodward Dream Cruise.
Blackened300a
08-21-2017, 10:27 PM
I left out something that I didn't think as anything major. Recently my engine has been having a "crank no start" issue at random times. It's happened 3 times where the engine would just crank over and over but not start. I would let off the key, hit it again and it would fire right up. Going with the random hard starts, bad gas mileage, and now the misfire codes, I'm leaning towards a faulty crank position sensor. I ordered a new motorcraft one up and see what happens.
MOTOWN
08-21-2017, 10:36 PM
I left out something that I didn't think as anything major. Recently my engine has been having a "crank no start" issue at random times. It's happened 3 times where the engine would just crank over and over but not start. I would let off the key, hit it again and it would fire right up. Going with the random hard starts, bad gas mileage, and now the misfire codes, I'm leaning towards a faulty crank position sensor. I ordered a new motorcraft one up and see what happens.
I was saying crank sensor in my mind before I finished reading your post , another members car was doing the exact same thing and it turned out to be the crank sensor.
Blackened300a
08-26-2017, 10:45 AM
Update......
Swapped out the crank position sensor this morning. I drove the car about 30 miles, hard throttle, light throttle, sitting in traffic and open road, no check engine light.
I also noticed the engine started faster, idle is much smoother, I had a slight shudder when the car would idle at a traffic light, that's cleared up, the gas gauge did not move after driving the car hard. So gas mileage is definitely back to normal and I have a noticeable amount of power back in the car.
Before it was feeling sluggish which I thought was because of the heat and humidity. I took it out today and it spins tires at 1/4 throttle and pulls so much harder through the gears. This sensor may have been bad for quite a while for all I know and the misfire codes finally brought it to light. I'll drive the car some more to be certain but overall the engine feel so much smoother and drivability feels much better.
Blackened300a
06-15-2018, 02:36 AM
This problem is not solved.
I’m still getting a misfire code on cylinder #5. It started out with #3 and #5 misfires but a coil swap on #3 took care of that and that code never came back.
I’ve swapped the spark plug from #5 to cylinder #6, new coil, went back to the stock coil connector, ECM was sent out, tested and came back with nothing wrong with it, and the crank position sensor was replaced.
It’s totally random, before it was under 1K RPMs, now it’s under normal driving. A few weeks ago I put over 200 miles on the car with no codes or issues, then the light came on. I checked the coil to make sure it’s connected and I got a pending code for cyl #5 within 100 miles.
The engine runs smooth and has all its power, just keep getting this code. Any idea? It’s nearly a year that I been chasing this and I can’t get the car inspected because the CEL comes on before the monitors can set.
Thanks for any info.
Invective
06-15-2018, 04:13 AM
I left out something that I didn't think as anything major. Recently my engine has been having a "crank no start" issue at random times. It's happened 3 times where the engine would just crank over and over but not start. I would let off the key, hit it again and it would fire right up. Going with the random hard starts, bad gas mileage, and now the misfire codes, I'm leaning towards a faulty crank position sensor. I ordered a new motorcraft one up and see what happens.
Had this situation happen with my previous Mustang. Load tested the battery and it was borderline, even after a full charge. It was explained to me that within the power distribution scheme of things, power goes first to the starter then the ecm - weak battery will turn over the motor but will fail to power up the ecm correctly.
Repeated attempts may prime the battery a bit to coax out enough power to light up the ecm. New, fully charged battery corrected the issue. Whenever I 'fully charge' a battery for testing, I 'top it off' with a Battery Tender or any similar type 'smart charger' as they will push the battery to 'full capacity' vs. about 80% for the alternator and standard chargers.
Invective
06-15-2018, 04:23 AM
I Got 400ish highway to a tank with the canned Trilogy tune. 24mpg.
300 now after dynotune, 17mpg highway.
Please tell us the differences in performance/feel between the 'canned' tune' and the dyno tune. I was talked into a $600 dyno tune on my '98 and it honestly didn't 'feel' any different than the 'canned tune' (chip) I bought from Superchips - my mileage went down also. Canned Superchips tune on my '05 and burning 93 E0 returned 27mpg highway driving 70-80mph through the VA and WVA hills (trip computer) on my Michigan trip to retrieve the Marauder this past March.
Blackened300a
06-15-2018, 04:32 AM
Had this situation happen with my previous Mustang. Load tested the battery and it was borderline, even after a full charge. It was explained to me that within the power distribution scheme of things, power goes first to the starter then the ecm - weak battery will turn over the motor but will fail to power up the ecm correctly.
Repeated attempts may prime the battery a bit to coax out enough power to light up the ecm. New, fully charged battery corrected the issue. Whenever I 'fully charge' a battery for testing, I 'top it off' with a Battery Tender or any similar type 'smart charger' as they will push the battery to 'full capacity' vs. about 80% for the alternator and standard chargers.
I haven’t had the hard start issue in over a year. The battery is only 2 years old and it’s starting up fine every time. Just misfire issue is the only problem.
1Marauder
06-15-2018, 06:27 AM
The only other thing I'm leaning towards is a tank of bad gas. I only got 240 miles to a tank full this fill up when I'm usually 325 to a tank. I'm also on the same tank full that I got two random misfire codes so it's making it suspect. I put gas in it last night so let's see if that improves it.
This was what I was thinking. Bad gas... Have you burned through this tank, or added a gas treatment (Seafoam or Redline)?
Blackened300a
06-15-2018, 08:38 AM
This was what I was thinking. Bad gas... Have you burned through this tank, or added a gas treatment (Seafoam or Redline)?
I’ve went several tanks of gas and still getting the single cylinder misfire. I’m taking the car out tonight after swapping another coil in last night and see if it pops the code or maybe I’ll get lucky and solved my issue. I’m not holding my breath though.
justbob
06-15-2018, 08:41 AM
Intermittent stuck or failing injector?
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Blackened300a
06-15-2018, 09:05 AM
Intermittent stuck or failing injector?
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I would agree just I don’t feel it missing. It runs smooth, has all its power and nothing unusual with the way it performs. The next step was swapping the #5 with #6 and see if the misfire code follows. Just doing that on a trilogy isn’t very fun at all.
BLACKMARAUDER04
06-15-2018, 11:01 AM
It may be the Idle Air control or your Fuel pump is shutting off
intermittently. That would result in the no start.
justbob
06-15-2018, 01:21 PM
I would agree just I don’t feel it missing. It runs smooth, has all its power and nothing unusual with the way it performs. The next step was swapping the #5 with #6 and see if the misfire code follows. Just doing that on a trilogy isn’t very fun at all.
I agree. I don’t miss mine whatsoever! I was just spit balling.
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Blackened300a
06-15-2018, 03:22 PM
Took the car out for a ride tonight. I set the catalyst monitor and then I scanned it for good measure and the pending code was cleared. I ran to my friends shop, got it inspected and so far so good. Random.
Invective
06-15-2018, 06:22 PM
I would agree just I don’t feel it missing. It runs smooth, has all its power and nothing unusual with the way it performs. The next step was swapping the #5 with #6 and see if the misfire code follows. Just doing that on a trilogy isn’t very fun at all.
If it ain't broke don't fix it.....
Blackened300a
06-16-2018, 08:56 AM
If it ain't broke don't fix it.....
LOL. damn pending code came back this morning. The freezeframe said the engine was idling at 0 road speed at 190*. I’m wondering if that injector is the issue and is clogged or not spraying properly since it’s at the end of the line of the rail. I just changed the fuel filter three weeks ago and it was clean.
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