Multiple codes, car running rough

[Graham19922011]

06 GT, Cam’s x pipe pulleys cai. I’ve had random misfire for few days but can’t hear it thru any rpm. Driving steady in 5th yesterday and car started running super rough missing bad and check engine started flashing. Got p300 p301 p302. Loss in power, didn’t depend on rpm. Checked the codes and missing on #1 and #2. Was gonna find a place to pull over but it cleared right up. Done this couple times throughout the day and cleared up within 20 seconds. Stock coils, plugs changed less than 20k or so. We had front timing cover off last month changed out all timing components chains guards gears etc but has ran great since then. Any ideas on what’s going on?


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[nawagner]

Double check all of the COP connectors to make sure they are tight. Also make sure the boots are seated tight.

Also double check any connector that you may have disconnected during the work last month.

Does the weather, like rain, have an impact on how it runs?

 

[86GT351]

Double check all of the COP connectors to make sure they are tight. Also make sure the boots are seated tight.

Also double check any connector that you may have disconnected during the work last month.

Does the weather, like rain, have an impact on how it runs?

Good suggestions. You have a Random code, Cylinder 1 and Cylinder 2 code. 1 on each bank of the engine. Probably related to each other.

 

[redfirepearlgt]

Good suggestions. You have a Random code, Cylinder 1 and Cylinder 2 code. 1 on each bank of the engine. Probably related to each other.

FYI - Cylinder one and two are both on bank 1 (passenger side, front 2 jugs).

 

[RocketcarX]

If the car has been fine for several thousand miles then take the codes for what they are, likely indicators that you have 2 failing coils.
Often when people do plugs they neglect to replace the coil boots, a good place to start would be two new ignition coils and replacing the other 6 ignition coil boots.
You could watch the misfire counter if you have a good enough scan tool, but the misfire codes tend to be there because of failing coils.

 

[Juice]

I would swap coils. Move 1&2 to cylinders 3&4 (3&4 > 1&2) If you have failing coils, the codes should move with the coils. If the codes stay with 1&2, you will know it is NOT the coils.

 

[86GT351]

FYI - Cylinder one and two are both on bank 1 (passenger side, front 2 jugs).

Early morning Brain Fart. LOL!

 

[Graham19922011]

Double check all of the COP connectors to make sure they are tight. Also make sure the boots are seated tight.

Also double check any connector that you may have disconnected during the work last month.

Does the weather, like rain, have an impact on how it runs?

I don’t drive in rain or bad weather and it’s only done this on a 80 degree sunny day twice. Drove over an hour back home and it didn’t repeat itself. Somebody on another forum suggested we didn’t tighten crank bolt down enough? And the exciter gear could be causing issues?


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[Graham19922011]

If the car has been fine for several thousand miles then take the codes for what they are, likely indicators that you have 2 failing coils.
Often when people do plugs they neglect to replace the coil boots, a good place to start would be two new ignition coils and replacing the other 6 ignition coil boots.
You could watch the misfire counter if you have a good enough scan tool, but the misfire codes tend to be there because of failing coils.

What are the odds both coils stop working at the exact same time and then simultaneously start working again 20 seconds later? Could this be alternator related? I’ve not had good luck with this car and alternators. I’m gonna switch coils around anyway


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[07 Boss]

When I re-wired my engine bay I broke a couple of the release clips on a couple of connectors. They went on nice and felt snug and don't realize they were broke. They get pretty brittle with the engine heat and probably broke while reconnecting them. Anyways, at weird moments she would start running rough and bucking, and then settle back again like every thing was good. Got misfire codes. Went to move the injectors around to help diagnose and that is when I found the broken connectors. But the misfire was intermittent and random. I figured that at certain times the motor vibration would back them out but then they would slide back down and start working again.

 

[86GT351]

I don’t drive in rain or bad weather and it’s only done this on a 80 degree sunny day twice. Drove over an hour back home and it didn’t repeat itself. Somebody on another forum suggested we didn’t tighten crank bolt down enough? And the exciter gear could be causing issues?


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Anything is possible. The exciter works off of air gap. It can surely cause a misfire concern randomly.

 

[redfirepearlgt]

Early morning Brain Fart. LOL!

I thought you may have been having a GM moment on the wrong site. LOL!

 

[nawagner]

I would swap coils. Move 1&2 to cylinders 3&4 (3&4 > 1&2) If you have failing coils, the codes should move with the coils. If the codes stay with 1&2, you will know it is NOT the coils.

This is the next test that should be done.

 

[RocketcarX]

Like said swapping the coils is the 1st step to diagnosing bad coils (I just assumed this was done), making sure the plugs are tight is a good idea too.
Yes, the alternator can cause weird issues, it did on my car.

 

[Graham19922011]

I hope it’s not alternator. I just put a nice one in last year. And battery. I switch coils around and next day I’m off in good weather I’ll clear the codes and take a good drive to see if it pops up. How would I go about diagnosing a random misfire?


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[redfirepearlgt]

swap coils 1,2 with 3,4. If problem moves to 3,4 its the cop's or the boots on the cop's. if it stays with 1,2 then you know its not the COPS. You may also check your DC voltage output with a voltmeter and see what it is reading.

 

[Juice]

I hope it’s not alternator. I just put a nice one in last year. And battery. I switch coils around and next day I’m off in good weather I’ll clear the codes and take a good drive to see if it pops up. How would I go about diagnosing a random misfire?


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If it is NOT the COPS, then you are likely looking at a fueling issue with #1&2. If it is an engine mechanical issue, it is not likely it would be intermittent. (any COPS that failed on my cars were always a "hard" misfire btw)

I would take a close look at injector power and ground circuits. Do a "wiggle test" as Ford calls it on the engine harness. With the engine idling, move the wiring around and see if you can get the engine to stumble/ throw the CEL on.

You may have a "multi cylinder misfire" condition, but the PCM goes into limp mode before all codes are set, and only see the misfire on #1&2. In my experience, fault codes do not always point to the exact cause. Loss of fuel pressure will cause a misfire. I would replace fuel filter as a cheap maintenance item.

You could have a fuel pump going out, but that is not so cheap to just replace on a guess.

Also possible, you may have a little water in the fuel tank, and it makes it to the engine under certain conditions.

Just throwing ideas out from past experience. You need 3 things for an engine to run: Fuel, Spark, and Compression. Any one of those with an issue, and you have a misfire/no fire condition. Not sure if it has been done, but doing a compression test on that bank is also a good idea.

 

[nawagner]

The next thing to check after the COPs is the spark plugs. Do the same with them that you do with the COPs. Move and see if the problem follows. Not likely to have two go bad at once but I have had it happen.

If not COPs or plugs then on to the items JuIce mentioned.

Alternator problems usually just throw codes, and don’t usually make the car run bad.

 

[Graham19922011]

If it is NOT the COPS, then you are likely looking at a fueling issue with #1&2. If it is an engine mechanical issue, it is not likely it would be intermittent. (any COPS that failed on my cars were always a "hard" misfire btw)

I would take a close look at injector power and ground circuits. Do a "wiggle test" as Ford calls it on the engine harness. With the engine idling, move the wiring around and see if you can get the engine to stumble/ throw the CEL on.

You may have a "multi cylinder misfire" condition, but the PCM goes into limp mode before all codes are set, and only see the misfire on #1&2. In my experience, fault codes do not always point to the exact cause. Loss of fuel pressure will cause a misfire. I would replace fuel filter as a cheap maintenance item.

You could have a fuel pump going out, but that is not so cheap to just replace on a guess.

Also possible, you may have a little water in the fuel tank, and it makes it to the engine under certain conditions.

Just throwing ideas out from past experience. You need 3 things for an engine to run: Fuel, Spark, and Compression. Any one of those with an issue, and you have a misfire/no fire condition. Not sure if it has been done, but doing a compression test on that bank is also a good idea.

Awesome thanks a lot I’ll look into it. Haven’t had a chance to drive the car yet to see if it’ll swap sides. Compression check is next.


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[2526Bullitt]

I have had a similar issue, although mine occurred right after changing the spark plugs.... did the coil switch-@-ro and the missfire stayed with the same cylinders...i had two bad spark plugs. Its worth your time moving the coils around.