left key on three days, after jump starting it, it runs rough and misfires?

Hi,

Have you fully recharged the battery? If it was completely drained, the alternator may have trouble recharging it.

Also, how long have you driven it? When the battery is disconnected and reconnected, some abnormal drive symptoms may occur while the vehicle relearns its adaptive strategy. The vehicle may need to be driven for a while to relearn its strategy. I realize you didn't disconnect it, but if it was fully drained, it is basically the same.

Let me know.

Joe

Yes, it was drained. I have fully charged it and have driven it a few miles but it runs so rough I'm concerned that it will stop and strand me.

Hi,

By chance, has the check engine light turned on? When you charged the battery, was it disconnected? Did you physically remove the battery to charge it?

Sorry for so many questions. I'm trying to narrow things down.

Let me know.

Joe

The check engine light did not come on until after I drove it. The battery was not disconnected when I charged it. The codes thrown were all misfire codes.

Hi,

Wow, this is an interesting one. Since it is running this way and you have misfire codes, it could be an issue with the alternator not producing enough.

Let's start by testing the alternator. All you will need is a voltmeter or multimeter. Here is a link that explains how it is done:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

If that checks good, let me know. You may need to have the PCM flashed. I'm not sure why a drained battery would cause anything, but anything is possible.

Let me know

Joe

Alternator works fine-14.6 volts. The only code my obd2 is now reading is P0302. I've cleared it a few times and drove some. It comes back flashing within a mile. So, for sure # 2 is not firing at all.

Hi,

Remove the cylinder 2 spark plug and see if it is wet, damaged, or anything out of the ordinary. If it appears good, confirm it is getting spark.

Here is a link that explains how that is done:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

If there is no spark, switch cylinder 1 and 2 coil packs to see if the misfire changes location. If it does, replace the coil pack.

If you do have spark, we need to check if it is getting fuel.

Here is a link that explains how to test an injector:

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

If you look below, I attached the injector schematic. Note that each injector has a red wire. That is the power supply. That is the wire on the injector to check first when the key is in the run position. It should have 12v constant. If it does, then we need to check if the PCM is providing a ground path.

To do this, disconnect the injector connector. Cylinder 2 will have a red wire and also a white wire. Take a test light and connect the alligator clip to the positive battery terminal. On the opposite end of the test light, touch the white wire. Do this while a helper cranks the engine. If the PCM is providing a ground path, the light will flash on and off.

Last, if all the above checks were good, we need to check engine compression in that cylinder. We will cross that bridge if needed.

Let me know what you find.

Joe

I had a coil pack laying around, so I put it in. Ran good for 2 minutes then P0302 again. I did the listening test on the injector, and it pinged away just like the rest. I haven't done the other injector tests yet. I haven't taken the plug out either. It's a ford 5.4 L 3 valve Triton. The one that is infamous for broken plugs and big bucks to get them extracted. Looks like I've got no choice but to pull the plug and hope it's in one piece?

Hi,

When it ran good for two minutes, was the engine running smoothly? Also, when the check engine light returned, did you feel the misfire?

If that is the case, my first suspect would be a connector issue at the coil pack. If you can feel and hear the misfire, with the engine running, move the wiring harness around to see if you notice a change.

And yep, the plugs are a nightmare. However, at this point, I don't see a need to remove it just yet. A spark plug won't start working properly for a time and then stops.

Let me know.

Joe

I can try that, but I have pulled the coil pack and put in a new one. I tested the spark from the new pack against a ground and the spark jumped a half inch. I can feel the miss in the motor but i can't hear it. What i said I heard the other day was the injector clicking- using the screwdriver to the ear trick. It sounded like all the rest of injectors. I do have a cheap scanner that was gifted to me. It's a 'Launch Creader professional 129X'. I'm not sure if it'll yield any valuable info but I can figure out how to use it. It's better than my $20.00 OBD2 meter.

I've tested all the coil and injector electric issues, and they all look okay. So, the injector is getting the signal, but could it still be clogged? Also, to check compression I would still need to remove the spark plug. I put a 9/16 plug socket on it today. I pulled on it at 25-foot pounds after soaking it with PB Blaster and sea foam for 3 hours. It didn't budge. Any idea what the max torque that can be used without breaking it?

Hi,

It wouldn't hurt to try the scan tool to see if there is something other involved. However, since you have a good spark and you hear the injector working, I suspect the plug needs to be removed. Do you have any idea how old they are?

Also, I'm not sure what torque would be max. The 25 Ft/lbs is the spec for tightening them. I wouldn't go much more.

If you want to try something, I always have success when I use a product called freeze-off by CRC. It actually lowers the temp of the item being removed to cause it to contract. Basically, it does the opposite of heat. LOL

I attached a pic of it below. Also, I don't work for CRC. LOL I just like the product.

Try it. Make sure to follow the directions. It really is amazing how well it works. Now that I said that, it won't work. Ugh!!! LOL

Let me know.

Joe

see pic below.

I don't remember how long ago I had them changed but it was at a Ford dealership and around 40,000 miles ago. It was right after they lost the class action suit. I'll give the freeze thing a try. Thanks

Hi,

What a design. Try the freeze-off and let me know if it helps.

Take care,

Joe

One more quick note before I break a plug. Now when I start it the engine runs smooth for about one minute before it misses. Any thoughts?

Did you notice any gray spots on the rubber boot that covers the spark plug? You would have needed to check while the coil pack was removed.

If you did, you may have ignition spark arcing through the boot. Let me know.

Joe

I haven't pulled the plug yet, but my scanner is showing an injector error on number 2. That may explain the few occasional times it runs smooth for a few seconds?

Hi,

That certainly could be the issue. By chance, do you remember the code that was found? If you have it, I can look into possible causes and diagnostics.

Hopefully, you can get this going without removing the plug.

Let me know.

Joe

I'm going to run it again, but it said Injector circuit error cylinder 2 and Bank 1 too lean. I doubt the cause is bank 1 too lean as it is just one cylinder with a constant misfire.

The idea that it has a lean mixture issue leads me to believe the injector is bad. If it was a vacuum leak, which is very common, it would likely be a random cylinder misfire code. The same if it was a fuel pressure issue.

Here is what to do. Locate the cylinder 1 fuel injector and disconnect the electrical connector. It will have two wires, one is red and the other tan. Using a test lamp, check the red wire for voltage with the key in the run position. It should have 12v constantly with the key on. If it does, then do this.

Take the alligator clip of the test lamp and attach it to the battery + terminal. Probe the tan wire with the light. At this point, it should not light. Have a helper crank the engine. If we are getting a ground path from the PCM, the lamp should flash.

Note that all injectors get power from the same place, so it isn't a lack of power, but it may be lost at that one injector.

Let me know what you find.

Joe

See pic below.

I've pretty much done all that and rerouted some injector wires that were stretched around a coil pack. It runs pretty good when cold but not so good when warm. I hooked it to my boat and went to the lake. It misses a lot when its lugged and first give it gas then gets better a bit when stomp on the gas or shut of the overdrive. It does show a code for random misfire, but most misfires are still on #2 cylinder and some on #3. It does show lean on bank #1. I have done every test for vacuum leak and can't find one. Rail pressure is 39 PSI on both sides. Scanner shows EGR and MAF to be okay. As for spark plugs, I called Ford dealership, and they say $800.00 plus, time and material for whatever they break.
It's getting more confusing by the minute!

They want $800.00 plus what they damage or break? OMG!

If you have a lean mixture on only one side, I wonder if you have an exhaust leak pre-catalytic converter. That can cause a lean O2 reading.

What are your thoughts on removing the injectors for the affected cylinders?

Take a look at this link:.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Also, listen for any kind of exhaust leak on bank 1. They have a history of exhaust manifold leaks.

Joe

Well, It's getting better. The injectors look good. It doesn't miss during normal driving but when I hit passing gear or if I lug it in OD it starts missing. Let me give you some numbers and see If you think I may have a week MAF sensor. (752 rpms) LTFT1 4.3% LTFT2 8.5% STFT1 5.22% STFT2 5.75% BARO 147.5hz. I'm at 900' above sea level I was told the BARO should be 160-170 at this altitude.
what do you think??

Hi,

I agree. Just for curiosity, how does it run with the MAF disconnected?

Joe

When I unplug the MAF the engine shuts off but I can restart it with the MAF still unplugged and it seems to run fine. I haven't drove it that way. Anyway, It's running better now and I don't know why. I drove it about 30 miles yesterday and it didn't throw any codes. It still lacks power and bank 1 reads lean on my scanner while engine is running.
It is confusing for sure.

Hi,

When the MAF is disconnected, check to see if the rich fuel mixture falls closer to normal.

Joe

Okay, will do. I forgot to mention I reset the elec throttle relearn. I don't think that has anything to do with why it's running better. Gonna check the fuel mix with MAF off in a bit.

If we only have one side that is lean, are you certain there isn't an exhaust leak on the lean bank pre-catalytic converter?

Let me know.

Joe

I'm not sure of anything now. The problem started when I left the key on for three days. After checking everything all I've really done is put in some coil pacs-didn't-seem to help. Cleaned the MAF and throttle body-didn't help. reset PCM-didn't help much. A few other minor things-ran a little better. I loaded the fuel with sea foam hoping it would loosen the plugs. Gradually it was getting a little better. Later today the fuel trims were okay, and I got lean on both banks. It didn't throw a code p0171 or p0174. It was the data stream on my scanner that said lean. This evening it was running pretty good-a little vibration at idle but no noticeable miss while driving. I'm not saying it's fixed but i'll know when i hook my boat to it. I really have no Idea why it's running better unless the sea foam cleaned the injectors, or did it take the PCM that long to relearn everything?
It's been nuts.

Oh, after I plugged the MAF back in it would idle at 8.g/s but when I drove it and punched it the g/s would go up to 880. That way higher than before??

80 g/s not 880.

Hi,

I suspect the MAF is failing. When you disconnect the MAF, the PCM is designed to default to a predetermined setting. I believe that is what you are seeing.

Let me know.

Joe