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

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

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

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

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

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.

Hi,

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

Take care,

Joe

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

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

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.