Been having trouble with some intermittent codes and recurring misfire.


I drive 42 miles to work every day. The first 10, and the last ten, are stop and go, under 60.


The middle 22 miles is Turnpike.


Disco runs fine around town. get on the Turnpike, drive my 22 miles and exit. As I leave the Turnpike and start the stop and go, I occasionally feel a misfire. Within a minute or so, the SES light goes on. After driving for a bit, the misfire goes away. After a couple days, the SES light goes off. A couple days later, it happens again. Always exactly the same. Literally within the exact same stretch of road, shortly after leaving the Turnpike.


Last week it got really bad. Felt like it was missing on more than one cylinder, and stayed that way all the way home from the TPKE.


Parked the Truck for a week before I got a chance to take a look at it.


Hooked up the code reader. Pulled the codes and the started it up. It ran fine, no misfire. Cleared the codes and nothing came back. SES light is out.


Codes were for misfire on cylinders 2 and 3, and bank one upstream O2.


Any ideas what would cause a misfire that only occurs after a long highway drive, and then ultimately goes away?


Thanks.

 

Bumping this in case it was missed.


Anyone else ever have this kind of strange inconsistent recurring misfire.

 

when was the last time you had a tuneup? Gas probably? Some codes disapears when conditon goes back to normal.

 

wondering about plug wires maybe shorting out?
Also curious about last tune up

 

Without codes it will be difficult to determine where to start. Im no mechanic but i am maintaining 2 discos. I can suggest if you dont have the codes, start from the beginning. IN to OUT. Get a MAF cleaner. Spray the sensor vigorously almost like wet. Let it dry completely.
Tune up in an LR shop cost over 500 bucks. You can upgrade your cable to Magnecor wire and will cost you less. And since you have to get to the coils, better replace it too. Then plugs.
But you can skip the 2nd. Get front O2 sensors. Youll be done. But check all the vccum hoses that they are fitted well. Some of them can be pulled easily. You can use small plastic ties to secure them from the small plastic fittings.
Start engine, warm it up properly and rev it near your uncomfortable limit to clear out debris and what not in the system. Cheers!

 

Wires are magnecor, coils are three years old, replaced at the same time as the wires. I'm going to try new plugs today and see what that does.

 

label the plugs as you take them out and youtube learning about plug condition, that if you dont know.

 

Resurrecting this thread because the condition is still there and I have an additional question.


Can a faulty O2 sensor cause a misfire code. I've read that a faulty O2 senor can cause a lean condition as the ECU drops pulsations in the injectors on that bank.


Does this make sense?


Another thing. All of my misfire codes are on the same coil. I have had codes 0302, 0303, 0305 and 0308. No codes from the cylinders on the other coil.


To this point I've replaced the plugs and wires, and the coils are about three years old. Engine runs very strong about 95% of the time. Usually stumbles when I first start it up, or after a long dive. Has anyone ever had a coil cut out intermittently?


Just looking for some suggestions. It seems strange that I'm only getting misfire codes from cylinders 1, 2, 5 and 8. I'm thinking that the coil could be bad, but I don't want to rip it apart if that's not it.

 

You cold just swap the coils. If problem follows ripping apart the second time should be a breeze.

......

 

This sounds like what mine was doing. I changed the plugs and wires to Magnecore. Still had misfire codes and rough idle. Especially when the computer went to closed loop.

Changed the front O2 sensors and runs smooth and perfect.

Got OEM Bosch from Rock Auto for way cheaper than other vendors.

I suggest changing O2 sensors.