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4 Misfires on The Same Bank

25K views 11 replies 9 participants last post by  masantschi 
#1 ·
I have seen other threads where an engine will throw misfires, like 1-3-5-7 on the same bank without any code that might indicate a bad coil or injectors. If you have had this happen and were able to fix it let me know what you did, I am trying to help another one of our members. By the way, she has new plugs and wires along with 02's.
Thanks
 
#2 ·
With all the people who have had this and no one has a cause or fix to report?
 
#3 ·
Need to ask some more questions. I believe the issue was answered in the other thread.
Most likely an 02 sensor, or at least the connection fouled by oil.

Is there spark at the plugs? Coil packs are shared across the banks so I doubt that's the problem. If one plug wire was bad, I'd replace all.

4 spark plugs were replaced. Which ones? 1 3 5 7? They were 'bad' but what did they look like? If black, O2 sensor.

A broken rocker shaft would cause misfires on one bank, but it wouldn't go away and reappear minutes later, and there would also be considerable associated noise.

If we have spark at the right time and compression, then look at fuel. 02 sensors are the biggest culprit in that area, right?

Clean the sensors and swap sides.
 
#4 ·
Broken rocker shafts are usually silent, but permanent. It's amazing how well these trucks run on four cylinders!

There are very few components that can have an impact on only one bank. The very first place to look is oxygen sensors, but, while we're at it, when the plugs/wires were replaced, was the upper plenum removed, or did they have a four year-old girl do the wires with her tiny little hands? If so, we may want to look at the wiring of the injectors.

I recently had a client replace his plug wires and had some weird misfires, he'd swapped the IAC valve connector with the coil pack! His misfires were not confined to a single bank and not all of them either.

Oxygen sensors usually won't cause misfires as the EMS will recognize a bad input and go into limp home mode, not misfire mode.

Do we have compression numbers? Might show us the condition of the rocker shafts.

Lastly, did the problem occur immediately after replacing the plugs/wires, or did something else magic happen?
 
#5 ·
She said they were changing out plugs one at a time also. Why? And are they the same spark plug? Is her 02 sensor making adjustments the type other plugs don't like. What did the plugs look like? If they were covered in water? I assume the typical H.G. tests were done. Compression and rocker shaft sounded good
 
#6 ·
Thanks for the feed back. To keep this from being 3rd. hand I have copied her thread below with all the specifics. If anyone has any ideas, I will be talking to her tomorrow and would be glad to pass on any and all suggestions.

"Dear Land Rover Gurus,
This is my saga: 1 month ago my Disco II with 127,000 KM died. The Harmonic pulley had failed. Codes: P1590,PO300, P0303, P0134, P0135, P0155, P0304, P0308, P0150. After new pully installed all codes erased. Drove it 1 mile and returned to the shop.

Now error codes: P1590, P0135,P1300,P0301,303,305,307. They erased all codes, let it idle for 20 mins, the codes that returned are: P1590, P0307 P0135. Mechanic checked spark plugs (which were only 6 months old and at that time changed the wires too 8mm and O2 sensors front and back on the left side. There were 4 spark plugs that were bad, replaced those. They replaced 02 sensor the one that corresponds to P0135. Still P1590 (I know this is the 3 amigos and it doesn't worry me), however P0307 misfire still detected. Mechanic thinks maybe the wire for the 7th spark plug is faulty and suggests I change that one as well as put Ignition cleaning fluid in the gas

I go to pick up a wire for the 7th spark plug, the truck is really running rough now. They check the codes again. Now, all four O2 sensors 0150,0155, 0134 0135 and cylinders 1-7 showing misfire along with the 3 amigos P1590 and P1300.

Mechanic is stumped. He now thinks since the misfires of 1,3,5,7 are occurring that maybe it is the ignition/spark/induction coil on that side. Where I live there are no Land Rover mechanics, and my mechanic suggests I post on a forum where guys will know more than he. I don't know if he checked the fuse boxes to see if there are any faulty fuses and or corrosion. I live in the Dominican Republic.

I apologize for any words that are incorrect since I have a translation challenge where my mechanic is Russian and speaks no Spanish or English. He did work on Land Rovers a bit in Russia. The dealership in Santo Domingo is horrible. They couldn't even change the oil correctly and tried to stuff 9 litres of oil and didn't tighten things it was a horror show."
 
#7 ·
Mike, just walk through a checklist. I will certainly yield to PT regarding the 02 sensors, so my check list in order would be as follows.

1. check plug wire routing and seating. Since the wires were touched, that's the first place to start.

2. compression test to validate the rocker shafts.

3. retrace every where hands have been. I'm not sure if this is what PT meant by 'magic',
but I have lots of experience knocking something loose, breaking a connector or forgetting to plug something back in.

4. Without regard to Mr. Schram, I'd swap 02 sensors side to side but, only because I'm stubborn and probably missed something in step 3 ;-)
 
#8 ·
got to go with PT and csbd if you look at her original codes then as i said in the last thread they were all O2 sensor related and 2 missfires.
these are the original codes minus the amigos and missfires
P0134 Land Rover Lambda Sensor Upstream Catalyst, Bank 1 - Signal Missing
P0135 Land Rover Upstream Oxygen Sensor Heater Left Bank - Short/Open Circuit
P0155 Land Rover Upstream Oxygen Sensor Heater Right Bank - Short/Open Circuit
P0150 Land Rover O2 Circuit (Bank 2, Sensor 1)
I am removing the mkssfires as they were not the whole bank and probably related to the O2 codes.
Only once they started to change things did she loose the whole of the driver side bank. That means whatever happened, happened after the changes. that means go back and check everything. Once you start to get O2 sensor problems the ecu will often itself start to cause missfires in order to protect the catalytic converters and prevent then getting so hot you have under hood fires.
Double and triple check the connectors and the wiring
never lost a complete bank on the rover but I have seen it in the V8 jags and mercedes I work on and its more often than not the ecu trying to stop excess fuel getting pumped into the cats through poor or non existent signal from the O2 sensors. Seen some of the cats glowing cherry red trying to burn off extra fuel before the ecu starts to cut spark and only fire the injectors every third or 4th cycle.
cheers
Barri
 
#9 ·
Did anyone get a fix for this? I have the same problem with an 01 disco. codes of 1300, 0308, 04, 06, and 02. Not sure if it is a coincidence, but this started after my power steering pulley went flying due to loose bolts. Something belt driven thrown off maybe? Every couple of days it does this, get on the gas and it hesitates, CEL starts blinking, then it recovers and I'm on my way. Engine seems to shutter slightly when near idle speeds as well.
 
#10 ·
I have experenced this dtc nightmare myself.The final problem (which no error codes point to) ended up being a faulty connection at passenger side coil pack. On my 99 disco 2 two of the connections inside the the plug on the harness end(male plug)were broken. The second time was on my 99 range rover w/4.6. check your connections and the harness wiring from your coil pack back to your ecu.
 
#11 ·
Hey everyone. Im having a very similar problem. 2004 disco 2 with 69k miles on it. Had a shop replace coils, wires, plugs, cats, and all o2 Sensors. Truck ran great for about 100 miles. then it started missing really bad again. Now it barely runs. pulled the plugs, they were terribly black with carbon. replaced them. Getting Fuel, getting spark, but figured out the entire passenger side is not burning. After letting it run for 20 minutes, I can still rest my hand on the exhaust header. It barely runs and idles super low and shakes. Cant Drive it. Any thoughts?
 
#12 ·
What happened for you to have to replace all of that stuff? Why did they replace the coils?

Honestly, if it ran fine for literally '100' miles without any issues and now has multiple misfires on 1 bank, it sounds like one of the coils may be faulty and pooped out on you. You should take it back to the shop and have them fix it as I'm sure the work is under warranty?
 
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