So, about 100 miles ago, I replaced the head gasket on my 2002 disco II. Since then I have had multiple overheating problems leading to me changing the thermostat, water pump, pressure cap, and radiator. About a week ago, I was driving home from school and the engine service light came on. When I plugged in the OBDII, it gave me codes p1300, and codes for cylinders 2 and 4 misfiring and a multiple misfire code. I have since changed the cylinder 2 and 4 spark plugs and ignition wires, but to no avail. The check engine light flashes upon ignition. IDK what to try next.
Any advice would be awesome.
Thanks,
Bowman Blocker

 

i have the same issue except i get a cylinder 3 and 5 code.
I have replaced all the plugs and all the wires just to be complete
Any help would be great.

 

From my experiencing there really is no definitive solution to resolving all misfires. Too many things can cause engine misfires and for some reason with the Discovery 1/2 models, its too dam common. I installed a new block, radiator, thermostat, cooling hoses, ignition coils, spark plugs, ignition wires and even the fuel injectors and had the cylinder heads machined and o2 sensors replaced: STILL HAD MULTIPLE CYLINDER MISFIRES! I never got to the bottom of it. My mechanic was stumped and even Turner was at loose. So my advice to you folks is start with the basics and work your way up the ladder to the more complicated stuff.

Start by giving the truck a full tune up. Replace the spark plugs and ignition wires. Ensure plugs are set to correct gap. Check, double check and triple check that the wires are properly plugged in at the coils and fitted in correct order. Also make sure none of the wires are touching the hot exhaust manifolds. Next replace your o2 sensors. Bad sensors may influence air to fuel mixture in a negative way that coukd result in misfires. Next replace the ignition coils but dont go with the dirt cheap ones because they are such a pain in the butt to replace and you want to be sure quality is not an issue. If your still getting misfires ...... best of luck to ya because your in for one hell of a battle!

 

Can I resurrect this thread? I'm having multiple misfires on 1,3,5. I was having random misfires so I've replaced my coil packs, wires with magnacore 8mm, and plugs with Champion plugs gapped at .040. The Disco was doing fine for a while, but now it's a constant misfire right as I was going on a long trip. I had to swap vehicles. I feel like its lost power or acceleration. I've cleared the codes and it comes right back once I restart the vehicle and drive. I'm thinking maybe the catalytic converter on the drivers side maybe going bad, not sure how to test that. Would O2 sensors cause misfires? I've replaced the post-cat O2 sensors. I don't have any leaks. I've pretty much fixed all of the leaks. I know this is a frustrating topic from what I've read so far. Seems nobody has a real solution, it's hit or miss on the fixes.

 

Well, did a little testing. Pulled the number 3 cylinder spark plug to take a look at it. It looked like normal wear, so I reinstalled it. Cranked the car up cleared the codes and went for little drive. SES light started flashing again, so I looked at the codes. Cylinder 1 & 5 misfire, no misfire on cylinder 3. I'm going to pull the 1 & 5 spark plugs, check those and reinstall and see if the misfire clears on those cylinders as well. Very strange, any clues?

 

Went ahead and replaced all 8 spark plugs. Used Champion RC12YC. That might be my problem.. First set I'm going to say lasted about 20k miles. Went for a drive, no SES light and no codes. We'll see how it goes. May try a different brand of plug next.

 

Hello all, new to this site, sorry for long read but I need help. I have a 2010 range rover sport hse with about 156000kms. This morning, I was on a really bumpy ramp onto the highway. When it came time to switch lanes, I got the "restricted performance" code along with a serious drop in power. I could barely maintain highway speed. Car seems to run fine while at high speed, just not a lot of power. When I exited the highway, the engine was running rough at lower speed and while waiting at a red light the whole car was shaking and idling rough. Tried turning it off and back on, no change. Upon pulling into a parking spot at low speed, the car shut off on me. Put into park and restarted, was able to park but engine still running rough and feels like it wants to choke out. I hooked my scanner up and it is saying misfire in all cylinders, misfire detected on start-up and pressure line solenoid line 5 fault short circuit. Yesterday I filled up with mid fuel instead of premium, but that's the only change I've made. Tried unplugging battery and reconnecting and also added some octane booster to try and counter the mid fuel grade. Unplugged air flow sensors and plugged back in. Still no improvement. I'm wondering if anyone has had the same problem and knows the fix? Thanks.

 

Found the issue, the dreaded timing chain. Recieved the parts today for $1000 usd and installing them this weekend.