Hello all,

Can someone assist me please. I am having misfires on Cylinder 2, 4, 6, & 8. This ithe whole driver side. Does anyone know what could possible be causing this? I have been googling? I have put fuel cleaner in, but that was just today. I had someone scan the modules earlier and there were errors they cleared them but by the time I got to the house, CEL was on again. That is when I had the 2,4,6,8 misfires. Yesterday it was just 4 & 6. It really acts up after I stopped car after driving go in store and then restart it shakes / misses and then eventually evens out... till I stop and restart again.

I looked at tip of plugs for 4 & 6, they were kinda a rusty color verses plug 2 tip was still kinda white. That is when number 2 wasn’t misfiring.

 

May be a damaged cat conv.

 

Would I get o2 sensor errors? I could have the Cat changed but don’t wanna do that if that is not the problem. Is there anything else I can check? Would a battery cause this issue maybe?

 

I had same bank 2 problem with misfire's.
Changed plugs..still misfire's
Changed coil pack's ..still misfire's

Found out i was only running on one fuel pump (4.0l 2001 XKR has two pumps)
Changed both fuel pumps and now have no misfires on bank 2.(dont know why i only got misfire's on bank 2 and not bank 1 with bad pumps)
So worth checking out you have good fuel delivery...

Be careful,if your mil/cell light flashes when misfire's happen you will damage the cat.

 

It does not flash. It just flags the misfires after the engine has cycled a few times. This appears to happen once car has ran and warmed up. I drive to maybe a store get it hot, get out and once it sits just for a little bit, I go back out and start it then it runs rough upon start up. Then it will eventually even out,

There was a few u codes before it got cleared.

I do remember the guy said something about the fuel having a stored code. Today went to the store and radio wouldn’t say anything. I tried turning it off and then it wouldn’t power back on till I cycled the key again. Do you think a battery may cause the misfires. I think when I checked my battery it was around 11. Something

P1235

 

The battery is very low at 11.Something (its under 25% ) Dont know how it has the power to start the car.

Get it charged up or get a new battery (it may well be your problem)
Think the P1235 is the fuel pump control out of range.

If you have a fuel pressure gauge, have a look at the fuel pressure when it is running rough and see if the psi changes as it eventually evens out.

 

Thanks for all the replies.

I checked yesterday after car was shut off for a few minutes and batter showed 12 volts.

What should the fuel pressure be when the car is at idle? And after it is shut off?

Does this car have 2 fuel pump?

 

Your battery is still very low at 12v needs to be 12.4 or above

12.6 = 100% charged
12.4 = 75% charged
12.2 = 50% charged
12.0 = 25% charged

You have 2 fuel pumps..
each rated at 170 l/h at 55.11 psi to provide a combined flow/pressure of 180 l/h at 69.61 psi.

Im not that familiar with your none return fuel system but at idle i would think you should have 60-70 psi (if im wrong may be some one can correct this).
after you turn ignition off the psi should hold but will gradually come down over time (the psi should not drop quickly)

I think you need to try a new battery..

 

Thank you XKR, I will try to get a better battery and see if that will work. I thought with the system charging and being a 13 something would be fine, but maybe not.

 

Yesterday, I moved the 4th and 6th coil over to the RH side. The misfires were then 2,4, 6, and 8. I cleared them and then it went back to just 4 and 6. I am praying that I don't have a gasket leak. I tried to start it 2 times yesterday and it turned over and stopped as if something was preventing it from turning. I waited and then tried again, and it turned over and started. I am hoping that water is not going into those 2 cylinders.

I used my thermo tool and checked heat on the cats. The right side was 380 ish and the driver side was 202??? If the driver side was clogged, wouldn't it be much hotter? I am going to try and check fuel pressure today.

 

GLORY TO GOD!!! He showed me the problem. Water is what's causing the misfires. Apparently pressure is getting to high in the Radiator hoses and after car sits, the water pushes into the cylinders. I felt the pressure on the hoses felt too tight. Thanks everyone for your assistance.

 

When you have had the head gasket fixed, Do your self (and the car) a favour and replace your battery..
Good luck.