1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Welcome To LandyZone!

    LandyZone is the biggest Land Rover forum on the net. We have plenty of very knowledgable members so if you have any questions about your Land Rover or just want to connect with other Landy owners, you're in the right place.

    Registering is free and easy just click here, we hope to see you on the forums soon!

Misfire Coil or Plug...

Discussion in 'Range Rover' started by Doo, Feb 12, 2020.

< Previous Thread | Next Thread >
  1. Doo

    Doo Well-Known Member

    Joined:
    Jun 2, 2016
    Posts:
    3,739
    Likes Received:
    2,109
    Location:
    City of a thousand clowns...
    I've lost the will to live with this damn car :(

    I just want to fix it and sell it now....

    New fueling ECU coded and working and STILL the computer showing a MAF fault. The grotty plug is working, the ECU may or may not have been faulty. But the MAF fault showed with 2 different new Bosch MAF's, a different ECU and the MAF connected or not. I don't understand :rolleyes:

    My next move is check the wires for load resistance. Plug a 55 watt bulb in to each different part of the plug and see if the bulb suddenly goes out o_O

    Is it possible some fucking twat from Stirling (the cowboy shit for brains who installed the LPG) have created an issue?? Because SOMETHING is causing the "NO MAF" problem on the code reader...

    And added to that, It showed a misfire on plug no3 before and after the re-code of the "new" ECU! I pulled the plug & find it wet with petrol, so swap it for a £10 new plug..... Same issue :confused: Now I know what you're thinking, but the misfire is identical on petrol AND LPG, so defo seems to be electrical as opposed to say, an injector issue o_O

    So, after swapping the spark plug for a new one, I get the exact same problem! Misfire plug 3.

    I use those thingies you pop onto the end of the plug, then the lead plugs onto that and the thingy lights up each time there is a spark. I thought the coil was bad, but the plug lit up perfectly. I changed the plug and still the same problem, the thingy shows perfect spark, but the engine sounds like it's firing on five cylinders :eek:

    So my thoughts are leaning towards a blocked cat... Could that be the issue? I know the car will run with a cylinder off, hell it ran with three leads chewed through by mice when I first bought it o_O But it sounds awful, so that's the only thing I can think of. I'll check the whole bank for wet plugs to see if it confirms my suspicions.

    I mean, for the car to run so shite while getting sparks, air and fuel is a new thing. She's always ran so well before.

    And I need to get to the bottom of the MAF problem an orl :rolleyes:

    *Googles Volvo XC60 and Toyota Land Cruiser * o_Oo_Oo_Oo_Oo_O
     
    Grrrrrr likes this.
  2. Grrrrrr

    Grrrrrr Technician, Bodgit & Scarper Ltd

    Joined:
    Jul 8, 2012
    Posts:
    14,094
    Likes Received:
    3,884
    Location:
    Buckinghamshire, UK. ('95 DT)
    Sounds plausible. Try taking the cats off and see if it runs better. I am still angling towards wiring though, an internal break somewhere.
     
  3. Grrrrrr

    Grrrrrr Technician, Bodgit & Scarper Ltd

    Joined:
    Jul 8, 2012
    Posts:
    14,094
    Likes Received:
    3,884
    Location:
    Buckinghamshire, UK. ('95 DT)
    Do you have noid lights? See when injector is open? I just wonder if it is jammed open? That would kill the MAF sensor, wouldn't it?
     
  4. Grrrrrr

    Grrrrrr Technician, Bodgit & Scarper Ltd

    Joined:
    Jul 8, 2012
    Posts:
    14,094
    Likes Received:
    3,884
    Location:
    Buckinghamshire, UK. ('95 DT)
    LPG piggy backs off injector wiring? So if when they spliced in they shorted #3 out could they constantly hold an injector open?
     
  5. kermit_rr

    kermit_rr Well-Known Member

    Joined:
    Dec 9, 2018
    Posts:
    8,144
    Likes Received:
    5,419
    Location:
    North Shropshire
    Have you got good compression on number 3?
    I've an old lpg system on mine which means the injector signal goes thru the lpg ecu. If i unplug it the petrol side won't run
    I had a wet plug and a good spark, that turned out to be a worn cam
     
    Grrrrrr likes this.
  6. Grrrrrr

    Grrrrrr Technician, Bodgit & Scarper Ltd

    Joined:
    Jul 8, 2012
    Posts:
    14,094
    Likes Received:
    3,884
    Location:
    Buckinghamshire, UK. ('95 DT)
    I've a vague memory his engine is an almost new replacement?
     
  7. Colthebrummie

    Colthebrummie Well-Known Member

    Joined:
    Jan 24, 2017
    Posts:
    6,504
    Likes Received:
    6,046
    Location:
    Thatcham
    The LPG on my old Kia sorrento poisoned the oxygen sensors in my cat. Even when the sensors were replaced, the new ones only lasted a few weeks. No-one ever seemed to be able to cure the problem. This another reason why I don't like LPG.

    Col
     
  8. kermit_rr

    kermit_rr Well-Known Member

    Joined:
    Dec 9, 2018
    Posts:
    8,144
    Likes Received:
    5,419
    Location:
    North Shropshire
    Never heard of that issue before!
    Contamination in the lpg tank?
     
  9. Datatek

    Datatek Well-Known Member

    Joined:
    Feb 5, 2009
    Posts:
    36,896
    Likes Received:
    3,879
    Location:
    Near Poitiers SW France
    How would a jammed injector affect the MAF which is way up stream.
     
    kermit_rr likes this.
  10. dubbleRR

    dubbleRR Well-Known Member

    Joined:
    Mar 13, 2011
    Posts:
    485
    Likes Received:
    130
    Location:
    highlands of Scotland
    The plug might be sparking ,but is it the right firing order leads the right way round ,,,,other thing compression bad valves.....Is the plug wet with fuel or oil ,cause thats bad rings,, back pressure in crankcase ,or dare i say water from head gasket:eek: .......But if your getting rid i want first shout on yer roof bars :rolleyes:...:D
     
    RangeRoller dt likes this.
  11. Doo

    Doo Well-Known Member

    Joined:
    Jun 2, 2016
    Posts:
    3,739
    Likes Received:
    2,109
    Location:
    City of a thousand clowns...
    MAF has always been an issue on this car, I assumed its been running a base map.

    Plug wet with petrol. It was plugged into a £10,000 code reader which categorically stated all sensors within parameters Inc the O2 sensors. The left bank read slightly higher, but within acceptable limits .

    I have tested the MAF wires and got 3x + signal (2x 12v and 1x 5v) and two negative feedback (one probe to battery + and the other to the MAF plug .

    I stripped the wiring right back from the MAF plug to the ECU, which was how I discovered the grotty connection (but not sure it was related to the MAF issue). All wires seemed to be intact and no cuts or short circuits.

    The plugs have covered around 3k. The leads are recent Magnecor with numbers on each lead so you'd need to be a real muppet to get them wrong :eek:

    One did come loose at the coil which is why the plug was wet and I think it upset the fueling. But it's never run this bad or lacked power like this. So I'm off to put on my big boy pants (thermal boiler suit) remove the cats and knock the shit out of them o_O

    And yes Grrrrr, the engine has only just turned 20k miles. It's had 4 oil changes in that time (4yrs) so I wouldn't expect the cams to have worn away :confused:

    I will report my findings of course :cool:
     
    Grrrrrr likes this.
  12. Henry_b

    Henry_b SPARES OR REPAIR

    Joined:
    Jan 29, 2018
    Posts:
    11,878
    Likes Received:
    10,460
    Location:
    Hereford****e
    Multi point LPG systems piggy back off of the petrol injection for timing and quantity of fuel

    so if there is a fault with the pez side it will show on both fuels.
     
  13. dubbleRR

    dubbleRR Well-Known Member

    Joined:
    Mar 13, 2011
    Posts:
    485
    Likes Received:
    130
    Location:
    highlands of Scotland
    A bit a crap on the end of the cps ,can cause misfires ....had that in the past ;)
     
  14. Grrrrrr

    Grrrrrr Technician, Bodgit & Scarper Ltd

    Joined:
    Jul 8, 2012
    Posts:
    14,094
    Likes Received:
    3,884
    Location:
    Buckinghamshire, UK. ('95 DT)
    Sorry, thinking of o2. Seem to be jumbling words up recently.
     
  15. Doo

    Doo Well-Known Member

    Joined:
    Jun 2, 2016
    Posts:
    3,739
    Likes Received:
    2,109
    Location:
    City of a thousand clowns...
    I was speaking with the local 4x4 guru and he triggered a recent memory whereupon I was driving home and the car was running poorly and got steadily worse on LPG, so I switched to petrol and although it was slightly better, it wasn't by much. But I distinctly recall a heavy smell of burning (hot exhaust smell) and when I stopped & it cooled down, the ticking was pretty loud. Added to that, the smell of sulphur was rank. Added to that as well, I discovered the temp sensor had been loose & likely for a while...

    I rather think the cats are ex cats, they have voted for exit o_O

    The pipes are black and sooty on the downside, but peeking into the other end, they looked white. Think I found my answer :confused:
     
    Grrrrrr likes this.
  16. DanClarke

    DanClarke Well-Known Member

    Joined:
    Mar 13, 2009
    Posts:
    6,527
    Likes Received:
    10,309
    Location:
    Benfleet, Essex
    Ouch! That's an expensive fix I fear @Doo . But, if you have located the source of the problem, it is a 1-off cost to remedy for good and all and happy motoring is back on the menu.
     
  17. Grrrrrr

    Grrrrrr Technician, Bodgit & Scarper Ltd

    Joined:
    Jul 8, 2012
    Posts:
    14,094
    Likes Received:
    3,884
    Location:
    Buckinghamshire, UK. ('95 DT)
    Length of pipe and a hammer?
     
    RangeRoller dt and Doo like this.
  18. Doo

    Doo Well-Known Member

    Joined:
    Jun 2, 2016
    Posts:
    3,739
    Likes Received:
    2,109
    Location:
    City of a thousand clowns...
    Got a loan of a code reader and did my own investigation. I did it cold, engine off and outside temp at exactly 0 degrees Celcius.

    So after replacing the ECU and fixing the grotty plug, I think the MAF itself is buggered which is somewhat maddening as it cost £170 a couple of years ago o_O Everything changed after I cleaned the plug and replaced the ECU as in, it went mental, probably going by the temp reading it went super enrich....

    Anyway, check out the air temp :eek: My MAF thinks it's in the feckin Antarctic :rolleyes:

    [​IMG]
     
  19. Datatek

    Datatek Well-Known Member

    Joined:
    Feb 5, 2009
    Posts:
    36,896
    Likes Received:
    3,879
    Location:
    Near Poitiers SW France
    -39.5 is a default temperature which means that there is no signal from the temperature sensor
     
    Grrrrrr and kermit_rr like this.
  20. Doo

    Doo Well-Known Member

    Joined:
    Jun 2, 2016
    Posts:
    3,739
    Likes Received:
    2,109
    Location:
    City of a thousand clowns...
    So does that mean it could "still" be a wiring issue? o_O or perhaps the MAF is actually gubbed?

    I won't know until later. Just finished the cats. Need to put them back on along with the new exhaust system :cool:

    No cats, not middle box, only rear boxes. Next time my cunty neighbours cunty dog barks it's chops off at me it's going to get 125dB of V8 up its hole :D
     
    tomcat59alan likes this.
< Previous Thread | Next Thread >