DIR Return Create A Forum - Home
---------------------------------------------------------
Old Leafsprung Land Rovers
HTML https://ollr.createaforum.com
---------------------------------------------------------
*****************************************************
DIR Return to: Technical tips & Questions
*****************************************************
#Post#: 31167--------------------------------------------------
Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: inglishg
Date: July 16, 2012, 3:04 pm
---------------------------------------------------------
Can anyone shed any light on this one?
Last night, all fine. Purring along as usual. Filled up with
petrol and came home.
This evening...tiz a bag o'shite.
The engine seemed underpowered (yeah, honest!) and applying
throttle created a horendous knocking - sounded like the big
ends were totally shot.
I coaxed The Shed back home, and started to investigate.
The engine starts fine, but a little lumpy. Reving it creates
the deafening knocking noise.
Individually I removed each HT lead and found that 3 & 4 made
barely any difference at all. Either 1 or 2 stalled the engine.
I swapped various HT leads thinking I would transfer the
problem. No. 3 and 4 still didn't affect the engine running (ok,
there was the slightest "ticking" noise from the engine that
became audible then either HT lead was removed from the plug
whilst running).
I then removed the spark plugs individually, started up and
viewed the spark. 3 and 4 were sparking - as were 1 and 2 of
course.
Lifting the dizzy cap showed a nice clean set of terminals. The
dizzy cap is obviously quite recent.
I've blasted all the leads and OUTSIDE of the dizzy cap with
WD40 with no improvement and I'm now at a loss.
I wondered if there were stuck open valves on cylinders 3 & 4,
so I removed the rocker cover and viewed the rockers all
behaving nicely with the engine running.
What am I missing? It's got to be something simple. Twaz running
so smoothly last night. Why should "whatever it is" only affect
3 and 4???
Help!!
#Post#: 31168--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: Goose
Date: July 16, 2012, 3:08 pm
---------------------------------------------------------
Sounds like a head gasket blown between cylinders 3 and 4.
Better get the spanners out! :-\
#Post#: 31174--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: inglishg
Date: July 16, 2012, 3:17 pm
---------------------------------------------------------
Yeah? That's serious!!!
Thought it would be a simple electrical problem. Over the past
few days, the bonet has been up a fair bit whilst all the
preparations have been carried out for the painting, and
occasionally ( ::) ) it has rained.
I'm really sad now :(
#Post#: 31180--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: Goose
Date: July 16, 2012, 3:23 pm
---------------------------------------------------------
A compression test will confirm if it is or not. Have you got a
compression tester, if not it's a useful tool to own.
#Post#: 31186--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: inglishg
Date: July 16, 2012, 3:30 pm
---------------------------------------------------------
Ah...yeah, I've got one of them.
Not used it for years and years and years...(diesel Landy's and
company cars ain't needed 'em!)
I'll give it a go later this week.
Still hoping it'll mysteriously fix itself overnight...
#Post#: 31189--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: Roveerman
Date: July 16, 2012, 3:36 pm
---------------------------------------------------------
What colour where the plugs? If they were different shade to
plugs in 1,2 this will show the state of the burn in the
cylinders. As above a compression test will give a fuller clue
as to the state of the engine.
If the test shows even pressure it could be the plugs failing, a
friend dropped a plug by accident and then fitted it, the engine
was a bag of spanners till a new one was fitted.
#Post#: 31190--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: guest13
Date: July 16, 2012, 3:43 pm
---------------------------------------------------------
even if it is the head gasket, its only a few hrs and 20mpg
pounds ish to sort.
#Post#: 31193--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: inglishg
Date: July 16, 2012, 3:49 pm
---------------------------------------------------------
The plugs were all consistently a "biscuit brown" colour. They
were all dry - perhaps No3 was slightly wet, but is was next to
nothing.
I'll carry out the compression test later in the week and look
at getting some replacement plugs.
Please, please be an easy fix :confused:
#Post#: 31207--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: Hairyvike
Date: July 16, 2012, 4:10 pm
---------------------------------------------------------
....also check that there's no tracking on the inside of the
dizzy cap between 3 and 4......even "new" stuff can crack
occasionally...
#Post#: 31210--------------------------------------------------
Re: Misfiring on cylinders 3 AND 4 (2.25P)
DIR By: inglishg
Date: July 16, 2012, 4:33 pm
---------------------------------------------------------
Should I have given the inside of the dizzy cap a blast with
WD40? I didn't, coz I recall it should be kept dry.
Looks like there's a fair bit I haven't checked yet before
condeming the head gasket...he said hopefully!
*****************************************************
Page 1 of 4
DIR Next Page