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#Post#: 96437--------------------------------------------------
Ignition timing issues 2.25 petrol
DIR By: ProDave
Date: March 2, 2015, 11:32 am
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My motor has never run perfectly. ever since I got her, she's
been prone to an occasional misfire at high revs. also when
changing gear, clutch out and power on, she always coughs and
splutters before picking up.
This has got progressively worse so time to have a look.
First thing, contact breaker pitted as fuck, so fit a new one
expecting that to fix my problem. New contact breaker, correct
gap set, she hardly starts. WTF?
Check static timing, out by a country mile. Now she starts and
idles, but misfire and lack of power at high revs worse than
ever.
I've been playing with the timing "trial and error" and have got
to a point where it's vastly better but still not right.
I guess I have to buy me a timing strobe to set it up properly,
or do you think there's something else wrong and I'm chasing the
wrong fault?
#Post#: 96442--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: blackskidmarks
Date: March 2, 2015, 2:55 pm
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Could be a weak spark failing as load increases, or a weak
mixture as fuel to air ratio changes.
Is coil starting to fail? Swap with a mates to test.
Are HT leads good? Sparking plugs too old?
Carb clean inside?
Good luck.
#Post#: 96443--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: Peter de Dawg
Date: March 2, 2015, 3:33 pm
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Strobe light..Nah...I've found if you set a Land Rover with one
of those gay little strobe things it will run like shit, and
you'll need to give it a good substantial tweak "by ear' untill
it sounds OK,
in fact the 'by ear' method always works for me as a final
adjustment
#Post#: 96448--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: ProDave
Date: March 2, 2015, 4:44 pm
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If it was weak mixture it would normally run hot. Temperature is
just fine, half way up the gauge where it always has been.
Plugs all look good and the right colour indicating a good burn.
Not tried swapping the coil that's a good thing to try. Dizzy
cap and rotor arm look good as to HT leads.
I was surprised just how far I can turn the dizzy without making
any difference at tickover. It's was only by turning it a bit
then going for a blast up the road that I could tell what was
"best".
The current setting she's not bad at low revs, but runs out pf
puff and starts missing at higher revs.
To be honest I have been wondering if I have a carb / fuel
problem. That tendancy to die and cough a bit when you first put
your foot down sounds more like a fuel problem than an ignition
problem? though oddly at the current timing setting it's not so
bad. But fiddling with carb mixtures is something I know
nothing about. someone's going to ask what carb it has next and
the answer is without going and looking I don't have a clue,
other than it looks very basic.
#Post#: 96449--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: Jackual
Date: March 2, 2015, 6:21 pm
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Misfiring at high revs you say?, Swap the capacitor in the
distributor for a new one.
#Post#: 96450--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: Parn
Date: March 2, 2015, 11:20 pm
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Hi Dave
I had a similar problem not long ago.
Turned out to be fuel vaporisation.
If all else fails re-route the fuel line away from anything that
gets warm.
Good luck
Alan
#Post#: 96452--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: divie
Date: March 3, 2015, 1:13 pm
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Have you checked the vacuum advance on the dizzy ? Take the pipe
off at manifold end and suck to see if revs pick up. If not
advance mechanism may be stuck or diaphram fucked.
Given that most electrical issues are fuel and vice/versa check
for air leaks on the inlet. Try spraying WD 40 around carb
base/inlet manifold when running to see if revs pick up.
#Post#: 96572--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: DarrenH
Date: March 11, 2015, 7:39 am
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points "pitted to fck" plus rough running with new ones, sounds
like condenser issue to me.
vac advance is only really a benefit for part throttle cruising
(gives you a tad more advance when engine isnt loaded, for fuel
economy) youd miss is, sure, but it wouldnt cause rough running
#Post#: 96622--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: ProDave
Date: March 13, 2015, 11:50 am
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I think my parts replacement schedule will be condensor, if that
fails try a new coil. then start looking at the fuel pump.
I am going to borrow a timing light and a colourtune (remember
them?)
One other thing, speaking to a local guy about this he asked
what carb I have. It's a Zenith. He said they are a pile of
shit and prone to clogging up when the vehicle isn't used much,
so should I be looking at that?
#Post#: 96655--------------------------------------------------
Re: Ignition timing issues 2.25 petrol
DIR By: seriesewan
Date: March 16, 2015, 11:09 am
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swift warning regarding new condensors... the quality in new
parts ( regardless of brand ) seems to be awful. after getting
through 3 new condensors ( different brands ) i ended up cutting
my losses & going electronic ignition... This is by a country
mile the best modification to the engine i have made
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