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Hi Rev Misfire as in past 6k
Posted: Fri Aug 29, 2008 12:06 am
by Coops
Bit of a confusing problem,
on the rollers saturday the car was hitting well over 6-6.5k no probs at all.
didnt abuse car on way hoem and parked it up.
got car out yesterday, took for run, and now when it gets to just over 6k it holds back as if its on a rev limiter,
the limiter was set on 7.5k now set at 9 still does it,
have a new set of plugs and cap, no rotor arm as that was new a while back but may change it,
any ideas what it could be???
up to this missfire the car revs and pulls like a train every time. then plays up when it gets to just over 6k.
Unilite playing? cdi unit? leads? coil?
all advice welcome.
Posted: Fri Aug 29, 2008 7:03 am
by Ian Anderson
Bad fuel?
Perhaps a blockage in the pipe / dirty filter
Ian
Posted: Fri Aug 29, 2008 8:33 am
by IanT
Different plug gaps?
Where did I read somewhere recently about RV8 high rev misfires & plug gaps ??
Found it:
http://www.v8forum.co.uk/forum/viewtopi ... +plug+gaps
Posted: Fri Aug 29, 2008 12:28 pm
by ian.stewart
I had aplug missfire problem, turned out to be the wrong gap, closed the gap to 33tho, and the problem went away
Posted: Fri Aug 29, 2008 4:25 pm
by katanaman
ECU logs should tell you a bit. If it shows the misfire then its the unilite or cdi depending where you take your trigger from. Might even show something in the fuel itself you never know.
Posted: Sun Aug 31, 2008 3:53 pm
by Rossco
I would opt for new plugs.
Doubt if it's the CDi. You've got the 685 and that's a beast of a unit well capable of more than you've given it.
Posted: Sun Aug 31, 2008 8:03 pm
by Coops
Marki,
a log of it is here, you can see the missfire as i held it foot to the floor to try and get a reading on the log while accelerating,
http://www.v8forum.co.uk/zip/newdatalog.zip
Posted: Sun Aug 31, 2008 8:33 pm
by katanaman
yes can see it alright but its raged more than spiked so I wouldn't say its your dizzy or cdi. probably just a plug misfire like others say. Maybe someone else can have a look and see if they agree?
Posted: Sun Aug 31, 2008 8:54 pm
by Coops
i started to fit a new set of plugs and cap before my holiday, so not had chance to test it yet.
Allan, did you get my email before i went on holiday friday regarding some mallory spares mate???
Posted: Sun Aug 31, 2008 9:14 pm
by Rossco
Tony
I'll have a look and see what I have but I'm fairly sure I've only got caps left.
If you want a new one I'll bung it in the post tomorrow.
Posted: Sun Aug 31, 2008 9:20 pm
by Rossco
Rossco wrote:Tony
I'll have a look and see what I have but I'm fairly sure I've only got caps left.
If you want a new one I'll bung it in the post tomorrow.
Also looking at that log I think you've got a slight vacuum leak somewhere.
Posted: Sun Aug 31, 2008 9:21 pm
by Coops
well the plenum is off at the mo as checking the pushrod locking bolts to make sure they are still tight,
will then reseal the plenum,
Posted: Sun Aug 31, 2008 9:25 pm
by Rossco
Do you want a new cap?
Freebie for you of course
Posted: Sun Aug 31, 2008 9:48 pm
by Coops
cheers mate,
that would be spot on
just hoping it's not the rotor arm,
as can't remember who i got my last one from,
may of been you on ebay thinking about it
Posted: Thu Sep 04, 2008 9:57 pm
by Coops
right managed to get hold of another mallory cap today after work,
and a fitted the new plugs,
bolted all back together fired her up, sweet as all ways, took out on the road and ran as normal, until you let rip, as soon as you nail it to the floor and get near 6k the same miss fire is still there,
anything else?
coil?
leads??
dizzy?
starting to loose it with the car
