Remembering that this engine ran completely fine in another car, I would be
looking at the manifold/carby end and of course all the hoses that connect
it all together.
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Richard Clough
Sent: Monday, 30 April 2001 22:00
To: [EMAIL PROTECTED]
Subject: Re: The "Datsun Miss"
Your description suggests the miss is not on each cycle so it's possible
that your ignition system has a fault, but I would look at the following
first as your vac/econo gauge is a clue to something wrong with the fuel/air
ratio. The econo gauge is a measure of manifold vacuum. It is showing that
vacuum is not contant at idle. This means that you could have a leak in the
inlet system, or head gasket leak or perhaps a valve sealing or ring/piston
problem.
Do a compression test on each cylinder next to see if they are all similar,
or if there are significant differences. If there are big differences, look
inside the head for the answer. If cylinder pressures are even, look
carefully at the inlet manifold e.g check its bolted up tightly, and at all
attachments that supply air or carry and use manifold vacuum, to check for
leaks.
----- Original Message -----
From: "Paul W. J. Stanley" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, 30 April 2001 21:54 PM
Subject: Re: The "Datsun Miss"
> Thanks guys there are a few things you mentioned there that I havent
looked
> at. Terry, it's not a miss every cycle, but it's quite regular like 1 to 2
> times per second. The exhaust is broken and it makes a loud rattle
evrytime
> so I know when it's missing (handy for almost deaf people like me). I
havent
> tested compression. The coolant does have a film of something on the
surface
> but it's not getting into the oil AFAIK that would cause the oil to turn
> into "snot". I could very well be air getting into the manifold, the motor
> is out of a newer 200B and it ran beautifully in that car.
>
> The eccono-gauge ;-) reads fairly smooth when it's doing about 1500 RPM
but
> at 850 RPM idle (that I was able to set myself) the needle is jumping all
> over the place in the 'idle' section of the gauge
> So should I rip the brake booster off and plug it up and same with the
> vacuum line (to test it?) . I think I will try that tomorrow if I can find
> the ignition key to it...I lost it :(
>
>
> Rick, by condensor you mean the thing in the dizzy? I put in a electronic
> one, and I didn't recall seeing a condensor. The wierd thing is the miss
is
> exactly the same as with the old dizzy with burnt out points and the new
> electronic one. So I am wondering whether is is electrical at all, since
you
> guys have mentioned mostly anything BUT electric.
>
> There was also a capacity on the coil, is that to filter out interference
> from the radio? I wouldn't know I ripped the radio out and replaced it
with
> 4 gauges and a LED voltmetre (ooo sports dash ;-)
>
> Another thing Terry, I turned the crank to 0 degrees and the rotor was
> pointing to the firewall drivers side...and cylinder 1 is the firewall
> cylinder. I tried it set to the standard Datsun way with cylinder 1 at the
> radiator, and passenger headlight on the dizzy, and then 1-3-4-2
> anticlockwise on the dizzy (my friend also told me to do it this way) and
it
> didnt start, just backfired. Has someone rebuilt this motor to non-Datsun
> standards?
>
>
> ----- Original Message -----
> From: FJ MAN <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Monday, April 30, 2001 5:39 PM
> Subject: RE: The "Datsun Miss"
>
>
> > Dont suppose you used the same vacuum advance line each time?
> > Coz if there's a hole in it you may end up with symptons like yours. I
had
> > the same problem with my 180b recently and replaced coils plugs many
times
> > leads etc all parts then saw a tiny hole in my vac adv line. Doh ah
well
> > might help ya
> >
> >
> > >From: "Terry Rudd" <[EMAIL PROTECTED]>
> > >Reply-To: [EMAIL PROTECTED]
> > >To: <[EMAIL PROTECTED]>
> > >Subject: RE: The "Datsun Miss"
> > >Date: Sun, 29 Apr 2001 23:21:59 +1000
> > >
> > >Paul,
> > >
> > >Have you done a compression test or tested for a leaking head gasket
> (leak
> > >down) or are you losing water. You say it's a regular single miss so I
> > >take
> > >this to mean that it's missing on every cycle or there about. If this
is
> > >the
> > >case then the cause should be east enough to find as you only need
three
> > >things to fire; i.e. compression, correct fuel/air mixture and strong
> > >regular spark so check it all out.
> > >
> > >#1 cylinder on a north/south engine is closest to the radiator and also
> the
> > >lead is the one pointing towards the passenger side headlight. The
> cylinder
> > >you have described and also the dizzy position is #4. The timing on a 4
> > >cylinder 4 cycle engine is the same for #1 and #4, only the
> camshaft/valve
> > >position when either piston is at TDC determines the difference between
> the
> > >compression and the exhaust stroke.
> > >
> > >LRP petrol will not cause misfiring by itself, granted the plugs do get
a
> > >little dirtier than when run on super but ulp & pulp petrol burns much
> the
> > >same as LRP (it is pulp with a lead replacement additive) so you wont
get
> a
> > >steely grey exhaust burn anymore, rather blackish in colour and the
plugs
> > >seem to burn with a reddish tinge which I suspect is the additive. If
you
> > >suspect it's something to do with LRP, may be worth sticking a tank of
> > >optimax through it and see what happens. Check that the carbie, the
many
> > >vac
> > >lines attached to the stock carbie or the manifold are not leaking
> vacuum,
> > >also check your booster valve is working correctly.
> > >
> > >have fun, hopefully it's something simple to rectify,
> > >
> > >regards
> > >Terry
> > > -----Original Message-----
> > > From: [EMAIL PROTECTED]
> > >[mailto:[EMAIL PROTECTED]]On Behalf Of Paul W. J.
> > >Stanley
> > > Sent: Saturday, 28 April 2001 11:50
> > > To: OZDAT Mailing list
> > > Subject: The "Datsun Miss"
> > >
> > >
> > > The Datsun Miss is still haunting me. Now I have an L20B in the 200B
> > >with
> > >the standard downdraft carby, and I assumed the mmiss was from the
points
> > >that looked as though they had done 100,000km so I had the pleasure of
> > >vulturing my friend's L20B since he has fitted a fancy CA18DET. Anyway
I
> > >fitted the electronic dizzy and after figuring out that my cylinder 1
was
> > >at
> > >the back (firewall) of the engine, and the back driver's corner of the
> > >dizzy
> > >(is this normal?) only to discover the miss was still there.
> > > Now I'm suspecting either a combination of LRP and dirty carby
(doubt
> it
> > >though...it's not a flat spot...just a regular single miss)
> > > Or it could be the old conections and wires powering the coil...need
> to
> > >replace the 70s ones with new millenium ones maybe. I've tried numerous
> > >leads and spark plugs, checked all the gaps etc
>
>
>
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