Annoying rough running problem - UPDATE

G

Guest

Guest
Hi y'all!
The saga continues.
This morning I had to drive to see a client - about 20 miles so I stuck
the LC on petrol mode fired her up and of I went. No trouble at all,
drove like a dream! Switched back to LPG, had the usual slight power
drop (normal with LPG vs petrol and it drove fine. Back onto petrol,
100% AOK. Whatever I did I could not recreate the problem.
Got to client, did job, stated to drive back. Again 100% AOK untill I
got stuck in standing traffic when it started running rough again. Not
as bad but similar, again fine on LPG. Got home and parked up, left
engine running on petrol and checked under the bonnet. It's idling
OK'ish - a little rough but nowhere near as bad as it has been. No sign
of the plunger thingy rising and falling - it's stationary.
I've also found out a little more about this plunger thing. The
'adjuster screw' that it abuts is an adjuster screw but the metal
bracket that said screw sits in is actually a throttle lever. I never
thought to se if it moved last night but it does; if you rotate the
lever away from the plunger it opens the throttle on the same cam as the
hand throttle inside the cab uses. So, it seems that said plunger thing
is supposed to open the throttle when it moves upwards but it never gets
far enough to do that. Still don't know what makes the plunger move though.
All the vac hoses seem OK although I haven't had a chance to properly
test them all yet.
Anyway, to summarise:
It was fine this morning and for a 20 mile drive plus 3/4 of the return
journey.
It then ran rough again but not as bad as before
The plunger is no longer cycling in / out and niether is the engine
roughness cycling.
So, Brendan Lalleys earlier post about the intermittent nature of this
problem was prophetic in a way!!
I'll keep you informed but any further hints, especially about the
nature of the plunger thing I'd appreciate it.
Pete
 
G

Guest

Guest
Hi Peter,
I have looked at the photos that you sent, but unfortunately they
aren't that clear (if you want to send higher res ones, no problem).
On the diagram the plunger DP thing actually looks like it is
controlling the throttle butterfly valve or something similar, but it
isn't that clear.
I guess one thing to do is to trace the pipework/wires from the unit
(assuming there are some) to see if they lead to anything obvious.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
G

Guest

Guest
Hi Peter,
I have looked at the photos that you sent, but unfortunately they
aren't that clear (if you want to send higher res ones, no problem).
On the diagram the plunger DP thing actually looks like it is
controlling the throttle butterfly valve or something similar, but it
isn't that clear.
I guess one thing to do is to trace the pipework/wires from the unit
(assuming there are some) to see if they lead to anything obvious.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
G

Guest

Guest
The plunger is certainly bearing on the throttle butterfly but even at
full extension it does not move the buttlerfly arm.
Can't see any pipework emanating from it, it seems to be embedded in the
manifold.
The diagram BTW is for a 62 series( whatever that is), not an 80 but
it's the only remotely similar diagram in the whole of haynes, none of
the 80 series diagrams have anything remotely like it.
Enhanced pictures attached.
Julian Voelcker wrote:
>Hi Peter,
>
>I have looked at the photos that you sent, but unfortunately they
>aren't that clear (if you want to send higher res ones, no problem).
>
>On the diagram the plunger DP thing actually looks like it is
>controlling the throttle butterfly valve or something similar, but it
>isn't that clear.
>
>I guess one thing to do is to trace the pipework/wires from the unit
>(assuming there are some) to see if they lead to anything obvious.
>--
>Regards,
>
>Julian Voelcker
>Mobile: 07971 540362
>Cirencester, United Kingdom
>1994 HDJ80, 2.5" OME Lift
>
>
>--
>European Land Cruiser Owners Mailing List
>Further Info: http://www.landcruisers.info/lists/
>
>
>
>
>
 
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G

Guest

Guest
Oops, sorry.
Last message was HTML and with a read receipt request.
Pete
Julian Voelcker wrote:
 
G

Guest

Guest
Hello again!
Checked the fault codes this morning and the ECU reported that it was
extremely happy with life and had no issues; at least none that it's
psychoanalist couldn't sort out! :)
Stripped out the middle seats and removed the fuel pump assembly by way
of the inspection plate. The mesh filter on the pump had a small amount
of 'fluffy' dirt on it, not enough to cause any problem i would have
thought but I cleaned it anyway.
Put it back together and fired her up.... it ran perfectly OK!
Now I'm not jumping up and down cheering just yet because this problem
has already shown itself to be intermittent and I don't really believe
that I've done anything significant but the engine does now seem to run
a lot smoother.
We'll see how it goes next week.
Pete
 
G

Guest

Guest
Peter,
What kind of LPG system do u have (vaporiser, emulator etc.)
Do does it connect from the vaporiser into the 'engine'?
the IAC (Idle Control) or TPS (Trottle Position Sensor) - both of these are
on the front and top of the engine. Can u modify the photos and out on a big
arrow?
When mine was giving issue it rarely give any ECU codes.
Also wen u indicate the butterfly and movement is that 'seen' by u when
looking at the engine (while its turned on and u're tweaking
trottle/acclerator) or only when u do some disassemble (to see into the
'units'?)
Also there was a 'feature' (on the LPG ECU emulator) where if u connected
one of the wires it would wipe out any stored ECU codes once it switched
back to petrol. This was a known 'issue' in that some O2/engine ECU's were
sensitive to the 'emulation' going on and would often report a code and trip
the MIL (check engine light). As such it was a pain to go check it every
time to find out P401 (I think) or nothing. So the wire 'feature' got rid of
that.
I use that on mine now as I never found a code "worthwhile" and everything
ran fine. Once on petrol, and staying on it for quite awhile including
several restarts etc., it never complained and hence my belief it was a
false reading.
I can give u the number of my LPG man in Scotland who is very helpful and
maybe worth a chat. He has done a LOT of LPG conversions and at least 4+
80s.
Lal
[Email address removed]
-----Original Message-----
From: [Email address removed]
[mailto:[Email address removed]]On Behalf Of Peter Browning
Sent: Friday, September 16, 2005 9:06 AM
To: [Email address removed]
Subject: Re: [ELCO] Annoying rough running problem - UPDATE
The plunger is certainly bearing on the throttle butterfly but even at
full extension it does not move the buttlerfly arm.
Can't see any pipework emanating from it, it seems to be embedded in the
manifold.
The diagram BTW is for a 62 series( whatever that is), not an 80 but
it's the only remotely similar diagram in the whole of haynes, none of
the 80 series diagrams have anything remotely like it.
Enhanced pictures attached.
Julian Voelcker wrote:
 
G

Guest

Guest
Hi Brendan
It's a vapouriser system injecting into the inlet manifold where the air
inlet rubber hose connects to the manifold. The whole caboodle is
controlled by a 'Leonardo' ECU emulator.
The plunger affair I was pointing out is just below the TPS and it looks
as though it is designed to act by opening the butterfly. Interestingly
if the throttle is 'blipped' hard the plunger extends markedly so it
looks to be activated by an increase in vacuum. When the revs were
dropping and the engine was about to stall the plunger extended in a
linear relationship to the revs dropping but it never extended enough to
actually move the butterfly actuator.
All this is seen just by looking at the exterior of the engine, no
dismantling involved.
I have never had any issues with false (or any) check engine codes being
generated in the past and I don't think there was any 'wipe out' feature
connected from the emulator.
Anyway, as I said earlier, cleaning the fuel pump filter mesh 'seems' to
have had a positive effect; I'll know more once I've taken it for a
decent drive.
Pete
Brendan Lally wrote:
 
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