I am suffering from a very erratic idle on a 2.5ltr sve lpg converted car,
currently 58,000 miles. The car is an automatic, and seems to function fine
in all other manners, but, when put into neutral the revs jump up and down
from 1500 to 2200rpm making the kind of noise you would get from
deliberately revving the engine. The car functions in all other ways ok,
when in drive, with the brake on, there is no rev problem, but then the
engine is engaged... There is a consequence of this, at speeds of low revs,
the car gets a slight jerk forward as it pushes up from the 1500 to 2200.

This happens whether or not the car is running on lpg or petrol, but doesnt
happen when the car is first started up, ie it runs for a short while before
the problem happens.

A general mechanic who has done work for me in the past, said his fault
finding equipment couldnt pick anything up and suggests i go to dealer and
see if their system can locate the fault.

I dont know much when it comes to cars, but have read about lpg messing up
some valves, and i do know that it has some 'valve saver' fluid bottle
fitted.

Any help would be greatful.

Smurf wrote:
I am suffering from a very erratic idle on a 2.5ltr sve lpg converted
car, currently 58,000 miles. The car is an automatic, and seems to
function fine in all other manners, but, when put into neutral the
revs jump up and down from 1500 to 2200rpm making the kind of noise
you would get from deliberately revving the engine. The car functions
in all other ways ok, when in drive, with the brake on, there is no
rev problem, but then the engine is engaged... There is a consequence
of this, at speeds of low revs, the car gets a slight jerk forward as
it pushes up from the 1500 to 2200.
This happens whether or not the car is running on lpg or petrol, but
doesnt happen when the car is first started up, ie it runs for a
short while before the problem happens.

A general mechanic who has done work for me in the past, said his
fault finding equipment couldnt pick anything up and suggests i go to
dealer and see if their system can locate the fault.

I dont know much when it comes to cars, but have read about lpg
messing up some valves, and i do know that it has some 'valve saver'
fluid bottle fitted.

Any help would be greatful.

sorry, model nissan x-trail 05 petrol

can you get the motoring section of the Sunday Times ?
V similar issue yesterday asked
"Smurf" wrote in message
...
Smurf wrote:
I am suffering from a very erratic idle on a 2.5ltr sve lpg converted
car, currently 58,000 miles. The car is an automatic, and seems to
function fine in all other manners, but, when put into neutral the
revs jump up and down from 1500 to 2200rpm making the kind of noise
you would get from deliberately revving the engine. The car functions
in all other ways ok, when in drive, with the brake on, there is no
rev problem, but then the engine is engaged... There is a consequence
of this, at speeds of low revs, the car gets a slight jerk forward as
it pushes up from the 1500 to 2200.
This happens whether or not the car is running on lpg or petrol, but
doesnt happen when the car is first started up, ie it runs for a
short while before the problem happens.

A general mechanic who has done work for me in the past, said his
fault finding equipment couldnt pick anything up and suggests i go to
dealer and see if their system can locate the fault.

I dont know much when it comes to cars, but have read about lpg
messing up some valves, and i do know that it has some 'valve saver'
fluid bottle fitted.

Any help would be greatful.

sorry, model nissan x-trail 05 petrol

"Smurf" wrote in message
...
I am suffering from a very erratic idle on a 2.5ltr sve lpg converted car,
currently 58,000 miles. The car is an automatic, and seems to function fine
in all other manners, but, when put into neutral the revs jump up and down
from 1500 to 2200rpm making the kind of noise you would get from
deliberately revving the engine. The car functions in all other ways ok,
when in drive, with the brake on, there is no rev problem, but then the
engine is engaged... There is a consequence of this, at speeds of low revs,
the car gets a slight jerk forward as it pushes up from the 1500 to 2200.

This happens whether or not the car is running on lpg or petrol, but
doesnt happen when the car is first started up, ie it runs for a short
while before the problem happens.

A general mechanic who has done work for me in the past, said his fault
finding equipment couldnt pick anything up and suggests i go to dealer and
see if their system can locate the fault.

I dont know much when it comes to cars, but have read about lpg messing up
some valves, and i do know that it has some 'valve saver' fluid bottle
fitted.

Any help would be greatful.

Two things spring to mind on the xtrail 2.5 - throttle body fault, idle
adaption needs to be re-learnt (google for this), or you have a split hose
in the PCV system.

Check those in reverse order (£ to ££££)

Tim.

Smurf wrote:
Smurf wrote:
I am suffering from a very erratic idle on a 2.5ltr sve lpg converted
car, currently 58,000 miles. The car is an automatic, and seems to
function fine in all other manners, but, when put into neutral the
revs jump up and down from 1500 to 2200rpm making the kind of noise
you would get from deliberately revving the engine. The car functions
in all other ways ok, when in drive, with the brake on, there is no
rev problem, but then the engine is engaged... There is a consequence
of this, at speeds of low revs, the car gets a slight jerk forward as
it pushes up from the 1500 to 2200.
This happens whether or not the car is running on lpg or petrol, but
doesnt happen when the car is first started up, ie it runs for a
short while before the problem happens.

A general mechanic who has done work for me in the past, said his
fault finding equipment couldnt pick anything up and suggests i go to
dealer and see if their system can locate the fault.

I dont know much when it comes to cars, but have read about lpg
messing up some valves, and i do know that it has some 'valve saver'
fluid bottle fitted.

Any help would be greatful.

sorry, model nissan x-trail 05 petrol

Maybe worth registering and asking the question at
http://www.lpgforum.co.uk/

I am suffering from a very erratic idle on a 2.5ltr sve lpg converted
car, currently 58,000 miles. The car is an automatic, and seems to
function fine in all other manners, but, when put into neutral the
revs jump up and down from 1500 to 2200rpm making the kind of noise
you would get from deliberately revving the engine. The car functions
in all other ways ok, when in drive, with the brake on, there is no
rev problem, but then the engine is engaged... There is a consequence
of this, at speeds of low revs, the car gets a slight jerk forward as
it pushes up from the 1500 to 2200.
This happens whether or not the car is running on lpg or petrol, but
doesnt happen when the car is first started up, ie it runs for a
short while before the problem happens.

A general mechanic who has done work for me in the past, said his
fault finding equipment couldnt pick anything up and suggests i go to
dealer and see if their system can locate the fault.

I dont know much when it comes to cars, but have read about lpg
messing up some valves, and i do know that it has some 'valve saver'
fluid bottle fitted.

I run an LPG van, and the general rule of thumb is if it does it in petrol
mode it is unlikely to be LPG related.

Bit of an unlikely one but a problem i had recently the floor mats are not
interfeering with the throttle pedal are they?

Kipling wrote:
I am suffering from a very erratic idle on a 2.5ltr sve lpg
converted car, currently 58,000 miles. The car is an automatic,
and seems to function fine in all other manners, but, when put
into neutral the revs jump up and down from 1500 to 2200rpm making
the kind of noise you would get from deliberately revving the
engine. The car functions in all other ways ok, when in drive,
with the brake on, there is no rev problem, but then the engine is
engaged... There is a consequence of this, at speeds of low revs,
the car gets a slight jerk forward as it pushes up from the 1500
to 2200. This happens whether or not the car is running on lpg or
petrol,
but doesnt happen when the car is first started up, ie it runs for
a short while before the problem happens.

A general mechanic who has done work for me in the past, said his
fault finding equipment couldnt pick anything up and suggests i go
to dealer and see if their system can locate the fault.

I dont know much when it comes to cars, but have read about lpg
messing up some valves, and i do know that it has some 'valve
saver' fluid bottle fitted.

I run an LPG van, and the general rule of thumb is if it does it in
petrol mode it is unlikely to be LPG related.

Bit of an unlikely one but a problem i had recently the floor mats
are not interfeering with the throttle pedal are they?

nah, thanks for the suggestion though.. i have it booked with the dealer in
the morn

Smurf wrote:
I am suffering from a very erratic idle on a 2.5ltr sve lpg converted
car, currently 58,000 miles. The car is an automatic, and seems to
function fine in all other manners, but, when put into neutral the
revs jump up and down from 1500 to 2200rpm making the kind of noise
you would get from deliberately revving the engine. The car functions
in all other ways ok, when in drive, with the brake on, there is no
rev problem, but then the engine is engaged... There is a consequence
of this, at speeds of low revs, the car gets a slight jerk forward as
it pushes up from the 1500 to 2200.
This happens whether or not the car is running on lpg or petrol, but
doesnt happen when the car is first started up, ie it runs for a
short while before the problem happens.

A general mechanic who has done work for me in the past, said his
fault finding equipment couldnt pick anything up and suggests i go to
dealer and see if their system can locate the fault.

I dont know much when it comes to cars, but have read about lpg
messing up some valves, and i do know that it has some 'valve saver'
fluid bottle fitted.

Any help would be greatful.

thanks for those that responded, nissan looked at it today:
"sticking throttle flap, stripped and cleaned, fault fixed"
"throttle body/butterfly sticking-high idle"

all fine now