mr-wiggly

New Member

• Mar 20, 2011

• #1

I'm still having problems with my p-reg 3.9 manual disco,its revs are still going up and down all the time,when started it goes up to 2000rpm then drops to 1200rpm guess this is automatic choke,then when driven short or long distances and you have to stop at some lights, it can rev at 1500rpm or sometimes 900rpm etc.. basically it does what it wants .

I've changed the idle control stepper motor on the back of the top plenum,checked for air leaks when cold and put the standard air box and filter back on, cleaned the throttle positioning sensor on the front of the engine and also checked the throttle cable isn't fowling,

anymore help would greatly appreciated as its starting to get on my tits now

 

nathan5346

Well-Known Member

• Mar 20, 2011

• #2

On petrol and lpg?

 

discool

Well-Known Member

• Mar 20, 2011

• #3

First Check/Reset your base idle and clean the crankcase breather and pipe. Check plugs/leads & coil connections are all ok.

Fuel injection engines don't have a choke, instead they inject extra petrol to giving a richer mixture when starting from cold, you should start with around 1500rpm but within 10-15seconds drop down to 1000 and then to normal idle revs, mine are around 650.

 

mr-wiggly

New Member

• Mar 20, 2011

• #4

Its running petrol as the lpg hasnt worked for ages as the vapourisor is knackerd as pervious ower broke the bottom pipe off,
where abouts is the base idle control located?
Some one said the idle maf might be knackerd, its a nightmare really as lost my job last week so struggling with spare cash to keep throwing at it.

 

discool

Well-Known Member

• Mar 20, 2011

• #5

It's not a control but a procedure and it's shown in the workshop manual along with more info on Efi engine running problems. http://www.landy.pl/LandRoverDiscoveryWorkshop1995-1996.pdf

 

mr-wiggly

New Member

• Mar 20, 2011

• #6

What would the symtoms be if the maf was fooked?disco has new plugs,leads,dizzy and coil.

 

Tervueren

New Member

• Mar 20, 2011

• #7

Plenum Butterfly sticking ?

 

mr-wiggly

New Member

• Mar 20, 2011

• #8

Its been cleaned and seems free enough, earlier car was hunting like mad? Wtf