Thread: Idle prob, disco 94 3.9v8

for the idle pull the stepper motor off from back left of plenum and clean with carbie cleaner remember to clean in the hole aswell. Also check for vacum leaks by getting a piece of hose and putting it to your ear while moving other end around the engine, You should hear any vac leaks.

Thanks Mate, im not sure what a stepper motor and plenum are but i gotta try to find it. Its def not any vac hose because the mechanic tried them all.
Cheers

????

Originally Posted by march

Thanks Mate, im not sure what a stepper motor and plenum are but i gotta try to find it. Its def not any vac hose because the mechanic tried them all.
Cheers

Photos of the plentium & stepper unit

Originally Posted by mike 90 RR

THIS PHOTO SHOWS THE PLENTIUM (In top RHS of photo) ... from the drivers side ... it shows the stepper unit at the back of it ... has black insulation over the wire going to it ... connection is a square 4 pin plug with a green internal seal

Stepper unit also has
..... a 16mm (approx) vacuum hose going back to the throttle body
..... a 6mm (approx) vacuum hose going to a round can on the fuel rail ... this the fuel pressure regulator




THIS PHOTO SHOWS THE PLENTIUM ... from the passenger side ... it has the 3.9 embossed in it (big aluminium box? in center of motor) ..... At the back of the plentium you can actually see the 16mm & 6mm black vacuum hoses

If you have a girlfriend ... go nick her make up mirror and a torch .... Put the mirror behind the plentium and shine the torch into the mirror .... Move the mirror around to see the stepper unit

Mike

[QUOTE= If you have a girlfriend ... go nick her make up mirror and a torch .... Put the mirror behind the plentium and shine the torch into the mirror .... Move the mirror around to see the stepper unit

Mike[/QUOTE]

What will you find by doing this a vacum leak

Originally Posted by jezz

What will you find by doing this a vacum leak

If I read the quote right ...

It will give you the ability to see .... what the whole stepper unit looks like .... without having to remove it


The vacuum part will appear if the girlfriend finds out you are using the mirror


Mike

mate what you have described it could be (in my limited experience and only from experience) a sign that your rotor shaft cir clip could be broken inside of the dizzy ...mine was doing what your describing a long while and after some painstaking searching we found that was the problem ...but be careful as when the clip get old it will disintegrate if pushed around to much ...(as mine did )..after some searching i found a dizzy service pack @ $100.00 from rover craft in wa...(this is the only way you can get the little nylon circlip...but i decided to go for a new dizzy instead


cheers

I solved this one on my '95 3.9 about two weeks ago. Tried everything, and from what I've read around the place, cleaning the stepper is a good first step.
Mine turned out to be the temp sensor for the computer.
$22 plus postage frpm Land Vehicle Spares in NSW.



Now, see just above the oil filler, the shiny black plastic looking thing with the wire attached? that or very close to that is the temp sensor. Order one, look at it, replace the thing that looks the same in the region that I've indicated. Problem solved hopefully for minimum dollars.