wierd idle problem

[pete2528ca]

Hey gang...

Over the last couple of days, I've noticed this problem. The truck runs great, then maybe after three or four times its been turned off and on, it idles really bad, like under 200 rpm, engine stalls, so I have to turn it on, and give it some gas, and then once its moving its fine. then starts up no problem. Occasionally it will have a rough idle but nothing serious. It is a 97 disco with new bosch platinum plus fours, new o2 sensors and new 8mm magnacor wires.

Help

Pietro

 

[LRWheelman]

Fuel Filter? Fuel Pump maybe . . . . Did it run Ok after the "tune up" ?? Good Luck, LRW

 

[joey]

Stepper motor needs cleaned, or you need to run some cleaner throught the system (seafoam or similar)

 

[pete2528ca]

i've run two bottles of the land rover fuel system conditoner. where is the stepper motor located.

Pietro

 

[Moose]

Do a search for stepper motor or IAC. It's mounted on the front side of the intake plenum, right by the breather hose that runs approx 3" between valve covers and intake. It's got a muti-plug in it, and two 5.5mm screws. Remove, soak/rub with carb cleaner, replace.

 

[capthook]

The stepper motor (or Bosch constant idle speed valve) is located (normally) near the top of the motor + looks like a round body with two hoses comming out of either end @ the top of the unit. Simply unscrew the unit + detach the harness from the end. Now take some cheap Carb-Cleaner (this cuts better IMO than a seafoam treatment, and you have the valve off anyway) and hold your finger over both ends and shake it w/ the carb cleaner inside the unit. All the carbon build up will come out of the unit, keep doing this until it looks pretty clear & now you have a clean valve.

Another note, let the unit dry out for an hour or so before you attach it to your truck again or it will run poor.

http://www.autobytel.com/images/car...RoverDiscovery/2003_discovery_engine_700w.JPG

Note 4.0 v8 Idle Valve (stepper motor) location near the back right (see the two hoses connecting into the unit? mine has green label)

 

[vandermeulen]

On my 96' 4.0L V8 Gems motor, my IAC (Stepper Motor) is on the front side of the plenum.
I have almost the same problem. Mine is at a constant lower idle (just under the 700 mark) all the time. When I've driven the truck for awhile the idle will fluctuate and if I try to start it when hot recently the idle will go down real low (200 rpm) then start to clime gradually as I drive it.
This past weekend I cleaned the Stepper Motor and throttle body but it didn't help.
Is there any other items I can check?

(Truck has no mods....about 80,000 miles.....same O2's as far as I know)

 

[capthook]

Wow, that sounds like something else if (when you start it hot) the truck idles at like 200 rpm's. I'd have my codes scanned, see if that Air flow meter (BOSCH Air Mass Meter) is giving a proper reading. It's internals have alot to do w/ temps + air flow but most of the time when they go the engine runs really rough and / or not @ all. By the way, I don't know who still scans your codes for free so anyone who knows? I know Pep Boyz charges u $20 now I think..

Capt

 

[pete2528ca]

thank you everyone for the input.

Ill try the stepper motor.

pietro

 

[vandermeulen]

Good luck with the stepper motor. Seems a lot of people have good luck with cleaning it.
I have a code reader, but beleive it or not I'm not getting any codes at all.
Not sure exactly what might be the problem, but I'll keep checking around.

I also have the Disco shakes at high speeds and numerous other little items to be fixed.

I love my Rover but it's probably the worst vehicle I've ever owned (and I even had a 95' Plymouth Voyager before this).....yet for some reason I can't quite understand I keep wanting to try cus I like it so much.