Started my Disco this morning, and outa nowhere idles at like 1500rpm. Been running/idleing fine before this.

So no big deal I think, I'll pull the stepper motor and clean everything out. Just cleaned the t-body bout 3 months ago, and gave it a one over for vacuum leaks as i removed and cleaned it.

Put it back together, started her up and ran it a bit, and idled at like 400-500rpm.

Pulled it again, douched it out again with carb cleaner. Back together. Idle's about 900rpm.

Sound like I might want to replace it? The plunger cone end was pretty gouged up when I cleaned all the crud off.

And it threw no CEL codes.

 

If the plunger is all gouged and cant make a good seal it might be time for a new one.

If you need to you can take pipe cleaner and using carb cleaner you can clean the hole that the plunger seats in making sure that all the ports that you can see/reach and not plugged.

 

I used q-tips to get in there, making sure I didn't leave any cotton behind.

I'm just afraid with a new one, my ecu might not run it right- think thats what I found in a few threads when I searched

 

Yeah it is a crap shoot whether or not the truck will like the new one or not.
It is also a crap shoot whether or not a non Rover one will work.
One from a Jeep 4.0 ($50) is a direct replacement but 50/50 if it will work or not.

 

Hmmm, I'm not a gambler but dont like 50/50 odds

 

I've got one i can sell you that i pulled from my 99 d1. thought my problem was the iac, so i bought a new one and installed it. it wasn't. so i've just got one hanging around. new, they are around $180. i'll sell mine for $50. let me know.

 

What did you're problem end up being? And yes, I would be interested in buying it, I'll pm you in a day or two, I wanna make sure thats whats wrong

 

throttle plate wasn't resting flush. making it run lean. with high idle. it was actually bent. no clue how.

 

OK. I "borrowed" my buddies stepper motor, and still idles high,2k cold, 1.2k warm.

Would a good test be to start the car without the stepper in there, and plug the ports with my finger? See if it idles down?

If it aint the stepper motor, TPS?

I once over'd for vacum leaks again, inspected the throttle plate, all good.

Ideas?? Still no codes

 

Yup probably the TPS. I drove myself nuts with the same thing swapping out steppers and hunting down vac leaks. I suggest that as you got it to idle at 400rpm would indicate no vac leaks...

IMHO I think the reason the non rover (Airtex etc) steppers seem to be 50/50 maybe the TPS instead. I have used 2 Airtex steppers and they were fine once the TPS was replaced.

Alan
98 D1