I've been reading up on high idle issues and trying different things. But haven't found the problem yet. Here is what I know.

- 96 Discovery.

- Seems to run around 1200 rpm when cold. Then after engine warns up and I'm driving it will run idle up to 1800(ish) when pull up to a intersection and push the clutch in. Then after about 4 seconds it goes does to 1200. then after about 2 seconds it goes down to 1000 rpm.

- I removed and cleaned IACV. Yes it was dirty. (pic attached below). Replaced it and still having issues. Also noticed it didn't have a gasket or o-ring on it. Seems like it should? I found a $10 IACV on ebay new that includes a o-ring so I might try that.

- ODB2 port says my TPS is at 12% which is correct according to some other posts I read.

- Water temp sensor is working. (I'm guessing) Cause I can read it on the ODB2 port. at running temp its around 180-190F

- I have not tried to disconnect the TPS or IACV as I have read that might not be a good idea?

- I have read that a ECM re-program by a landcover specialist also may fix this issue but thought I would try these quick fixes first. I also have a SRS light on and maybe the ECM reset would fix that issue too so might not be a bad idea?

Looking for suggestions on what I should do next. Thanks!

 

Where did my post go?

 

Well thats annoying. Not sure where my original post went. I guess I'll try to explain again.

It's running around 1000rpm cold, then once it warms up and after I push the clutch in the engine goes up to around 1800rpm for about 5 seconds then goes to 1200rpm for about 2 seconds then down to 1000. (never goes below a 1000)

I've read several posts on this issue. And I have already cleaned the Idle Air Control Valve (IACV) . Picture of dirty IACV attached. But noticed I don't have a o-ring on mine. Maybe there is a vacuum leak? (I'll work on checking that out)

The TPS is show steady at 12% on my ODB2 reader. So looks like my TPS is working good?

The water temp is showing above 180F on my ODB2 so I don't think it's that issue.

Other ideas? Is there a way to test the IACV?

 

Hmm I am a bit curious as to this as well. As mine does about the same, well cept it normal idles round 800rpm, and jumps up to round 1600-1800rpm depending on the time lol. Have tried to clean the iacv and the tps. Right now am waiting on a new throttle cable.

 

Just found this (link below) to a issue that seemed the same, will have to check mine later but hopefully this will help ya out

https://landroverforums.com/forum/di...gh-idle-32201/

 

You have to clean the bore seat the pintle sits on too. Once you've done that then the IACV is clean. Report back once you've done this, there's a trick to reset it that sometimes works.

 

Ok. I re-cleaned the seat and all the little ports down in there. The high throttle seems to be acting a little different but is still having a high throttle issue. And it still seems to be working better when the vehicle is cold. Once it has warmed up the high throttle kicks in.

I'm interested in hearing about this reset option.

Is there a way to test if the IACV is moving in and out correctly?

 

Unplug the IACV, turn ignition to position III, count to 10, turn ignition off, plug IACV in, turn ignition to position III, count to 10, turn ignition off. Do not attempt to start motor. Do this three times and hopefully the ECM relearns the pintle position for the IACV. The other method is just to put some miles on it and maybe it will settle. If these fail you'll need to find a garage that can reset it. Independent garages are cheapest.

The IACV is a four wire solenoid, position in and out. All you can do is check it for frame ground for a broken connection and continuity between wire pairs. When it's working you should hear a one second buzzing noise coming from it when ignition is first turned off. It's resetting position for next cycle.

 

Your location will help find a Indy shop to reset it, IACV should have a gasket if same as my 98

 

Thanks for all this help. After doing what you said it didn't make a difference with the idle. So I have another question. If I were to disconnect the IACV after I start the engine (and the rpms are low) then rev the RPM up and it should go back down to a low rpm right? It seems like this would at least indicate that the IACV is moving or not because it should act different.