I've seen this type of issue once before on another forum where codes where many and high idle. Ended up being the ecm and it was due to board trace corrosion. Your codes are not the usual plain vanilla types which makes me think something is really amiss with the ecm. Did you do anything with the molex connector to the ecm?

 

ihscouts is correct, and I have lived thru the 2000 rpm idle with a couple of IACVs. I finally pulled a used IACV and matching ECU and it ran smooth and correct rpm since then. About $40. Would adaptive value reset have done it? Maybe, but higher cost for me.

 

by molex connector do you mean the harness plug for ecm? if so I dielectric greased it when computer was out

if I can get an ecm used do I need the alarm ecu also ? does it have to be from a 1998 disco?

if I remember trace means the board has gone bad not the components on the beard and is non fixable correct?

when I left the dealer idle was 1300 then drove 40 minutes to dads shut off, at resart( still warm) 900 then slowly climbed back to 13/1400

 

Yeah, I thought you mentioned dielectric in a previous post.

It's not a bad idea to grab the alarm just in case. Some have had no issue with their alarm working (Higgs Boson and Savannah) with a new ecm. I grabbed mine from Paul Grant who only sells them paired.

Since you have AEL you'll need 97 1/2 - 99 1/2. I would grab the latest possible since it will have newer firmware which can make a difference in engine tune. LR modified the code as the line matured.

Traces are fixable with the pro equipment and the patience of a saint. I'd go the newest ecm route if I was you.

 

does it have to be a a disco or will range rover also work? and where is the alarm mounted?

gonna try to hit upull sunday when I get off duty

I was just trying to figure if it would be worth sending the ecm to a rebuilder

 

Haven't heard of a RR GEMS swap and I doubt they would cross over simply because of the body control unit. Alarm is a plastic green box near the ABS ecu which is silver, passenger side under glovebox nearer to kick panel. Can't miss it.

Not worth sending out, keep it cheap. See if you can nab a couple of units.

 

OK finally home ran the engine and now the idle wanders and so does the tps reading tps is wander in at idle from 5.24 to 12.2, ideas?

 

No TPS% should be stable. TPS sensors are "volume controls" (potentiometer) and if "noisy", they will make ECU think you are patting your foot on the throttle. Don't know if they are sealed up well enough that electronic cleaner can't get in there.

 

OK I will try that,is there a cross over p/n if I need a new one? $ 100+ seems high

 

pre-owned?