So I went to a shop and had my adaptive values reset trying to chase this idle problem. He found a vacuum leak that I overlooked so we're pretty sure the idle issue is because of the leak.

I'm going to pull it apart and replace the valley pan gasket and end seals as we'll as the injector seals.

Anyway I'm putting on a new upper plenum with the other stuff because mine has been tampered with and I don't trust it. I can't seem to find the upper gasket listed anywhere though for a disco 1, only for the disco 2. Is it reusable or am I missing something?

Also are there any quirks to be aware of when pulling the intake manifold off? Thanks again!

 

There is no upper gasket , uses an anaerobic sealant, machined mating surface

I use something like ultra black rtV smeared thin though I am sure parts store has correct stuff

 

Well that makes sense (Palm to forehead) hopefully I get this thing sorted out over the next few days. Thanks Tom

 

not sure it matters what sealant you use, i have seen orange, grey, blue in that spot but the ultra grey, ultra black, or right stuff work best for me use sparingly since you do torque that together and be sure all is clean and degreased, with rtv allow 24 hrs before starting engine, you will also need it for the valley gasket ends

like i said there is a correct type though, d2 has a gasket

additional thought, my valley was leaking oil did it then ended up doing head gaskets later so in the end was a waste, my valley was bulged and leaking though from clogged pcv and bad pcv hoses everything was crudded up in the throttle body too all from po not changing oil and poor maintenence