Well, I'm getting ready to tackle my vacuum system under the hood. I am certain that some of the vacuum lines are suspect, due to age. What are the common OD/ID of these lines, and what type of replacement hose is recommended? This is a broad question, I realize. I am trying to avoid running to the store more than once.

This is on a 1980 245 DL Manual w/OD B21F engine. The car runs, idles rough when cold (temp sensor mounted in block suspect, bad connector, mounted towards back of block, driver's side, underneath intake manifold), has a stumble/cough sometimes around 2500 RPM while accellerating, especially in 2nd.

I intend to check the vacuum lines by spraying them with carb cleaner while the engine idles. After I do this, I will set the base idle with a DVM for 50% duty cycle (maybe a little richer). I'll link some pictures and post my progress - this could take several tries, but I intend to get the engine running right, even if it means a new wiring harness.

I have already cleaned the throttle body, intake manifold, air box, cold air idle valve (not sure how to test its functionality), injectors, cold start injector, etc.

Any other suggestions?
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Ten Sleep 1980 245DL 1995 850 Turbo