1975 2.0 Engine trying to stall out when hot... and a couple missing parts Options

[engine247]

Howdy,

I have a 1975 2.0 that I recently acquired. It did the 3 hour drive home; no problem. I’ve put probably 100+ miles on it since with no problems other than a high idle. (~1800 rpm which I know is high but it still ran smoothly)

Issue #1
Until I took it out the other morning. I parked it and went to the spring game during which time the temperature climbed to 90+ degrees. On the way home after about 5 blocks while sitting at a light; the rpms suddenly just dropped. I kept it going but it would just bog down and attempt to stall. Then it would surge back to normal and go half a block and then just drop out again; no power and trying to stall. So I parked it and grabbed a ride home. Since the only thing out of the norm was that this was the first 90+ day I’ve had it. I decided to go back and give it a try at dusk once the temperature had dropped. Sure enough it fired right up and I drove it home with no issues.

Issue #2
After some researching, I figured between Issue 1 and the high idle I would poke around looking for vacuum leaks, checking for a stuck open AAR, etc. I popped the air filter housing off to get a better view and was surprised when I could find the AAR. Turns out there is no AAR or Decel valve. The CSV is unplugged as well. Obviously, it has run without them but I’m not sure that is the best long-term option. I also don’t know if this would contribute to/exacerbate Issue #1.
(side note: not sure about the how the hoses are run. For example the hose running from the throttle body (retard?) to the oil filler and not the distributor? And is that a 1.8L oil filler?)

I haven’t experienced Issue #1 again but it also hasn’t been hot out if that had anything to do with it.

Last observation: I put the air filter housing back on; tightened it up on the throttle body then put the hoses back on. Idle at start-up dropped to ~900. After warming up for 5-10 minutes it climbs up to ~1200 and settles. So maybe there was a bit of vacuum leak in one of those connections and still a bit more elsewhere that I can look for. However, it run worse than before. Any time rpms are below 3000 it runs very choppy, especially when accelerating.

So any ideas on my best move forward? Are they separate issues or maybe intertwined? Address one before the other independently? Which one first?