Here's the situation. 1984 Subaru DL 2wd 5spd 2door. Had EA71, swapped in an EA81 and de-smogged the feedback carb. Ran like it had a vacuum leak from day one so I stopped driving it. Fastforward to today. I've dropped a rebuilt Weber in there and replaced the crappy cardboard intake gaskets with legit Subaru intake gaskets. With the intake sitting on the heads there was no rock to the intake, so I know the surfaces are pretty well planed. I clean up the engine bay a bit and get the Weber adjusted according to what the Weber site says it should be to start off before final tune. Well, it's doing the exact same thing as before. Stumbling, high idle, seems to be running lean and while messing with the idle mixture it kept falling on its face. Was kinda hard to keep it running and play with mixture.
Something else I have not done however is properly set the timing, used an EA82 flywheel. I'm wanting to say it's close BUT I could not say for sure because I can't get it running well enough to tune it by ear.
So, I'm at a loss here. I know I should get a vacuum tester but I'm certain it's low on vacuum because the brakes barely want to work. But for the life of me, I CANNOT find ANY air leaks WHATSOEVER ANYWHERE on the carb or intake. I went through 2 cans of brake cleaner today trying to find a leak but NOTHING. What do I need to do, step by step, to figure out what is going on here? Could this be a sticking valve? Could the timing being off cause this? Exhaust leak at head? Fuel pressure being off? If I can't get this figured out I will have to part with it and I've put enough time and money into it that I really don't want to say goodbye to it just yet. This seems like a fixable problem but maybe I'm just overlooking something? It seems like I must be missing something right in front of my face and am just not capable of seeing it. If I could just get step by step instructions to track it down that would help me emmensely, I kinda don't know where to start. Thank you.