Well Ive gone without a tach in my truck for about a year now, only about a month on my newer engine. My tach and fuel gauge got fried in an overchraging incident putting in previous engine. Ever since my charge light on my dash would be on. I got a dash from an 1980 from the junk yard. I put it in my truck and my tach works. Only problem is my trucks idling in between 1800 and 2000 rpm. I couldnt really tell before, because I have major exhaust leaks. I turned the air mixture screw, and got it to go down to 1500, but once it got below that, it died. Wont start now unless I pour some gas in the carb. It stays running on its own after I pour gas in the carb. Also I swapped in an 83 22r into my 81, I was told oil pressure sensor is different. Mine shows off the scale, Now my oil light is on in my dash, but it takes it a couple mins to come on. Help me figure out what is wrong with my engine. I am stumped. Maybe I have some vacuum lines wrong. Tell me where to start, please.

 

sounds like vac lines or maybe a carb problem