hi gang need some help really stumped!

(1987 3rd gen) cars had it's first drive in 15 years and it's gone abysmally, rebuilt carb, new spark plugs wires, alternator, ETC. now I'm by no means a mechanic but trying my best through the service manual and YouTube, my problem is it was idling fine around 2k rpm before doing brake line so obviously could not see what the rpm would be underload. have it sitting at 2k rpm and drops to 1k ish rpm in gear but idle will bounce a 100 rpm back and forth. on the drive every time i would come to a stop it will stall out. I'm on the lines of thinking I have vacuum leaks and bad timing? used some brake cleaner around carb gaskets and valve cover but no change around that area.


UK based and no garage around wants to or feels confident working on a carburettor engine, any advice would be massively appreciated.

 

2k idle ? Are you sure your tachometer is right ? Could be a vacuum leak in the brake booster. But you might set timing first then adjust the idle and air bleed screws.

 

are we talking cardiac arrhythmias or cars!!!

sounds like a brake booster issue. You could un plug the vacuum line to it and see if that makes a change. Obviously plug the line or things will be worse. I'd also check the vac line itself.

 

brakes feel quite good, seems like the booster holds a decent vacuum when in the morning cold start after leaving it a night. I'll plug the line, was thinking about one of those smoke machines to see if lines have perished?

 

The smoke machine should be useful unless if it's an external leak. If it's an internal carb issue it won't help. Booster can leak in multiple spots. Around where the booster and master connect, the perimeter and where the brake pedal rod inserts. Disconnecting and plugging vacuum lines temporality would be the first step. You could try smoke after.