I recently bought an 85 2.8L and this is the first carbureted engine I've worked with so it's fairly foreign to me..

She starts everytime, I usually just have to crank it for 5-10 seconds then give it a little gas (unless the engine's warm). The issue is this rough starting and that it will randomly bog down either when I shift gears or step on the gas when it's around 2500 rpm. The previous owner said he rebuilt the carb and after that is when it started acting up and he's pretty sure it's something to do with the vacuum hose..

Like I said, I'm new to the carbureted engine so any info on how they run, the vacuum hose system, where to start looking with this issue, anything like that would be greatly appreciated. Thank You

 

That's the beauty of OBD & fuel injection! There are so many things it could be with a carb, and each one needs to be checked. Restricted jet, incorrect float level, restricted transition circuit, choke setting, choke pull off adjustment, unloader adjustment, acellerator pump problem, hot air intake system issue, a vacuum hose routing problem, ignition timing, vacuum advance issue. Carb kits are cheap, and they come with instructions and specs for setting it up. Might be a good place to start if you suspect a problem with it. Just need to take your time and make it hospital clean.

 

The previous owner told me that after they rebuild the carb (and at the same time replaced the intake gasket) that when they were hooking the vacuum lines back up they ended up with a valve without a hose and a hose without a valve but that the two didn't match up.. They hooked it up somehow and made it work but could this be the main source of the problem? Like I said I need to do more research to learn about how this whole system works and become more familiar with it lol

 

That could very well be the problem, but without knowing what it is, or where it goes, tracing all of the vacuum lines is what it will take to fix it. Some of the aftermarket shop manuals, (Chilton & Haynes) have vacuum diagrams, but I wouldn't trust either one of them. Best to use a GM factory shop manual. Sometimes you can find used ones on Ebay at a reasonable cost. It will need to be the exact same year, make, and model of your vehicle.

 

Sounds like a good place to start. I wanted to get a manual anyways ha. Thanks for the help and input