My 1985 GSL need help!
 

I have a 12A. It was running fine. It suddenly start to lose power about 10 miles from home. I was able to make it home by holding the choke open. I don't have a clue what's wrong with it and don't have rotary smarts to figure it out. This problem occurred after the car had warm up. Any help is appreciated. I love this car but becoming frustrated with the car.

My guess is a vacuum leak. Check the hoses the connect to the carb. Will the car start and run after the choke is in?

It could be several other things including bad compression but let's not go there yet.

I second the vacuum leak possiblity.

It could also be that your fuel filter suddenly clogged from some debris that dislodged in going over a bump or something. With tanks this old, and depending on the car's history, things can get a bit gunked up in there.

Did the car just loose power or did you notice any stuttering, bogging, or the like?

Recently, I put a new fuel pump on from Advance auto. I did go over the carb for vacuum leaks and did not see any. I was crusing at 50+ MPH and it started to loose power. It did bog down when I tried to give it more gas. I pull the choke and held it open and that kept it going at 40 MPH.

Kinda sounds like a fueling issue. Why did you replace original pump,for same issue?You could have a defective new part, happens enough,some poor quality parts out there. What's the name brand of the pump,did it look like the original,assuming what you replaced was the original?
Have you replaced fuel filter recently,at same time you changed pump,have you looked at it recently. That is 1st thing i would do. Is it a clear filter,can you see any dirt/debris in there?
Try removing it and tapping it inlet side down on paper towels and see what comes out. It is possible that the fuel pickup in gas tank is clogged with rust/dirt/gunk starving fuel pump and carb of enough fuel to run properly. This is not an uncommon problem in these cars as old as they are now.
Where in Maryland are you located?

I'm located in Lexington Park (ST. Mary's County) Maryland. I can hear the fuel pump run but will check it tomorrow. When I replace the fuel pump, I was having what seem like fuel starvation problems. I pull the fuel pump and filter and they both were in very bad shape with rust showing in both. I drained the tank and replaced both the fuel pump and filter. I will pull the fuel filter and pump and examine them. I don't remember the name of the fuel pump. It was a name i'm not familiar with. Thank you.

That sounds like your fuel supply is the issue. If filter has rust/debris in it again,you'll need to remove fuel tank and inspect it. If it's heavily rusted it'll need to be replaced. If it's not too bad you can take it to a radiator shop for them to clean out,some shops offer a resealing service for the tank or you could do that yourself. Inspect the lines that go in the tank for rust,if bad they must be replaced too. You will have to flush the fuel feed and return lines to purge them of gunk,flush out the pump best you can and install a new filter.
There is a possibility that what you found in the filter/pump has made its way into the carburetor as well.

Thank you. I will inspect the tank as soon as the weather breaks because I don't have garage.