TbI to carb conversion issues

[89dnissan]

Hello, I have a 1989 nissan d21 with the z24I that I have converted to a weber 32/36 dgev carburetor and the truck runs amazing at an idle, but anything up past half throttle it's like it's popping and shaking and sometimes backfires out of the carb. I've tried getting a vacuum advance distributor for an 85 but it won't even bolt up to the motor. I've read that some people have rigged up a throttle positioning sensor to the carb but don't want to go out and spend 120 bucks if it's not going to work and seems like some haven't had any issues with the timing, I really could use the help on this one. Thanks in advance for any response