Runs but doesn't rev

So I'm trying to get my trusty Golf running after it's been stood still for a few years. The problem were having is that it starts first time with the key and ticks over fine but won't rev when accelerator is pressed down. Different engine, same problem. Its had a full service, new dizzy cap, ht leads and air filter. So is it the metering head or something else? 🙏🏿

Have you a whine from the right rear wheel arch?

Most acceleration issues are either air or Fuel or
timing.  

1. Does your Distributor Advance work?  
When it tries to accell does it stumble.

2. Mechanically does your Throttle body Butterfly or Carb butterfly move when you open the Throttle assembly by hand?

3. Have you validated the Fuel pressures are correct?

4. Have you validated that your frame to engine ground is the same potential as your Battery to frame ground?

Do my quick test for grounds.
Briano's Quick Grounds test. | Volkswagen Owners Club Forum

Briano1234 said

Have you a whine from the right rear wheel arch?

Most acceleration issues are either air or Fuel or
timing.  

1. Does your Distributor Advance work?  
When it tries to accell does it stumble.

2. Mechanically does your Throttle body Butterfly or Carb butterfly move when you open the Throttle assembly by hand?

3. Have you validated the Fuel pressures are correct?

4. Have you validated that your frame to engine ground is the same potential as your Battery to frame ground?

Do my quick test for grounds.
Briano's Quick Grounds test. | Volkswagen Owners Club Forum

Sounds like it's only running on the 5th injector mate

Sent from my SM-G975F using Tapatalk

Nothing runs well on dirty old petrol.
Petrol has a use by date and attracts water.
If you haven't removed the tank and cleaned it, put it clean fuel it will never run OK.
If crud is found inside it will be stuck in everything else.
Fuel pumps often seize after lack of use.