this sounds like a lack of fuel and could be a lack of fuel pressure from the electrical pump at the tank.
If the connections to the pump are corroded or damaged then the pump could stop at any time or could not be running at full speed. Check that its relay switches in and out and the relay contacts are clean and bright – replace the relay if in any doubt and do the same for the fuse,
Ideally measure the pressure at the injectors and if this is low check the pump as described and also consider changing the fuel filter as if this partially blocked this too will reduce pressure.
Hi Matt, yes it could be a fuel problem but I am also getting a warning sign on the instrument dash board which lights up when I try to gain more power.
I had the battery disconected just before the problem started could it need a fault code clearing?
The car will accelerate when pushed but when the revs drop thats when the lack of power and the warning sign shows.
Could it be a vacuum problem.
I will change the fuel filter to see if it is a starvation issue.