Lack of power - Dewalt 18v Battery Hammer Drill Dcd950 Dc925

No power could mean a lot of things. Lack or air, lack of exhaust, lack of fuel, lack of compression, Timing. Which of these have you checked and which of them can you check

It is very possible that there will be a lack of power. Check that the cat converter is in good condition as they break up and block the exhaust. A faulty o2 sensor will also cause a lack of power as it sends the wrong signal to the ECM to keep the mixture right.

I had a similar problem with one of my vans. My problem was a clogged fuel filter. It was a result of water in my gasoline tank.

Black, sooty smoke? Lacks power? Coughs and hesitates under load? Hunts at idle? Lousy fuel consumption? It's running rich.

Good at start up then lack power under load,a plugged exhaust can do that.If there was a misfire that has been ignored the catalytic can only handle for so long. The 1994 Previa uses a vane airflow meter.so a torn intake duct can also cause lack of power under load,so check the air duct at the MAF to the intake and inspect for false air.

LACK OF POWER CAN BE CAUSED BY MANY THINGS.LIKE STOPPED UP FUEL FILTER. TRANSMISION SLIPPING DUE TO LOW FLUID OR CLOGGED FILTER,RESTRICTED EXHAUST SYSTEM CAUSED BY CLOGGED MUFFLER OR CLOGGED CATALYTIC CONVERTER.

Confirm ur fuel pump is working. Ensure ur pickup tube is not blocked. Then ensure u did not leave a rag or parts in the manifold tubes. Not laughing it happens. Is the distributor in the right spot. Etc etc. Did u rehook the alt up if removed . Is tje battery fully charged. And lastly is the fuel flowing and freash. Then recheck your work did u replace all parts right. Any air in the head gasket will make the fuel /air mixture off.
Good luck

check coil or powerpak

check out cat converter