The thing to do woule be to give the engine a proper service and have the injection timing properly set. It's set by measuring plunger lift at TDC for cylinder 1 or 4, and should fall in the region of 1.0mm +/- 0.03mm. Check to make sure if you can get a more exact figure, but this is the figure for a Zexel or Diesel Kiki distributor axial piston injection pump for the Toyota 2L and Mitsubishi 4D56 engines. These pumps are to my knowledge, based on the Bosch VE family of pumps.
Also, have your injector nozzles checked for cracking pressure and spray pattern. Any good diesel service workshop will be able to do this.
Second thing to do is to increase the fueling a little bit. I've increased it a bit on mine, and the engine goes to around 5500 RPM if I let it rev. It does smoke a little bit, but acceleration has improved. Be advised though, that you will have to pull yourself back a bit from flooring the accelerator if you want to have good fuel economy. If you drive it with the foot to the floor, you'll not be happy with the fuel consumption.
The way I tuned my vehicle was to do a couple of runs while stopping and readjusting the fuel limit and then going for a full-throttle blast. If you fuel too much, it only belches black smoke and acceleration actually drops quite a bit. There's just one sweet spot where the engine smokes a little bit at full throttle. That's where it make the best power.
New oils and filters.
Hope this helps! Oh and by the way, a properly tuned 2C Corolla can chirp wheels on the 1-2 and 2-3 gearchanges.
