95 dakota power issues

my mom has a 1995 dakota sport with the 2.5l 4cyl and 5 speed trans. About 6months ago the thing was having compression issues because of a bad head gasket, fixed that. About a month ago my brother replace a timing belt for her and since then It doesnt have any power expecially in 5th gear. I have even tried adjusting the timing via the distributor cap but cant get any improvments, I have been told that the timing is computer controlled, is this true and does anybody have any sugesstions.

First things that come to my mind is:

1) The crankshaft and camshafts are not matched to #1 TDC. Being off by even one tooth can affect performance.

2) Incorrect reinstallation of crankshaft pulley so that the markings are off true TDC.

3) Combination of 1) and 2).

Timing is computer controlled. Base timing is set by unplugging the coolant sensor and then adjusting base timing. Cam timing is probably off. This can be checked with a timing light if you have not already verified it is correct. Unplug coolant sensor and zero ignition timing by turning distributor. Point light at cam gear; the slot in the gear should line up with the rubber tip for the valve cover end seal at the top.