no power uphill

[damnzuki]

it starts fine, backs up fine, just no power going up hill. when i first start it it speeds up then slows down to almost a stall then speeds back up to about 700 rpm where it sit and idles i cleaned the catalytic converter out, and the owner had a new timing belt put on. it is a 93 16vengine with efi and it has a cracked exhaust manifold and no dash lights.