There is conflicting information about throttle bodies for the 2.5L Fiero. Some sources say that all GM 2.5L engines from '84-86 used the same throttle body. If you have a convenient salvage yard it is worth checking. We have not confirmed this and offer the information below from the "Hollander" manual:
'84 2.5L This throttle body is unique to the Fiero. No equivalents. Throttle body assemblies from '85-88 Fieros will not fit the '84.
'85 2.5L Throttle bodies from the following will fit:
Chevy Blazer S10/GM Jimmy S15 '85 2.5L S10/S15/GM Sonoma '85 2.5L
'86 2.5L This throttle body is unique to the Fiero. No equivalents. Throttle body assemblies from '84-85 or '87-88 Fieros will not fit the '86.
'87-88 2.5L Throttle bodies from the following will fit:
Buick Skylark '87 2.5L Buick Somerset '87 2.5L Olds Calais '87 2.5L Pontiac Grand Am '87 2.5L
'85-88: This throttle body assembly, made for GM by Holley, is unique to the Fiero. No equivalents. If the throttle body needs to be replaced, use one from a donor Fiero.