Hesitation, is this fuel related?

[Blue_bags]

Okay here I am again. Another problem with my 88 toy 4x4 with the 22re. Lately, when the rpms are kinda high, like before a 2-3 shift and a 3-4 shift, or just when the revs are up there. The check engine light blips on and off, on and off, on and off, and the truck kinda like hiccups. The higher I keep the rev going, like If I'm in 5th gear already and I lay on more gas it won't want to go any faster. It just keeps on like "hiccuping". Im wondering if this is more a problem with the fuel system, or would this have more to do with the transmission?, or I have a feeling its the fan belt slipping? because this hiccuping is similar to how it felt before the fan belt broke? not sure though cause the fan belt I replaced it with is not broken....well im not too sure if my description is helpful, but any help will be appreciated. Thanx

[DM_Rok]

Have you checked the fuel filter yet? Based on your description, sounds like you're losing fuel pressure or you have an ignition - based misfire.