1994 Isuzu amigo hesitates at a certain rpm what might be wrong with it

I need to fix my truck

Is the Check Engine Light lit up?
What can you tell us about its maintenance over the past 3 years?

it comes on when it starts to hesitate

no maintenance for 2 years in a garage

You need to first find out why the Check Engine light is coming when the hesitation occurs.

Here’s how to pull the Diagnostic Trouble Codes on your OBDI Isuzu.

http://www.extreme-check-engine-light-codes.com/check-engine-light-codes/Isuzu-1983-1995-OBD1-Decoder.html

Tester

“no maintenance for 2 years in a garage”

Okay…then please give us the details on its maintenance during the 3 years before it was parked in the garage.

And the maintenance that was done as soon as it was taken out of the garage! I’d be concerned with old fluids, in particular gasoline, depending on how the car was stored.

As mentioned above, the first order of business is to check the diagnostic codes stored in the truck’s computer see why the CEL is coming on. That will give you something to work with. You can post the codes here if you like, maybe somebody here has experience w/that set of codes.

If I were to guess, I’d say it was something to do with the ignition system. Spark plug gap may have grown too big, distributor cap/rotor worn, or if you have coil packs instead, one or more of the coil packs burned out (often a result of a too wide spark plug gap), spark plug wires, crankshaft position sensor, something like that. But no need to guess, as the computer probably already knows and has posted the corresponding code.

If you wanted to try something as an experiment, try looking in the engine compartment with the engine running in total darkness. If you see any signs of visible sparks, that would confirm an ignition problem.