1991 Mighty max

[LSR Mike]

1991 should be fuel injected...ECU?

[gvallo88]

Maybe loose connections on battery cables, could be corroded inside the terminals. Change them both, ground and power, be sure to clean the grounds until shiny. After that, look at changing the ecu or the little black cube near the distributor- ie ignition module. or TPS. thats my guess. Good Luck