I have 1988 c1500 the problem is when I drive it
won't pass 30 mph until letting off the gas and
again on 40 mph
Possible catalytic converter being plugged, or possible fuel regulator in the TBI. Get the vehicle warmed up and with the engine running park in a dark area, and look at the cat. If it is plugged it would have an orange tinge to it, it be hot glowing orange.
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