engine running like shit

hey guys, i got a 94 pup. its the 2.3 carb motor. I CANNOT get this thing to idle right. ive replaced vacumm lines, cleaned the carb, ran cleaner thru it, new plugs, oil changes, air filters. Ive adjusted it over and over, and tried everything i can on it to get it to just idle right.

Can anyone help me, or tell me what i might need or dont need. Just to get this thing runnin good.

It idles from 1 to 2000 after i drive it for a little while, back and forth, 1,2,1,2,1,2, and sometimes itll idle at 600 and just barely wants to die. I dunno.

sounds like a crank sensor?? if isuzu's are equiped with them...my jeep did that and it was the crank sensor

crank sensor eh...weres that located, if it has one??

sounds like you have carb problems the 2.3 is known for that thats why most people go with the weber carbs

its probably the intake manifold gasket. thats a common problem on these trucks. i've had it with all of the zu's ive owned. to check it let the truck idle and spray some carb cleaner around where the intake meets the head if idle picks up then theres your problem. the gaskets leaking making the intake lose vaccum.

any progress?