tbi 350 engine running weird

Put a tbi 350 with wiring in my 81 chev truck rolls over a lot before starting, then runs weird as in idles weird then, does like a surge up and down from 600rpm to 800 and so on then seems to run okay and I think it is done with.. Next day restart.. and it either runs good or runs worse and the same thing. No check engine light, new intake gaskets, throttle body gasket, o2 sensor temp sensor.. Any advice ?.. It almost seems like the computer is forgetting it's mprogramming day to day...or timing is constantly trying to adjust itself.. I have tried 3 computers etc.. All the advice I get is buy a scan tool (which without check engine light on) is a waste of money.., yes the check engine light is working.., 2. I get the "drive it as the computer needs to tune itself" I heard this motor run before I bought it and it didn't do this at all.. Thanx in advance.

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Chevrolet
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Chevrolet

IS the computer hooked up to live power all the time? Also it sounds like a problem with the ICS (Idle Control Solenoid) because a problem with it can cause RPM to hunt around for a while at a idle.

----------------- TheSnoMan.com

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SnoMan

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Chevrolet

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Chevrolet

This will not effect idle unless it is stuck open. ECM fuse should always be hot. Also a vacum leak can cause a erratic adle as well and ECM has to monitor engine RPM as well to control ICS. Try starting it up with ICS unplugged and see if idle speed is stable or not.

----------------- TheSnoMan.com

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SnoMan

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Chevrolet

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