85 Camaro 305 TBI runs great at cold startup and after warmed up good. Runs rough and hesitates in between. Changed Idle Conrol Valve, Plugs, PCV, Air & Gas filter. Whats next.

 

Coolant Temp Sensor

What year car was the TBI motor out of?

 

1885 Camaro Z-28, engine replaced V-6
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The engine is a rebuilt 1985 305 TBI. Replaced V-6.

 

There was no TBI 305 in 85.

What we commonly call TBI was introduced in 88. There was an earlier system that had 2 TBI units, called CFI, that was used only in 82 & 83.

So whatever you've got and whatever it replaced, it isn't a TBI 305 from 85.

It's gonna be alot easier to properly troubleshoot it if we know what it really is.

What the PO of either the car or the motor told you it was, is insufficient evidence.

What is it, really? Does it actually have TBI on it?

 

I finally hunted down the person that did most of the swap on the 85 Camaro Coupe and he said the engine was a Rebuilt 1988 305 LO3 TBI with LO1 head.
(Valve covers have center bolts.)
Hope that helps.
Thanks for the help. I'm new at this.
The Camaro is in great shape and would like to get it running like should.