302 idle problems - starts but won't idle

Rebuilt 302 engine with headers, crane cam, the bearings are all new (10 over on crank), new hyp. pistons (9 to 1), (30 over on cyl walls), oil pump, heads had to be shaved a bit as right head was slightly warped, new valve job, with new rod guides and hyd. lifters. It is a ford CFI throttle body with a computer control module. It will start and I can keep it running if I keep throttling the gas, but will not go to an idle no matter how warm the engine gets !
I replaced the Air temperature sensor on the engine, as it was showing 2.7 volts with a cold engine, while the coolant sensor was showing 3.2, but to no effect. If I disconnect the air temp sensor, the engine will start and run at around 3000 rpm, with the occasional backfire before I shut it off.

Any ideas what might be causing this ?

Thanks.

By the way, please tell me if I'm posting in the wrong section, I assumed since it is fuel-injected this would be the most relevant place to put it in.

<font size=-1>[ This Message was edited by: siscrew on 4/14/05 11:54am ]</font>

I had a massive vacuum leak on under the intake from using Felpro race gaskets on a stock manifold following a rebuild. The port holes in the gaskets were way oversized, letting the intake ports suck air underneath the manifold. Wouldn't idle. Vacuum could be detected at the oil filler hole.

I would think that your timing is off. The engine will still run pretty good being a tooth off but it shows up in the idle and the backfire. Also the TP should be set about .98 and have an even rise as you push the throttle to 5 volts. Any skips or uneveness is a problem. You also have a throttle set screw which should be about half-way. Check your air bypass valve by diconnecting when the car is idling (or close) the engine should slowly stop. Steve

what are your cam specs?
[addsig]

IDLE AIR CONTROL..........

whoops ...you said CFI ....i dont know and will shut up
cause I am ignorant about CFI