IAB Question....

[Philossifer]

Are all IAB's created equal? Should a Wells brand work the same as one I'd buy from the Ford parts counter?

The reason I ask is because of a problem that popped up when I installed the Wells IAB.

My motor is stock with a B-303 cam/5-Speed. I didn't notice there was a problem with the old IAB; in fact, the idle was pretty good except when I would turn on the A/C, then the idle would drop and run very rough. Turn off the A/C and it smoothed right out. (as smooth as a "B" cam can idle)

I removed the old IAB, tested it and sure enough, no clicking or movement of the plunger. I installed the new Wells brand IAB, didn't notice much difference in the idle but now, with the A/C on, the idle doesn't dip and holds pretty good.

The problem I'm having now is: after the engine is warm, the idle climbs to about 1100rpm. That's not really so bad but the problem is that the idle hangs too long before settling in at 1100rpm's. With the A/C on, it doesn't hang as long and settles in at about 900rpm.

So far, I've cleared the computer by disconnecting the battery for about 20 minutes, cleaned the throttle body, cleaned the MASS air sensor, adjusted the idle position sensor to about .99 volts as well as adjust the idle stop screw as per my Haynes Manual. (.010" feeler guage plus 1 1/2 turns in)

As far as codes, I get an 11 (system pass) with KOEO and 44 & 94 with KOER, these codes both have to do with the Thermactor Air Control System. I'm not running cats and no air pump. The O2 sensors and fuel pump are a few years old, the fuel pressure regulator is stock.

Other than the 1100rpm and hanging idle, the beast runs great.

Could it be the Wells brand IAB or is there anything else I should look at?????
Thanks,
Phil