Toyota Repair: Low Idle problem, intake leak, adjustment screw

Question
Good Morning-

My daughters 91 camry (3SFE engine)has a very low ldle.  It does not change when the A/C is engaged.  I suspect the IAC.  I have jumped the terminals suggested in the hayes manual and the vehicle almost dies, rather than idle up as it says it should.  The resistance check of the valve is good however.  The part is quite expensive and I wanted to eliminate any other possibilities before I try one.  Thank you for your time.

Donnie

Answer
IAC valve problems on early '90s Camrys are not common and it's probably something else, maybe an air intake leak, check the air intake tube from the air filter to the throttle body, they can crack and cause problems.
If you jumped terminals E1 and TE1 on the connector the engine should idle slower, this is normal because you are retarding the timing by doing this.
The base idle on this engine is adjustable, there is a small rubber plug(unless it's missing) on top of the throttle body, remove this plug, there is an idle adjustment screw in there that can be turned with a screwdriver to adjust the idle speed.
The idle speed should increase when the A/C is turned on and the compressor engages, this is controlled by the idle-up solenoid, it is also adjustable, it's located on the intake chamber and has some vacuum hoses going to it.