Ok I'm back
I found the mistake, look at the wrong page for1994 CADILLAC DEVILLE 4.9L v8.
Look on 94 instead of 98.
You are right. Thank you for catching the mistake.
Now let help Bigbill3975 to diagnose the problem.
Poor connection IAC motor. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Inspect the wire harness for damage, including; proper routing, broken insulation, rub through, or broken wires. A restricted air intake system. Check for a possible collapsed air intake duct, restricted air filter element, or foreign objects blocking the air intake system. Check the throttle body for objects blocking the IAC passage or throttle bore, excessive deposits in the IAC passage and on the IAC pintle, and excessive deposits in the throttle bore and on the throttle plate. Check for a sticking throttle plate. Also inspect the IAC passage for deposits or objects which will not allow the IAC pintle to fully extend. Check for a condition that causes a vacuum leak, such as disconnected or damaged hoses, leaks at the EGR valve or EGR pipe to intake manifold, leaks at the throttle body, faulty or incorrectly installed PCV valve, leaks at the intake manifold, a brake booster hose that leaks or is disconnected, or a faulty component that uses engine vacuum to operate.
Inspect the hoses you changed, make sure the clamps are tight. Make sure the small rubber ring around the IAC is there.
Let me know if you have questions.
Wednesday, September 23rd, 2009 AT 3:35 PM