Ok. here is the deal I have a 1995 Chevrolet C1500 305/5.0LTBI. My problem is that once I go out in the morning after it sits all night i start and it idles at 600-700. Then once it runs for 2-3 minutes the idle shoots up to 1600-1900. I have replaced the following
-Vacuum lines
-EGR Valve an Solenoid
-MAP Sensor
- Idle Air control
-Coolant Temp Sensor
- Throttle Body Gasket
- 02 Sensor
Literally everything but the intake manifold gasket!!
Dear god please someone have some advice. I'm running out of options, money and patients with this thing.
Could it possibly be my timing??
1995 Chevy C1500 305TBI

 

jacobrook22 Welcome to the forum..
I don't think an air leak isn't going to cause that much of a idle increase...
Have you watched the throttle actuator to see if it is physically moving on its own (have someone start it and you watch what happens under the hood)

I would want to establish that its not something mechanical first, throttle cable hanging on something, the cruise control causing it to happen...

You can try spraying the intake area with carb cleaner to see if the idle changes due to a leak, but I think something else is going on....

 

it is not your timing, if it starts and runs good

 

this may sound silly but maybe try and tighten your intake bolts