What are these?

[RonnieT]

I have a 2000 GMC 4x4 1500 3 door ,has 157,000 + miles, always taken care of and put on new parts when needed was wondering if anyone can tell me what these 3 items are and their functions on the 5.3L  engine.

   These are one top the engine with cover removed, I know the TPS and the MAF sensors and the Pressure regulator but  was wondering abut these , see the 2 pictures.

 One looks like a solenoid above the TPS and the one  behind it to the left  on the plenum? the 3rd one is under the firewall cowl at top rear of engine. 

Ron

 

 

[CamGTP]

The first picture, the part with the hose connected to it is the EVAP purge valve. The part that is bolted to the throttle body with a 2 wire connector is the idle air control valve (IAC).

 

The second picture is the MAP sensor.

Edited October 2, 2021 by CamGTP

[RonnieT]

thank you !  Would either of these be the cause of any acceleration  hesitation on take off from a standing stop and not every time, only occasional? (No codes on scanner)