TransAmFever90

iTrader: (1)

Hey guys. I Have a 98 ls1 trans am. I have an odd fast paced solenoid/injector type clicking a few mins after starting up for my monthly warm up. I traced he sound to the drivers side. No vibration on the valve cover, head, or intake manifold. I can feel it strong in a little black box with a line coming from the fuel. It's vacuum. The other end goes to the throttle. I am guessing this is the canister purge valve? Whatever it is it's located on the drivers side valve cover up front near the coil pack. And it's ticking away. Engine speed does not change it. However my idle speed it fine. Thanks for any help.

RPM WS6

iTrader: (3)

Yes, that's the EVAP purge solenoid that you've found. It will make that sort of pulsing vibration (that you can feel) when it's operating, but you shouldn't be able to clearly hear it over the engine.

These aren't too expensive to replace and it's a pretty easy job, just be careful when disassembling it (you have to squeeze the ring at the tip just enough to allow them to be separated.) I had to replace mine due to a different reason (it was sticking open further than commanded and causing idle hang and surge.)

TransAmFever90

iTrader: (1)

So it is a pulse width modulated solenoid? I don't remember for sure seeing wires to it. Or is it a one way check valve that opens with vaccum? I know that's the source just wondering what causes it to click like it does.

RPM WS6

iTrader: (3)

Yes, it's PWM and the wiring harness does in fact connect to it.