what do i do after no voltage at purge solenoid or vent solenoid?on evap system.

 

Did you command them to open with a Tech2 or equivalent bi-directional scan tool? They do not have voltage under normal operating conditions. Only when the PCM commands them to open do they get energized.

 

ya thats what i was wondering.the haynes book sez solenoid will not activate until fuel tank pressure exceeds 0.7 psi.But it sez test with ignition on not motor running.so i need a tech 2 to test ??

 

You have to activate the solenoids. I know that my scan tool can open them by command.

 

by the way this is on 98 4x4 4 door blazer

wonder if autozone rents scan tools ?

i manually put juice to the vent solenoid it seem to be in working order.couldnt blow or suck on it to see if air tight but i heard it working at least.

 

You should remove them to assess their seal. Knowing that they can move is only half of the equation.

I do not know if autozone will have a scan tool capable of bi-directional control.

 

i read in one of your older post to take it apart(vent solenoid)your seal was bad so you bought another one.i tried to dis asemble(vent solenoid)but could not get to the seal.but i sprayed wd-40 as u said to do in old post.i get your point maybe not air tight.i have been topping off my gas tank for several months now.just cause gas level sending unit bad.now reading in this sight it can be bad for the canister.could this be the problem?bed canister?and if so how do i test the canister.maybe its full of gas?

 

If you remove the charcoal canister and, when tipped on its side, gas pours out, the canister is full of fuel and is not capable of performing its function in the system. You would either have to drain and then purge the remainder of the fuel out of the canister or replace it.

 

thank u much.love blazer forum.not fixed yet but i will keep update on repair

 

oh ya.....i pulled hose of bottom of canister no gas came out not even a little..must it be tipped like you said?not sure what the inside looks like.if their was gas in it as much as i thought seems like some gas would of came out.i thought the thing would of been full for all time times i topped of the gas tank.ty again for your info i am now headed in the rite direction.