EATC Vacuum

[toolbox107]

I don't have vacuum coming out of the black line to the EATC, do anybody know where the black line goes under the dash and on the fire wall or is there something I need to replace to get vacuum. :confused:

[fastblackmerc]

The vacuum line eventually goes to the tank (flat black square box) located under the hood, on the driver's side fender liner, behind the washer tank.

[Blackened300a]

When I had this problem, it was the 2 check valves on the fire wall. I wouldn't have any vacuum to the EATC and for $10 for 2 new valves I had more then enough vacuum.

[toolbox107]

When I had this problem, it was the 2 check valves on the fire wall. I wouldn't have any vacuum to the EATC and for $10 for 2 new valves I had more then enough vacuum.

Can you please tell me where these valves are located on the fire wall and are they called by another name so I know what to ask for at the part store.:confused:

[fastblackmerc]

They are called "vacuum check valves". Follow the vacuum line from the tank. the valves are in-line.

[RF Overlord]

Try this: Start the car and let it idle for 10 seconds or so. Stop the car. Pull the hose off the vacuum reservoir (square plastic box directly on top of the driver's-side wheel well). You should hear vacuum escaping. If not, you need to follow the under-hood vacuum lines and find the break. If you DO hear vacuum leaking, then either it's the check valves as Paul said ^^^ or the break is under the dash.

[burt ragio]

What does the vacum & valves do to the ETCU ? What is in the black box behind the washer fluid box ?

[RF Overlord]

burt, all the air flow controls except the blend door are actuated by vacuum motors. The check valves prevent loss of vacuum in the system when the engine is under load (accelerating) and manifold vacuum is low. The black box (vacuum reservoir) contains nothing...it's just a place to store vacuum.

[toolbox107]

Thanks for the info but the problem was the vacuum line from the check valve going inside the car collapsed.