Does the vented Optispark need vacuum to function?
Thread Starter
Cruising
Joined: Feb 2023
Posts: 11
Likes: 1
Does the vented Optispark need vacuum to function?
I'm in the process of replacing the vacuum tube to the optispark, but pulled it out before realizing how much of a pain it is to plug back in. From what I read I thought it was just meant to create airflow for the venting function, and not necessary to work, but when I went to start it before hooking the hose back up, it turns over without starting as if the optispark isn't working. No codes thrown and I'm hoping I don't need to tear everything out just to plug a vacuum tube in.
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
The vented opti is to keep airflow through the opti to keep it dry.
It does not stop the opti from working. It is only to keep airflow through the housing.
It could be important to hook it back up. It was an improvement to help the opti survive and without it there is an additional path for water to enter.
good luck
It does not stop the opti from working. It is only to keep airflow through the housing.
It could be important to hook it back up. It was an improvement to help the opti survive and without it there is an additional path for water to enter.
good luck
Drifting
Joined: Feb 2017
Posts: 1,274
Likes: 399
From: Tacoma WA
2024 C4 of the Year Finalist - Unmodified
As stated by QCVette the airflow was there to prevent moisture buildup within the newer opti design and does not affect function.
Your car not starting is not related to vacuum hose not being connected!
Did you do any other work on the car while trying to replace the vacuum hose? Did you inadvertently bump, dislodge, or disconnect anything else while getting to the hose? It all boils down to fuel, air, ignition so one of those three is not working. Take one component at a time to troubleshoot the non start condition. Follow the FSM and you should be able to find the issue causing the non start condition.
Your car not starting is not related to vacuum hose not being connected!
Did you do any other work on the car while trying to replace the vacuum hose? Did you inadvertently bump, dislodge, or disconnect anything else while getting to the hose? It all boils down to fuel, air, ignition so one of those three is not working. Take one component at a time to troubleshoot the non start condition. Follow the FSM and you should be able to find the issue causing the non start condition.
