Zfbod94

Yesterday I decided to put on my opti vent hoses. I switched to an opti 2 bout 10yrs ago and never attached the hoses. I never had a problem with the opti until about a month ago, when I removed the AIR system.

Whats happening is only when it rains, I believe some water is getting up in there and starts misfiring then runs normal when it dries up. This only started happening after I removed the AIR system, which may or may not have something to do with it. Meaning now that the AIR pump is not there, its not blocking any splashing that maybe occurring.

So I fixed all my vacuum connections at the manifold. Previous owner had rigged something up and plugged the port at the front under the throttle body. I returned everything to normal. I went to hook up the opti hose connections and ran into this.

[IMG][/IMG]


So where is the fresh air port? Am I just blind?

Zfbod94

Ok. I think I was given some bad info. My dad and I "replaced" the opti almost 10yrs ago. Well I just got off the phone with him, and according to him we only put on the vented opti cap and not the whole distributor. Well thats disappointing. On the other hand that means its the original opti and still running good at 140k miles. haha


So would I run into any foreseeable problems by leaving the vacuum hose hooked up and not running the fresh air hose? Possibility of anything getting sucked into it?

Injuneer

By connecting the vacuum and not having an air supply source -creating a dead-end system - you may find the Opti cap is pulled inward by the excessive vacuum.

There is also a current post on the LT1 Based Engine Tech forum which claims that the vacuum can cause oil and excess air to be pulled in through the bearing opening. The premise of that post is questionable (IMHO) because it measures the effect of vacuum leakage by dead-ending the system, and exposing the case to full intake manifold vacuum. But as someone else points out, the system will never see vacuum that high when operating with a free-flowing air supply system. But in effect, the author has replicated the exact system you are now operating.

Zfbod94

Yea Ive taken a few looks at that thread. Idk what to make of it. I agree that just the vacuum hose could pull in and dirt, debris, or water with no fresh air hose. Thats what I was worried about, especially when it rains. Pulling in water instead of it just being splashed on. Ill leave it on for the time being and see what happens.