JGuy07

Checking lines and noticed I have an odd setup on my engine. On the driver side of the intake where the PCV Valve and pipe are suppose to be located and the vacuum line for the opti are, instead of having two separate lines going to where they are suppose to go there is a short hose that just connects to both ports.

So, there is no line from the pcv valve running to the port under the intake below the TB and there is no line running from the intake vacuum source for the opti to the opti. Instead, a short hose connects both of those ports together.

The port under and below the TB for the PCV Valve line appears to be blocked whether this is how it suppose to be or not I do not know. And I am unsure of how the opti is setup or where that opti vacuum line is suppose to go. Can someone fill me in on what the deal with this could be?

shoebox

What you have is what is supposed to be there. It's different pre 1995. You don't have a vented opti, so there are no vacuum lines to go to it. The PCV has a u-shaped hose.

JGuy07

ok, thanks for clearing that up.

Injuneer

This is a 94 with the vented Opti conversion vacuum line tee'd into the EGR vacuum line.

http://www.injuneer.com/images/photo.../dOptivac1.jpg

importkiller94

If u still have the 94 emission sticker on your radiator support it should show you that's the way its supposed to be set up

JGuy07

How would/could you visually(or otherwise) verify whether or not the opti is vented or not?
***disregard question, found answers on shoebox's site. Thanks.

What are the actual pro's and con's of running a vented opti over the traditional non vented for the '94?

shoebox

Cons are cost and effort involved to convert.

Pros are less internal contamination by ozone and moisture and theoretically, longer life.

JGuy07

Guess I can at least look into that option...

shoebox

It's way more than just the opti and some vacuum lines. That's what you have to factor in.

Besides the optispark itself (GM p/n 1104032), you need:

• 95 or later timing cover [1995 front cover (includes round seals) GM p/n 12552426-now discontinued]
• late model or aftermarket cam (or have your cam modified by drilling the hole in the front to the proper size [.500"dia. X 1.0625" deep] and a longer dowel pin added (pin needs to protrude ~.650" from the nose of the cam)
• 95 and later optispark electrical harness GM p/n 12130319 (or aftermarket equivalent)
• optispark vacuum harness GM p/n 12555323
• vacuum fitting [GM p/n 14082470] or "tee" to provide vacuum for the opti
• 95 or later timing set components (or at least the cam gear) cam gear (GM p/n 10206039), crank gear (GM p/n 10128346), chain (GM p/n 10128485)
• timing cover gasket GM p/n 10128293
• water pump gaskets [2] GM p/n 10128343
• intake manifold gaskets if you are pulling the cam GM p/n 12524653

Or you can put an MSD cap/rotor kit on it and essentially have a vented opti. They come with their own and similar venting system.

pgerst

I believe both MSD and Dynaspark both make spline style optis (1994) that have the vent system retrofitted (more than just a cap and rotor.) There have been some issues with Dynaspark (mine crapped out recently) that are related to the optical sensor; not sure about MSD reliability. General consensus is the GM optis are the "best" to the extent any optispark could be referred to as "best"; to use a GM opti you need all the 1995+ parts.
http://www.summitracing.com/parts/MSD-8381/
http://www.dynaspark.net/advantage/

Injuneer

http://www.corvettefever.com/howto/16758/index.html