1994 Opti spark question....
Thread Starter
Melting Slicks
Joined: Aug 2018
Posts: 3,127
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1994 Opti spark question....
I just bought a 1994 60,000 mile C4 and know that the Opti sparks that year are unvented. Can you put a vented one from a 95/96 in the 94 car? Any advice on this year car would be great. Thanks guys again for your time.
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From: Dallas Texas
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Yes you can. I believe Petris sells the opti's already vented for the 92-94 cars. But I'm sure someone will chime in with more knowledge than I have.
Drifting
Joined: Oct 2004
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From: Hawaii
92-94 Gen 1 Optispark, 95-97 Gen 2 Optispark are not interchangeable. A gen 1 can be modified to have a vent configuration.
https://www.nookandtranny.com/TechIn...#LT1Optisparks
https://www.nookandtranny.com/TechIn...#LT1Optisparks
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From: Kingman AZ
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From: Dublin CA
One thing that has not been addressed that should be is the water pump. In the wisdom of GM engineering, the water pump is located directly over the OPTI. Should this start to fail, coolant will leak out the weep hole under the pump and drip directly on the OPTI. Should you have the pump off or replace it, I would suggest that you drill out the weep hole a little and add a brass tube from a compression fitting into the weep hole. Epoxy around the fitting. Then install a vinyl hose to the fitting and using zip ties lead this hose down and away from the OPTI. So it the pump fails the coolant will be directed away from the OPTI. A modification that has less than $5.00 in materials that will save a $500(+/-) OPTI.
Thread Starter
Melting Slicks
Joined: Aug 2018
Posts: 3,127
Likes: 86
One thing that has not been addressed that should be is the water pump. In the wisdom of GM engineering, the water pump is located directly over the OPTI. Should this start to fail, coolant will leak out the weep hole under the pump and drip directly on the OPTI. Should you have the pump off or replace it, I would suggest that you drill out the weep hole a little and add a brass tube from a compression fitting into the weep hole. Epoxy around the fitting. Then install a vinyl hose to the fitting and using zip ties lead this hose down and away from the OPTI. So it the pump fails the coolant will be directed away from the OPTI. A modification that has less than $5.00 in materials that will save a $500(+/-) OPTI.
Excellent idea...thanks
Instructor
Joined: Feb 2007
Posts: 132
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From: CRYSTAL RIVER FL.
Vented opit
!992 Base
Several years ago I replaced my opti with a vented one that was set up for the "92. Kit provided the hoses, filter, and check valve with instructions for install.
Here's the problem. The Buick video shows the air inlet hose connected to the air inlet plenum "AFTER" the MAF sensor so idle is not affected because this is essentially a vacuum leak. The 1992-1993 do not have a MAF in the plenum. They have a MAP on the throttle body. This vacuum leak is not accounted for and will cause a slightly rough idle. You can test this by pulling the hose out of the inlet tube and plugging it with your finger. The idle will smooth right out. Just throwing this out there from my own experience. I've never come across a fix for this. Perhaps someone has.
Dave.
Several years ago I replaced my opti with a vented one that was set up for the "92. Kit provided the hoses, filter, and check valve with instructions for install.
Here's the problem. The Buick video shows the air inlet hose connected to the air inlet plenum "AFTER" the MAF sensor so idle is not affected because this is essentially a vacuum leak. The 1992-1993 do not have a MAF in the plenum. They have a MAP on the throttle body. This vacuum leak is not accounted for and will cause a slightly rough idle. You can test this by pulling the hose out of the inlet tube and plugging it with your finger. The idle will smooth right out. Just throwing this out there from my own experience. I've never come across a fix for this. Perhaps someone has.
Dave.
