Really Odd drivability problem :(
Thread Starter
Racer
Joined: Jul 2002
Posts: 437
Likes: 0
From: Rancho Santa Margarita Ca
Really Odd drivability problem :(
I have a 92 6 speed. On occasion at about 5000 RPM it will cut out like the rev limiter is kicking in. Today for kicks I just held it there. It would go cut out go cut out but never hit redline. 5 minutes later vroom right up to redline no problem. It seems to be easy to duplicate in first gear. It does not seem to be temperature dependant. I threw a new Fuel Filter and plugs at it for kicks and repaired both side leaking exhaust manifolds.No help.There are no other drive ability problems at any other RPMS. Anyone seen something like this ?
Thread Starter
Racer
Joined: Jul 2002
Posts: 437
Likes: 0
From: Rancho Santa Margarita Ca
Re: Really Odd drivability problem :( (bogus)
100k I don't think it has been replaced. Does it sound right that it would fall on its face or stumble. Cause it falls on its face when it happens.
Melting Slicks
Joined: May 2001
Posts: 2,143
Likes: 7
From: San Diego CA
Re: Really Odd drivability problem :( (bogus)
one of the first signs of a failing opti is a high rpm stumble.
check all your spark plugs and wires, too.
check all your spark plugs and wires, too.
Budget for a new OPTI. 100K is very good. How's the water pump?
You could start with new wires and plugs if they aren't too old.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Really Odd drivability problem :( (keekster)
Before you jump on the opti you might see if an exhaust shop can do a backpressure test and tell you if your Cats are healthy.
We had a very similar problem with our 99 Blazer. With the A/C on or under any load it wouldn't rev past 4k, under no load it would spin just fine. It got worse and worse until it just wouldn't spin past 4k ever.
I'm not saying it's not the opti, it probably is. But if you can get an exhaust shop to check your cat first you might save yourself a headache, the opti is a PITA. However I can do one now in about 3 hours on my car.
We had a very similar problem with our 99 Blazer. With the A/C on or under any load it wouldn't rev past 4k, under no load it would spin just fine. It got worse and worse until it just wouldn't spin past 4k ever.
I'm not saying it's not the opti, it probably is. But if you can get an exhaust shop to check your cat first you might save yourself a headache, the opti is a PITA. However I can do one now in about 3 hours on my car.
Thread Starter
Racer
Joined: Jul 2002
Posts: 437
Likes: 0
From: Rancho Santa Margarita Ca
Re: Really Odd drivability problem :( (Nathan Plemons)
I would suspect the cats also but it does not run out of power it just stops going. It feels exactly like when the rev limiter hits but it does it 1000 rpms to soon. It is also intermitant.Thanks for the replys :)
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Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Re: Really Odd drivability problem :( (John Row)
Yah, rats.. they just won't last past 100k... piece of junk ;)
Concerning the Opti longevity.... it's fine. No worse that any other ignition system on the market. Just because GM has crappy leakage on their water pump doesn't mean their Opti ignition system is crap.
Optical ignition systems work well. My ol' '85 Nissan 300ZX Turbo used the (mostly) same system for about 190K miles until the engine gave way. It works well.
You'll only hear complaints here in the forum from those who've experienced the typical GM fluid leakage which has seemed to have been corporate sponsored for the past 35 years. I guess GM owns a gasket company that has ailing profits.
Regardless... as long as an LT1 waterpump gasket holds out, the Opti will be just fine.... for a long time.
Concerning the Opti longevity.... it's fine. No worse that any other ignition system on the market. Just because GM has crappy leakage on their water pump doesn't mean their Opti ignition system is crap.
Optical ignition systems work well. My ol' '85 Nissan 300ZX Turbo used the (mostly) same system for about 190K miles until the engine gave way. It works well.
You'll only hear complaints here in the forum from those who've experienced the typical GM fluid leakage which has seemed to have been corporate sponsored for the past 35 years. I guess GM owns a gasket company that has ailing profits.
Regardless... as long as an LT1 waterpump gasket holds out, the Opti will be just fine.... for a long time.
Racer
Joined: Apr 2002
Posts: 389
Likes: 0
From: Micco FL
Re: Really Odd drivability problem :( (Dan Parker '96)
Fortunately 96 models have a properly sealed and vented Optisparks. Unfortunately, we (92 models) do not. As stated above, there is a chance the cats are stuffed or the wires are cross-talking, however the most likely problem is the Opti. If it is the Opti, and most of us believe it is you have to remove the waterpump to change it. Since a leaky waterpump is one of the main reasons for Opti failures it is recommended that it be changed at the same time.
Now that you are changing you Opti, most would tell you to upgrade to the vented (95-96) model. Here is a link that will guide you through the Opti change and upgrade.
http://www.corvettefever.com/editori...=text&id=16758
Good luck...
Now that you are changing you Opti, most would tell you to upgrade to the vented (95-96) model. Here is a link that will guide you through the Opti change and upgrade.
http://www.corvettefever.com/editori...=text&id=16758
Good luck...