Crusin'
Camaro Z28 problem
By GREG ZYLA

Q: Greg, I have a '94 Camaro Z28, and it has started missing badly. I have checked all the plugs and wires, but everything seems to be OK. I want to keep this car, as I feel it will be a classic one day and it only has 28,000 miles on it. Could it be a short, camshaft or other ignition type problem? Please help. Michael, e-mail from Washington

A: Michael, I can tell you what it most likely is, as I had the same problem with my '94 Trans-Am, and my car has only 14,000 miles on it. The 1993-94 Camaro Z28 and Firebird Trans-Am models, both powered by identical LT1 Corvettestyle V-8 350 engines, suffer from what is called a "non-vented Opti" - the optical spark GM distributor, located near the water pump area.

These units cannot dry out moisture if it gets in there, thus

they are called "non-vented." My Trans-Am started acting up after I drove in a four-hour rainstorm; the Opti had gotten wet somehow, and that was it. It could have been the water pump, too, leaking just a tad of fluid into the Opti.

From 1995 on, LT1 models had an improved "vented" Opti, which, sadly, is not interchangeable with our engines unless you change several other items, including the cam. So, I

put in a new, non-vented Opti, and it's been flawless ever since.

I also changed the water pump to an electric steel billet CSR unit that pumps 37 gallons per minute (they cost about $165-$175) and put in a Hypertech 160-degree F thermostat, as our models have a tendency to run hot in stop-andgo driving. I've had zero problems ever since, and the car's cooling abilities have increased greatly.

It sure sounds like the Opti to me, and if you move quickly you'll find them brand new on eBay for $250 to $320. Good luck.

Write to Greg Zyla in care of King Features Weekly Service, P.O. Box 536475, Orlando, FL32853-6475, or send an e-mail to letters.kfws@hearstsc.com.

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