What are the symptoms of an Opti going bad? My 94 Z28 is hesitating bad from around 1200-2000rpm. It is fine for the first few minutes after startup then gets bad as the motor heats up.

Thanks!

 

Yep, that sounds just like a bad optispark. I had the same issue. The car would start right up, hit operating temp, and then hesitate like crazy with hardly any gas. I did everything else like fuel filter, injector cleaner, new coil/module, plugs and wires, hoping it was something else. Eventually it just stopped altogether and i found where my leak was.

The halmark symptom of a dying optispark is extreme hesitation in the engine when gas is applied, the reason being because an optispark goes when leaked on by the water pump sitting directly above it. Not to mention, the water pump leaks more when under load, hence why the more RPM you have, the more hesitaiton there is.

Here's what to do to be sure it's your opti and not something cheaper and easier.

-Before you spend any money, get underneath the car and check for leaks around the water pump while and after it's been running at operating temp. There is a A.I.R line that runs just underneath the crank pulley and up to each exhaust manifold. Clean the A.I.R line as best you can and watch for drips (mine had a steady drip days after it had been shut down). If no leaks are obvious, get a small flashlight and check above it. Any excess moisture is an indicator of a leaky water pump.

-Occasionally, the plugs and wires can act up with age. Change those regardless of the optispark's fate. New plugs and wires will never hurt you (unless you isntall the wrong ones).

-Check the connections to the ignition coil/module assembly; those parts can also act up when they get hot and are old. A new delco module and coil will run around $100.00

-Connections to MAF sensor (change as necessary but have a dealership fix the wiring harness if the problem lies in there).

-Change the fuel filter also. That will be between 8-17 bucks depending on what brand you go with.

Hate to say it though, from what you're saying about the car's behavior im pretty sure the opti is shot. The good news is, however, even if you replace everything listend above the car still acts up, once the opti is replaced your car is going to run cherry. Have a dealership install the opti and water pump. They guarantee the work so you know it's done right the first time. If not, the bill is them.

-Hope this helped

 

Thanks for the reply. Honestly if I had of known about the Opti issues these LT1 cars have I probably would not have bought it. I will check those things first. The plugs and wires were done less than 5000miles ago when I got it, so I know it is not them.

 

Does your SES light come on? I have a bad opti (waiting for the money to replace it) and the car will hesitate and even die for a second then the SES light will come on. I have a code 36 and occasionally code 16.

 

Nope the light has never come on. I also tried pulling the plug on the MAF to keep it in open loop mode as I had seen mentioned in other posts and it was still bogging bad with throttle between 1200-2000rpm..

 

Well, at least you can check off one possibility. A new MAF can run upwards of 500 bucks, so at least you saved a bit of cash. You mentioned you got the plugs done. If a dealership did them then this isn't your issue, but the plugs have to be a certain heat spec to function properly in the engine Even if the gap is correct, a plug running at the wrong temp will cause hesitation. Where did you have the plugs done? Did you find any coolant leaks around the water pump and opti?

 

Check this sticky
https://camaroforums.com/forum/lt1-lt4-tech-9/lt1-faq-tech-25386/

 

The plugs were done at a dealer last summer when the car was doing the same thing. New plugs and wires then fixed the problem, but now the hesitation is back. Around the Opti and water pump it is completely dry. I was going through the old reciepts from the previous owner and this car has had a history of hesitating a few times. fixes were plugs cleaned, distributor cap and module(is that the opti?) plugs cleaned again, and new plugs which I did. Wondering if the plugs are screwed again for some reason???