EDIT: Update... Car has been warming/drying in garage for 2+ hrs. with no improvement. I no longer believe that the Opti to be at fault.

So I pull my car out of the garage today and attempt to navigate down my snow-covered driveway. Getting stuck, I shovel like mad and leave the car running to warm it up. Having cleared the path, I get in the car and attempt to resume my journey. Spinning the tires a little to get up over a pile, I hear a loud BANG and my "Service Engine" light comes on. The car sputters to a stop with my right foot about a quarter depressed. I attempt to restart and it idles poorly and dies completely under ANY throttle input. Following this, it cranks but will not run.
I get gasoline and put it in the tank, as I was very low, in the hopes that this will solve the problem. Again, it cranks but will not run at all. I pull all relevant fuses for fuel pump, injectors, ignition, etc., and all are good. I crank some more and then run to the back and stick my nose in the tailpipe. Smelling fuel, I figure I must not be getting spark. I pull the #6 ignition wire, put an old plug in it, and crank while a friend watches for a spark. It sparks, but is "weak."
I have since pushed it into the garage and turned on a heater, thinking I might have ice/snow in the opti?? This feels similar to when I got water in the opti... After drying, the car ran perfectly that time.
The only thing I can't figure out is I don't see any snow or moisture around the area of the opti. :confused: If it helps, garage temp. is approx. 45+, outside is 25. Any other areas to check?
Any assistance is much appreciated. Thanks in advance.


[Modified by Knight Ryder, 7:54 PM 2/15/2003]


[Modified by Knight Ryder, 9:55 PM 2/15/2003]

 

Knight Ryder,
I can't associate the loud bang with the other symptoms. I am wondering if maybe you broke the wires to your O2 Sensor(s), or maybe knocked the connector of of one of the knock sensors. The Opti is oriented way too high for the snow to have caused an immediate problem like you have experienced (although the performance symptoms are very similar). Let us know what you have found. If you really think it is a wet Opti, try placing a hot drop light under the Opti and let it dry out.
~ Purp :seeya

 

Purp,
Would a broken knock sensor/O2 sensor wire prevent the car from running at all? Could the "bang," which came from under the hood, be the result of a dead knock sensor (or wire) causing the engine to advance into pre-ignition? Or will the programming prevent such an advance? I am concerned about that sound, but cannot find the source. Everything seems OK mechanically, so I assume it is sensor/electrical, etc...
Thanks again! :seeya

 

Have you checked your ignition coil? If the coil is weak it can allow the car to pop and sputter. Why don't you put a spark plug right on the coil wire and see if it still seems like a weak spark. If it is then the coil is your problem, if it's strong there then the problem lies in your opti. Shouldn't take 30 seconds to check and might save you a headache.

Just to justify, it has happened before. Peter (drive it) here on the forum was in town having trouble with his car. He called me up and he limped over to my house. We finally tracked it down to the coil. We thought it was either his MSD igniton or the coil itself. We disconnected the MSD and it wouldn't run at all. It sparked but it was VERY weak. We put the MSD back and it would run again although badly. We replaced the coil and everything was alright again.

:cheers:

 

Here's a long shot. Since you were trying to drive on a slippery surface and did go through the pile of snow, could you have affected your traction control? Maybe it somehow got stuck in the active/on mode and it's trying to kill or cut back your engine. Like I said this is just a long shot. Dan :confused:

 

Knight Ryder,
My 92 LT1 Coupe has two O2 Sensors. When I bought it, one wire was broken and it ran terrible.

~ I still can't associate the noise with the poor performance. I can usually figure this type of stuff out, but this one has me a little baffled. Nathan has mentioned the coil, but unless you compacted it with snow and/or ice ~ I find it to be an equal long shot. A stock coil is relatively cheap and easy to replace. I am not really into parts changing for troubleshooting....... unless it is cheap.

There is a chance that the snow/ice might have knocked a wire off your Opti, or broken a wire. Hang in there, you will get it fixed.

I can't remember if your Vette is speed density or not. If you have a MAF, I would also suspect that something happened to the connector or the wire. I know that it is way high in the engine compartment.

If you know someone with the same year, why not try and talk them in to some parts swapping. Cheap and effective! :hurray:

~ Purp :seeya

 

I just ordered a scan tool and I am going to pull the code it registered just before it died. I will let you know what I find.

 

I'm having the same problem and I live in Alabama(NO SNOW) When my vette is cold it runs fine until it warms up ,,,,and then I'm stranded on the side of the road. I just replaced my optish$$ unit 12 months ago with a rebuilt. I have replaced this optish$$ 4 times since I have had the car in the last 4 years and have only put 30k miles on the 92 vette. I think GM needs to take responsibility for this piece of SH$$ optispark unit. :mad

 

If you keep replacing the opti and it's not fixing the problen then wouldn't that lead you to believe that it's not the opti causing it?

Please do us all a favor and not whine about it. If you hate it so much then buy a car that doesn't have an opti.

 

It's almost certainly NOT the knock sensors. If they are bad, teh engine will run in 'open loop' and lack top-end power, but will still handle OK in city traffic.

 

Your right ,,,my bad for whinning,,I did'nt mean to vent my frustrations. I apologize..

I was also thinking that it may be something else. I have replaced everything in the electronics firing system except the ignition coil module. The DI, I replaced in January of 2002 and it only has about 4000 miles on it if that. My scan tool say code 16 which is DI system fault...Guess I will try the module next..

Ohh well ,,,again my apologies