Has anyone had an opti go out with out warning?

The other day I drove my 93 Z28 to work and had no problems at all. It started fine and ran fine, no issues or hints anything was wrong. Before I got off work there was a heavy thunder storm (lots of rain, car not submerged). When I left work the car would turn over just fine but would not start. The opti, coil and ICM were all replaced less than a year ago, (maybe <3000 miles) I read a bunch of posts and did a lot of research/trouble shooting and I just dont want to accept that its the opti.

Fuel psi is good but there is no spark at the plugs. Any help/advice would be great. Thanks in advance!

Matt

 

No spark at the plugs you say, but is there spark at the coil wire?

 

Thats the part I am a little confused with. I tried to get a spark by disconnecting the coil wire from the coil (vs from the opti) and tried to get a spark but there was none. Using the voltmeter, the voltmeter showed there was current coming from the post but still, no spark. I thought there should be a spark if I could arch it with a screw driver or something.

As you can guess, I am not very good with electrical stuff.

So Im not sure.

 

Put a wire on the coil terminal and see if it will arc to ground (like you would do with a plug wire). If there is spark from the coil and not plug wires, your rotor is probably trashed.

If no spark from the coil, read the opti diagnosis sticky at the top of the forum page. It would not hurt to check fuses, too.

You'll probably blow up a multimeter if you try to read a spark from the coil.

 

I did wrap a wire from the coil post to a ground and no spark. I checked the fuses and there are none blown. I will read the sticky at the top again and see if it sheds some light. Is it possible for the opti to just stop working like that?

 

So I read the sticky and I can rule out the ICM and the coil (I think) since I had them both tested at the auto parts store.

 

The Optical cam position sensor in the Opti can die an instantaneous death. The rotor can fall off, intantaneously. Totally possible for an Opti to work well one minute, and fail the next.

Have you tried scanning the ECM for codes? On your 93, you can flash the codes on the SES light, by shorting the ALDL pins:

Courtesy of Shoebox:

http://shbox.com/1/dlc2.jpg

 

No, I have not scanned it yet. I will have to check it tomorrow since I had to leave it at work. I didnt even think to check it until I got back from trying to figure it out the first time.

 

Not just possible, it happens all the time. Getting it wet probably killed it, they really don't like water.

 

Even though it rained hard, it didnt get wet. I learned about how they dont like water the ard way..

 

I checked the codes and this is what I got.

12-Diagnostics working
16-Low Res pulse
26-EVAP purge control ( I knew I had this one)
46-Pass Key Circut

So what does that all mean? Sounds like the opti (TC 16) but then with (TC46) could it just be a wireing issue?

Again, thanks for all your help!

Matt

 

The 16 can't come from the ignition key. But wiring from the OPTI to the PCM, definitely. The pass key circuit problem is easily remedied with a $1 resistor. You cold try a new key that might correct the problem but usually it's a combination of key and ignition switch contacts worn. If you don't mind doing away with the pass key, the resistor is the way to go.

 

How would I go about getting rid of the pass key with the resistor?

Is there a way to check the wiring from the opti to the PCM? How hard/expensive is that to fix?

 

You may have more than one problem. Since you don't know how old any of the codes are, you might reset the PCM and see what comes back. A code 46 from the VATS will keep the car from starting. It is not a problem with the key (not something you can fix with a resistor), but a loss of the signal from the VATS module to the PCM that allows injector operation.
If you want to read up on VATS, go here.

 

OK, I read about the VATS and like I said earlier, the engine will turn over but it just wont run. I will try a new key, just to see what happens. If the VATS is not working properly, will that cause no spark at the plugs too?