Black93lt1

Had a terrible misfire on my 93 z28 and went from changing the spark plugs, wires, fuel injectors, coil, and opti spark to showing this code and have no idea of how to fix it looking for a semi basic answer

Injuneer

DTC 16 is a problem with the low resolution pulse signal from the optical cam position sensor in the Optispark distributor. The ECM needs that signal to time the spark. But if the engine is running, DTC 16 is a stored code, not an active code. When DTC 16 sets, the ECM shuts down the fuel system, including the pump and the injectors. The pump will still prime when you turn the key to "run" or "start", but if the ECM can't find the cam position signal, it shuts everything down.

Has the engine ever just shut down on you while running? Have you had a situation where the engine would not start with extended cranking? Or is the only problem the severe misfire? Problem with DTC 16 is that is does not run on the SES light.

Did this code only show up AFTER you had done all the replacements you listed above? What brand Opti did you install?

Did replacing all the parts you listed above cure the misfire, and now it's just the presence of the code that you see as a problem?

If you clear the code (pull "ECM BATT" fuse for 30 seconds), how soon does it come back?

I've seen DTC 16 set if the ECM has a slight problem finding the low resolution signal when the engine is being started.

Could also be due to a faulty Optispark harness. Check the harness connector at the Opti for damaged pins, missing insulation, corrosion, or a missing retainer clip. Also check the gray 4-pin connector on the bracket on the passenger side of the intake (assuming the 93 is the same as the 94).



If

Black93lt1

It shut down on me after starting up after a weekend of not driving and i had a friend that blew the battery and burnt out the starter. Replaced the starter and found out that it wouldnt start but it was cranking. Sprayed a little throttle body cleaner in the tb and it wanted to start so i replaced the injectors. Started up and had the severe misfire under load. Moved to checking the wires and 1 of them was spliced by the belt so i replaced those as replacing them I noticed i had a lot of oil all over the front side of the block. Took the water pump off too see more and the oil was just below it. Took the harmonic balancer off and opti off and a seal was leaking. Replaced all the seals to the front timing cover. Opened up the opti to see if it was sucking in the oil and it did a little bit so just cleaned it up and put it back on along with everything else. Attempted to start it and there was nothing so i tried the old paper clip trick and it pulled up this code. Buying a new opti tomorrow but was wondering if that would even be the issue

Injuneer

If it won't start, and it has DTC 16, it's fairly certain the Opti has died. That assumes you have ruled out the harness. The only thing that can set DTC 16 is the low res pule signal from the Opti.

There is also a high resolution pulse signal that would set DTC 36. When that sets, the engine should still run. The ignition timing will not be as accurate, but it's nothing you would even notice, particularly on the 93 with the batch fire injectors. 94 and up with sequential injection also times the injectors off the Opti signals.

Black93lt1

So I should get a brand new opti?

Where is a good place to order a good one for a fair price?

Black93lt1

And would a simple replacement of just the cap and rotor be useless?