Like the title says sat for almost a year ran prior that just fine. Now it wont start. The only thing i can possibly think of is opti has rusted up inside since im getting no tach signal so the ECU dosent know its cranking.
Is this common? anyone ever hear of anything like this? i've chekced everything and i'm absolutly stuned at this point. At first i thought it was my MSD box so disconected that. Then i did the Shoeboxes test cranking with the Ignition module connector off and i had the voltmeter on it set on AC Volts and i was getting nothing while cranking out of any of the connectors. But i am gettin plenty of DC Volts while the ignition is on i think around 13v or so.

 

Do we assume you checked for spark and found none before you went looking into opti signals?

 

yes sir no sparky

 

Then use the DVM and look for the presence of 12 volts going to the opti and the low res and high res signals (both 5 volts) going back to the PCM from the opti. check from the pink/black wire to the red/black wire. As you slowly rotate the engine over see if it goes from 0 to 5 volts and then back to 0. Obviously power has to be on to do this.

Do that also for the high res signal from the same pink/black wire to the purple/black wire. Again as it rotates it will go 5 volts then 0 then 5 volts again.

If you have the 5 volt signals, you can assume the 12 volts is good.

And of course check the condition of the contacts for the 4 wire harness from the opti to the PCM and don't forget the connector about 2 feet from the opti as well.

If you have 12 volts going to the opti but either of the feedback signals is not present, you have either a wire problem or and opti problem.

 

are your sure your gasoline is ok? sometimes when it sits for more than say 5-6 months it separates and the pickup in the tank needs to be cleaned. just a thought.

 

You can't light the gasoline without a spark.

 

gas is fine it had beraly any gas in it, till i put 2 fresh gallons to get the car started, plus i dont have a pick up. Its an A1000 pump that is gravity fed from the tank with a Aeromotive FPR which kinda squicks when it builds full pressure and i do hear it squick and see on my aftermarket gauge that i get plenty of fuel pressure.
i pull the plugs out and they arent wet, I have a stand alone so in the veiw mode on the laptop im seeing that everything is working like it should, only problem is i'm not getting 125rpm while cranking as a matter of fact its not registering any rpm while cranking which leads me to belive its the crank position problem = opti.

 

what is DVM? sorry not very good in electrical department but will def try this.
thank you very much

 

DVM = digital voltage meter