So i finished the project of installing a new MSD optispark replacement. Now the thing wont even fire. The engine will crank and crank but nothing. I pulled a plug a grounded it to see if it had any spark and nothing. Is there something im missing? I lined up the cam right to the best of my ability so any help would be appreciated! This is really frustrating [:@]

 

Recheck the wiring, make sh\ure the Crank Position Sensor is working and connected, otherwise no spark. Is the MSD Opti for a 94 car, 96 and Optis are different mechancally than the earlier ones and won't work with the older engines without modifications

 

I will check but yes im sure it is for a 94 car. I checked msd to make sure it was. Is there a possibility the module is bad?

Where is the crank position sensor located?

 

Regarding the Crank Position Sensor. I think I had a case of brain freeze, the function of the crank position sensor is embedded into the Optispark, so there is not a physical CPS in the LT1. Sorry to make you search for no reason. There is a possibility that the new opti is bad, you could also look at the ignition module, and the ignition coil. Also check FUSE #11 in under hood fuse box.

 

Sorry its been so long but i now have an update. Ok so it now runs, i think the wiring was loose where it plugs in to the old harness beside the intake. It still isnt 100%, it now runs strong for about 10 minutes and then starts to cut out eventually dying. Then after it dies it wont start again until some time later like an hour or so.

I have replaced the opti as stated above plus the module and the coil is quite new.

Is there anything else that could be suspect?

 

Have you changed the fuel filter ?
Is the check engine lite ON ?

 

Yes ive changed the fuel filter. Could the fuel pump be suspect?

But i cant tell whether or not the CEL is on because either the bulb is blown or someone has blacked it out.

I took it to the local dealership and they said they suspected the O2 sensors but i recently replaced those too.

 

At this point it would be a good idea to attach a scanner to the car & look for active and retained codes, because it appears to go in trouble when in closed loop operation, which usually is an indicator of sensor trouble. The fuel pump could be bad, but I would think it would be bad right off the get-go, but it is a possibility.

Also, temporarily disconnect the wires to the MAF sensor, this will force the computer into open loop, and see how it runs when hot. If it runs good in this state, you have a sensor problem.

 

Ok thanks.

So about disconnecting the MAF sensor, should i do that before i start the car?
I disconnected it once while it was running and it shut it off.

 

You can do it before starting, as the PCM does not look at the MAF in open loop. The car should be able to run OK with the MAF disconnected, but will throw a code. If it does not, you may want to start looking at other sensors, starting with the MAP, O2, ECT, IAT.

But, really, you should get the car scanned.