I have just finished up my 383 buildup But now I am haveing problems. My car when I start it does not want to stay running stumbles cuts up& dies and has very little throtle response. I have pulled the coil wire and I do have a msd 6al ingnition Anyway with the coil wire off I turn the engine over and there is a lot of spark there so I hook it back up to the opti and pull a wire off one off the plugs and turn the engine over hardly any spark so I pull another plug wire same thing. So I disconnect the msd and just run the factory ignition and I can not see any spark at all. I am a little confused I have a brand new GM opti. It has done this scince the engine was first fired up. I did not force the opti on I did up grade to the vented opti with a tru double roller timing chain electric water pump. I have every thing installed on the new opti vac harness and the wiring harness. My car is not showing any misfire codes. Vacuum is 13in at 1100rpms the cam I have is a cammotion 237/245 on a 112lsa 17.7 deg of overlap I have a 12.1 comp ratio I do have 100ll gas in it right now and I am geting up to 8deg kr. Is this possably a bad opti? The car also sais its runing lean but actualy its not it is running very rich. I can not under stand that either. Is 13in of vac at 1100rpm good with the cam that I have or do I possiable have a vacuum leak? Keep in mind that even though the car is at 1100rpm it is a crapy idel. This is about to drive my nuts trying to figure out what is wrong I have also sprayed starting fluid over every think that could posiable be a vac leak and and have not found anything out of the ordinary. Any help would be GREATLY APPRECIATED.THANKS

 

Sounds like a weak coil under load...

 

I have already tried putting the stockcoil back on same results. The stock coil was good when i replaced it with a msd coil. Thanks for the advice.
Anymore suggestions?

 

I think you need a tuneup.

 

Everything is brand new. new engine ,plugs wires, opti, 02sensors opti elec harness, opti vac lines I have replaced the plugs twice the coil once with a used one that was working when removed. I have ordered a new opti to replace the new one I have now. I that does not fix it Not sure what I else to do.

Would it be strange if I have 17in of vac at 1800rpms and 13in at 1100rpm?

 

Make sure your air system is sealed between your throttle body and your MAF sensor. You might have you upgrade your OBDII system.

 

It is sealed I have checked numorus times. Also I have checked for vacuum leaks numorous times. I have not found any. I have a obdI do you mean I may need to upgrade to an obdII system? As far as doing the vented opti swap conversion. Do I have to program the computer for the vented opti since my car came equiped with a non-vented opti?

 

You might just need to program your computer for it, after you get that and it is still messed up and showing Knock, then you should be worried.
After my rebuild, we tried to run the car without the newly burnt chip and raw fuel was coming out of the tailpipes.

 

I am almost positve that the new opti is bad due to the low spark. But would like to know all the posiable problems that might cause this problem. Hopfully I will get the new opti thursday. I hope the new opti fixes it. Or I get an idea that I have not tried and try it and it fixes it.

 

There is absolutely no programming for the opti. Based on what you have said, I would suspect something wrong with the rotor in the opti. Hopefully your new one will take care of it.

 

I sure hope that is the problem. I cant wait to drive it down the road.