Hey Guys, Longtime reader, new poster. Have a 95 z28 Camaro with a freshly rebuilt Lt1 engine. I've gotten the engine in but when started it runs very rough and the car dies. It runs as if the car maybe miswired. The wiring has been checked and replaced as well as the plugs. Fuel pressure is fine, o2 sensors are fine and i'm at a lost as to what else coud possible be the cause. Oh and the car has a 54760 Lunati cam. I was told by engine builder and Lunati that this cam does not require a computer tune for car to run. Anyone use this cam in their build? Any help would be appreciated. Thanks

 

Do you have the rockers adjusted properly? Did you reuse the old opti and other parts? Is everything hooked back up completely?

 

Rockers were checked today and they are adjusted properly. Old opti is on the car and today i also noticed there is one purple plug that is not connected. I was unable to find anywhere to connect the plug. It runs along the driver side near the brake lines. I have a picture but having difficulty finding a way to upload the image. Thanks for your assistance.

 

The stock cam benefits from reprogramming, when someone told you an aftermarket cam was fine with stock programming you should have walked away. That cam will run on stock programming but wont run right. I might even expect it to need a little throttle to stay running on a cold start.

I really don't think you will find anyone else having used that cam because the lift is WAY too low for a reasonably planned build.
For the rest of you it is 213/219 .447/.471 112lsa

When you say it starts and runs rough will it smooth out with a little throttle?
You did not change injectors did you? Sometimes people put in bigger injectors and try to use stock programming and that will damage an engine FAST.

 

Thanks for input 96capricemgr. The injectors have not been changed, and it does not smooth out with throttle. It actually seems to get worse with throttle and cause the car to shake. I'm also currently trying to determine all mods to car so that i can possible have it retuned.

 

I purchased the car as an unfinished project from someone else and just trying to get it going.

 

I would carefully recheck the plug wires, the opti has them numbered. I know it is basic but it is easily messed up.

I get a pack of multicolor zip ties and mark both ends of each wire that way just to be sure they don't get mixed up.

 

Ok, I will try that tomorrow and possibly a new opti if local parts store stocks one

 

If you end up replacing the opti, I recommend getting an Ac Delco oem one. The aftermarket ones are more trouble than there worth. JMO

 

I agree with the opti replacement but before shelling out a pay check for a new oem one, I would definitely check out the wires first. Been there, done that. Had "custom fit, crimp yourself". Apparantly I wasn't too good at crimping... Still amazed today how a V5 can still kick azz on the turnpike.

Created an extender with old spark plug, solder wire to end, put a rubber boot on it to insulate the connection, and then ran the wire so that I could easily just pull a spark plug wire off the block, plug the modded spark plug in it and then checked for voltage more conveniently at the top of the block. Identified the "dead" wires, and then went underneath to the opti and corrected the crimping issue. For you, you could still do this, figure out which one is not firing and then swap another known good wire in and check again. If you get voltage... bad wire/connection, if the problem still remains, then it's the opti. Just hate to see spending the big bucks until you are absolutely sure that it is the opti.

 

Checked wires again and they are correct. New opti should arrive later this evening. Will get back with results. Hopefully this does it.

 

Be sure to get the opti installed properly, i.e. the dowel lined up right. It is possible to put it together with the cam dowel in one of the bolt spaces and it appearing to be right. Obviously it won't run like that. Reading your original post, that would be my guess.

 

New optispark on car and it now runs correctly. New oil pressure issue has come up and i believe that's going to be a simple issue seing as a manual gauge shows pressure correctly. Thanks guys for all your help, it has been appreciated.

 

Always nice to kinda guess and turn out that was it. Thanks for the update! Did you end up going oem or aftermarket?

 

After reading all the post about aftermarket, i felt like the only way to go was OEM.