i just did a rebuild on my 1994 z28..
THINGS DONE TO IT:
-block honed and hot tanked
- heads cleaned resurfaced and valves changed(factory specs)
- pistons checked and re-ringed(needed 2 new ones also factory)
-all new sensors
-pushrods checked(factory)
-crank turned and new bearings
-all new seals and gaskets(thats a must lol)
basically all new motor wise
THINGS BOUGHT AND UPGRADED
-CC503
-MSD cap and rotor
-MSD ignition coil
-rapid fire AC delco plugs
-bosch wires
-2500 stall torque convertor
-pacesetter long tube headers
-CAI
-.625 beehive springs
-1.6 self aligning roller rockers
-high torque starter


other then that every thing else is stock...ooo i took the emission stuff off such as the EGR system, and i was told to just take off that black vacuum purge box thing, not quite sure the name of it, but i have a friend who built a camaro and took it off and his ran fine unless hes messing with me. iv only got it started 3 times and all 3 times iv had to use starting ether and it runs rough...i know the computer needs to be tuned to the cam lift but its just doesn't start like it should and it floods easy..iv checked my spark(used one of my buddies as a ginnie pig and made him hold a screwdriver to the plug wires lol im such a good friend)and theres spark....so my question is, does anyone have any ideas on what i should do? i was thinkin i should put the factory starter back on and see what happens since its a smaller gear ratio but wasnt sure if that would work...so im up for any ideas...keep in mind this is my first engine rebuild and i did everything but the machine work myself...i went by the book on most things and asked friends and family for advice on stuff i didnt already know. PLEASE HELP!! I WANT TO GET IT ON THE ROAD IM A EXCITED 20 YR OLD LOL




--1994 z28 LT1--

 

Is your SES light on? What is your fuel pressure with the key in the on position? Fuel pressure when cranking? Are you 100% sure that you got the opti installed in the correct position? Is the coolant sensor in the water pump plugged into the wiring harness?

The black thing you are referring to....I'm going to assume that you did an air pump delete.....or an EGR delete. Was this black purge "thing" on the front or back of the engine?

The engine should run fairly smooth on the stock programming with the CC503(it does on my stock computer...I have two PCM's...one that is stock and another programmed for the CC503). Are you running the stock injectors?

 

There are at least 3 emissions systems that can be removed (with absolutely no benefit to performance) - EGR (valve and solenoid); - AIR (pump, lines, hoses and check valves); -EVAP (canister, purge solenoid on bracket passenger side of intake manifold). Which ones did you delete? When you deleted the systems, did you correctly block all connections, including the vacuum connections?

Next time, ask questions BEFORE you randomly start deleting systems you appear to know nothing about.

 

^^x10000 if u deleted egr and didnt block anything off thats not good!and deff no performance enhancement in doing so

 

ok for one im not stupid yes i blocked the EGR system off...now the EVAP system i took off was the black purge box on the driver side right below the ignition coil...and i did ask all these questions before any of these things were takin off before i did it...now heres my question??? i was told by a good friend of mine that has builts a couple LT1s and he said that the opti only goes on one way is that true? its not like i cant put any of these things back on i still have the parts...i have got it started but its being really picky on when it wants to...i havent checked my fuel pressure yet and was goin to do that today but ended up workin later then i thought...yes these r the stock injectors...all vacuum connections r plugged from the EVAP canister...yes my SES light is on...ill check my fuel pressure tomorrow and make sure that its at 100%

 

Sound like you might have the valves adjusted to tight..try backing them off 1/4 to 1/2 turn and try to start it.When you installed the opti spark,did you make sure to line the flat on the spline gear to flat on the cam sprocket?

 

yes i took extra time with that...is there a chance that it can be similiar to 180 out? iv never messed with the opti only drop downs...and ok ill try lossing my valves

 

We can start at the begining,when you did the timing chain,number one piston was up on a compression stroke?cam gear and crank gear dot to dot?When you did the opti,did it line up easily?Did you double,triple check the plug wires to make sure they were correct?Did you use lock-tite on the rotor screws?

 

"Black purge box" would appear to be the AIR pump. But then you already knew that. Did you block the connection on the air intake duct, between the filter and the MAF sensor?

You 94 has an "unvented" Opti. It is driven by a splined shaft that connects the Opti to the cam sprocket (forgive me if I'm telling you what you already know). In theory, the splined shaft has an odd tooth that only engages the teeth in the cam sprocket one way. Unfortunately, it is entirely possible to have it go together indexed incorrectly. I'd estimate, based on the past 11 years of reading/answering these posts, that at least 10% of the Optis go together indexed incorrectly.

Courtesy of Shoebox:

http://shbox.com/1/93-94_opti.jpg

Note that there is a similar arrangement on the splined shaft, where it pushes into the back of the Opti.

 

yes dot to dot on compression stroke...i did check the plug wires...im in the process right now of loosing my roller rockers 1/4 turn like u said....turns out i could turn about 6 of the nuts with my fingers so maybe this works but ill let everyone know and ill check the wires again and double-doulbe check

 

the MSD opti that i got came vented and it said on summit it was for the 1994 z28 camaros..i did research on it and chevy went to the vented opti in 94 and thats what was on it when i bought the car was a vented opti

 

You are 100% incorrect. MSD makes the vented cap for both the unvented and vented Optis. I have a 94. It came from the factory with an unvented Opti. Has a vented Opti now, and I can give you a detailed list of the required conversion parts, if you want it = cam, timing set, timing cover, short Opti harness, vaccum harness.

The only 94 that had a vented Opti, I believe was the LT1 used in the Caprice/SS/B-Bodys.

But then you already know that.

 

ya it wouldnt hurt to know...im always lookin forward to new things about stuff to progress in mechanics...

 

Sounds like its going to be a valve adjustment problem.

 

ya i started with that but got cold...iv never adjusted full roller rockers before so its something new to me