I just recently rebuilt my 1997 lt1 camaro. It has less than 600 miles on it. Since the rebuild I have had bad gas mileage(13.5 mpg) and it has been missin. I also have had a bad vibration on the passenger side of the car as if it was coming from the transmission or exhaust. Well a couple weeks ago my car broke down. That day I had noticed that my car was hesitating and bogging down at a low rpm. Well I was at a light and when I was trying to take off, my car bogged down and died. It started right back up and started driving again. Later that day I was at another light and as soon as I was taking off it started bogging down real bad, started missfiring, and started popping real loud and within 15 seconds it died. I tried starting it again but it wouldnt start. Now everytime I try starting it, it has a real loud knocking type noise that even shakes the engine. I pulled the pan but the short block is fine. I assume that the opti is defiantly bad and possibly the ignition coil. I replaced the ignition coil and Im about to replace the opti within the next few days. Im most likely going to replace the spark plugs and wires. I took apart the opti and found out that inside the cap and rotor are both arching. Im really trying to figure out what could cause this knocking type noise. Im pretty sure the opti, plugs, and wires will take care of the bogging and missfiring, and that the oxygen sensors will take care of the bad gas mileage, but it didnt start this knocking noise untill the day that it died after bogging and missfiring. Well if anybody could help me out on any of these problems please do so. I appretiate any help given. Thanks alot

 

What did a scan show you?

 

I have tried two scanners on my car and niether of them have worked....they wont even power on

 

I forgot to mention that I just found that the ground wire from the harness to the block broke off.....

 

If you can't power up the scanner, check the fuse for the cigarette lighter.

 

I have already checked and all of them are good!!!
Today I bought a new optispark and tomorrow I will be replacing the old one, I also bought new spark plug wires and when I took one side off, one of them was completly broken in half so my car was only running of 7 cylinders

 

Well after replacing the opti, coal, wires, and icm I have no more knocking noise but now my fuel pump is bad so my car should be running when I replace it. Thanks guys