Ok.. I have this problem.. The shops dont know what it is.. Its been there for days. I have a 99 V6 camaro just pushing 80Kon it. I only run 94 octane in it, till one day it was just about 4.00 a gallon. So I down graded to 92, and an octane booster. Well now when it starts its rough. When you hit the gas from a standstill, it "falls on its face" and doesn't go anywhere. I had new plugs and wires put in about 8 months ago, and got an exhaust 3 months ago. When the RPMs get up to 3800, the engine sputters. and then it switches gears. Im losing a lot of unburn fuel also. Not cool... The engine fires a cylinder 3 missfire, when I can get it to throw the code. The one coil pack has been replaced, and the shop replaced the other 2, still the same thing. Then they started talking ignition module.. Still no dice. Now there talking gaskets, valves, and other engine work. The injectors, are fine. Fuel pressure is fine, and the plugs are fine. Cylinder 2 is starting to go bad along side 3. I am about out of ideas... Not a good problem. Any ideas?

THANKS FOR THE HELP!!!

 

Was the fuel pressure tested under load? Being that cylinder 2 and cylider 3 are on opposite banks, I don't think you have gasket trouble, but I still would do a compression test and see if there is a bad cylinder. The engine should run fine on regular gas, but the octane booster may have damaged some parts in the fuel system. Have the injectors been tested for leaks and fuel flow?
You may have some bad ignition wires even though they were recently replaced. Was ehr ignition module replaced ?

 

I believe the fuel was tested under load, but I dont know. I didnt think it was a gasket, but thats what they said. Ill see if I can get a compression test done. If there is a bad Cylinder, that has a hefty cost associated to it dont it? Ill just go drop a LS1 in it . So those octane boosters are bad for the engine? I did add a fuel ingector cleaner a few times to try and clean the ingectors. The shop told me my injectors were fine. The ignition module was replaced, but they said that did not cure the problem. So they put my original one back in there.