My car has been running REALLLLLY rough ever since i put this new motor in. I can't for the life of me figure it out. It is a stock motor with a lt4 hot cam in a 93 z28. I had the thing tuned to no avail, the computer reads the right bank as going really rich then it leans it out so bad that the whole car starts shaking and it cuts out til about 2200 rpm. I have replaced o2 sensors, changed spark plug wires, re-adjusted the valves, put new ford racing injectors in, put the stock chip back in, all of this to no avail. The engine is also leaking oil from what I can tell at the water pump drive, could this have fubared the opti? ANY help would be GREATLY appreciated, as this is dang near un drivable.. The problem seems to get a LOOOOT worse when the engine warms up or I have been idling for a while. When I first start it it runs great. Also if I shut it off to get gas and get back in it, the engine surges HARD under a load IE when I take off from a dead stop but then clears up at above the 2200 rpm mark.... Again, Thank you very much!

 

Are you getting good fuel pressure?

 

Yea I am getting 40 psi at idle and it stays pretty much above 35 all the time no matter what I do. It is dark out here so I went and ran the car in pitch black conditions so I could check the plug wires for arching, every once in a while i could catch a small arc from the coil wire and the left bank. It was maybe 40 seconds or so in between each arc

 

anyone?

 

Check the opti for sure, make sure its not messed up and sending bad spark. I have a similar problem but im not sure how to handle it because my opti is good. Once u have confirmed the opti is good, check everything else in the motor ignition wise. After that check the fuel system. Ive had so many bad optis before. I cant stand those things.