I just put together a newer engine, I recently aquired an lo3 from an 89 iroc with only 80k on it and it didnt have any cylinder ridges, and still had cross hatch although it did sit with some water in the cylinders for a little while, but only had minor surface rust. well, I didn't take apart the bottom end at all because everything looked so good. and I put a freshly rebuilt and ported set of 416's port matched to a performer intake, a comp cam xe256, new timing chain, excell super coil, accel pro stock wires, high volume oil pump, summit headers, ac delco rapid fire plugs, and a rebuilt non cc quadrajet. i went to start it the other day and it only ran realy really rough on 5 cylinders! i don't know what the problem could be, then it wouldn't run at all the next day. can some one give me some idea's? i adjusted the valves twice to make sure it wasn't the issue.

 

timing, firing order, valve adjustment

 

Did you set up the Rochester for a 305 before installing / starting it? Chances are that it needs the final adjustments, float level and drop check, A/V adjustment, primary idle mix adjustment, etc.

If your plugs are wet with fuel, you'll get nothing.

 

yes the rochester was rebuilt with my specific setup in mind, no i haven't made the final adjustments on the idle because I can't get it to run long enough.


timing is hard to set while it's not running, but firing order and valve adjustment are on, i double checked them both.

i'll try to mess with the idle speed and air valve adjustment and timing some more, hopefully I can get it to do something.