Ok I' lost I seem to be dropping 4 to 5 cylinders at low speeds with very little throtlle petal. Like when I am in a parking lot or pulling out of my lane. It has not set any codes and runs like a champ on the road. You can feel it a little in OD. I have replaced the plugs (ouch), wires, cap and rotor. I disconnected the plug on the trans. I had the local garage motorvac the whole fuel system with all new filters. Replaced the TBI and adjusted the fuel pressure up. Anybody had this happen before?????? Please help.




91 Carmaro RS
305 w/ 700R4 Ported TBI, 14 psi fuel pressure, open element, flowmaster cat back, 8mm wires, 180 deg t-stat

 

what do you mean??? Running rough? Dropping 'four to five cyls.' is a real bone jarring experience. I take it you mean it runs rough at low rpms and loads. It could be a number of things, like a weak ignition (ulikely since it runs well otherwise) or leaking valves. Hook a vacuum gauge up to the engine and post teh results. Run the engine at idle and observe the needle. There are more things you can do but this will be good for a start. The vacuum gauge wont tell wont tell everything, but it can tell alot for what it is.