My 1989 Firebird Formula 350 Just started to run rough and started missing all of a sudden, the exhaust smells like bad gas or unburnt gas. I have replaced the O2 sensor, ignition coil, the pickup coil, Distributer cap and rotor button, Checked all of the Vacume lines, Replaced the Fuel pump, Put new 7mm plug wires on the car and new plugs I also replaced the ECM, But the car still runs very rough and has a big power loss If anyone could please help me The motor has only 7,000 miles on it. Freshly rebuilt. this TPI engine has thrown me for a loop could use the help.

 

i am having the same trouble as you but with an 83 carbed 305. out of the blue it started running rough, have you checked timing on the car? i have changed wires, rotor, carb was retuned and i tried to adjust the timing some, nothing has helped so far

 

What injectrs are you running? stockers? if so ohm check them. Also check the fuel psi regulatr vac line for raw fuel. if you have some in there the reg diafram is bad.