Hey guys I’m getting pretty stumped on what my engines doing.. so last year I drove my 91 camaro rs 305 tbi to work just fine and at the end of the day I went to start it up and it did but then just died. I started it up again and it was acting like it was dying for fuel and was really sluggish and not wanting to go. So I decided to replace the pump and filter.. that did nothing. So I got ballsy and pulled the engine and went through everything with a new intake and cam and headers. I’ve replaced every sensor and sending unit even the ecu. Still I can get it idling but once I start giving it throttle it will bog way down and not pick back up till I let off and it’ll sound like it’s missing. I can’t think of anything else I can do beside possibly giving it a carb. And! The only code I get is no pulse at the ecm. But I heard with the car not running there would be no pulses..Code 12. And my check engine lights always on.

 

WHAT is the fuel pressure at the throttle body?

WHAT is the cranking compression of all eight cylinders?

WHAT is the back pressure ahead of the catalyst?

CONNECT a scan tool, look at the data stream. Codes can be helpful, but the data stream tells all. I'd especially want to know what the engine coolant temperature is, what the MAP sensor is telling the computer, the O2 sensor data and cross-counts, the short- and long-term fuel trim, and the knock sensor activity.

HOW old are the usual tune-up items? Spark plugs, plug wires, distributor cap and rotor, air filter? Have you tested the ignition coil with an HEI-calibrated spark tester?

Is the battery under-charged? Corroded battery cables? Corroded fuseblock?