I just did a tune up on my 1991 firebird 305 tbi. I did intake manifold gaskets, plugs, wires, front seal and timing cover gasket. Before I did all this the car would move out ok for a second or so and then fall on it's face and barely pull at all. The higher the gear the lower the rpm this would start.

I did a tune up and thought this would take care of it. The car idles a lot better and drives smooth under normal conditions, but under wot it still falls on it's face rather quickly and makes no power. I set my timing at 2 degrees, gapped plugs to .035" and properly sealed everything. Also there are no vaccum leaks that I could find. I need help!

 

Have you checked your fuel pressure when the car is under load?

 

Did you replace the fuel filter and O2 sensor? Did you set the timing with the EST dissconnected? Did you make sure you put all the plugs wires on in the correct location (lord knows how many times I have screwed that up).

 

Thanks for the response. The fuel filter was indeed the problem. I didn't want to mess with that at first because the fittings were so rusted on there, but I narrowed it down to that and cut the line and replaced that section with a new line and fuel filter. Car runs good now.

 

Good to hear!