Stay with the stock injectors. Have them cleaned and flow matched and you will be very pleased. Injector size is determined by HP generated at the crankshaft and the number of cylinders of the engine. The Fiero 6 cylinder generating 140 crank hp with a stock fuel pressure of 43.5 psi requires 15# injectors. The 17# injectors will not improve performance, will decrease fuel economy, and will likely cause a rich burn condition. The stock Fiero ECM generally doesn't like aftermarket injectors if they aren't pintle style and will often cause a rich burn condition.
Look at this injector size calculator. Plug in 140 hp and 6 cylinders to see what you get. Flow ratings are rounded up to the next even pound.http://www.fuelinjectorconn...size_calculator.html
[This message has been edited by fierofool (edited 06-04-2014).]