Need new ecm for 1991 formula firebird

Try loosening the bolt on the bottom of the distributor crank engine then turn the distributor a little it should advance or retard depending on direction you turn it you will be able to tell.

Fuel filter, fuel pump, Bad Gas !

See if you still have the Vehicle Emission Control Information label (the VECI label) under the hood on some radiator support member, probably. The spark plug gap is listed on it.

fuel pump is inside the fuel tank...you will need to drop the tank by removing the 2 straps that hold it up..make sure you put a jack under the tank so it does not fall and break the fuel lines when you get the straps off.
once you have the straps off , carefully lower the tank to provide access to the lines. Most likely you will need to aquire the fuel line removal tool...you can rent these fron Autozone..once the tank and lines are removed, you will need to get the fuel delivery module(FDM) out of the tank...there is a large "c" clip that holds the FDM in the tank...be careful when removing it cause usually the assembly is spring loaded and will pop up out once the clip is removed...now the bad news...the fuel delivery module may be very expensive for the whole thing...when at the parts store..see if you can just buy the pump assembly...the pump alone should be about 80-100 bucks...a delivery module may cost upwards of 300 or more...reassemble in reverse order...a word to the wise...when you take the tank straps off, there is the possibility that you may break the bolts...my experience with older cars is that you almost always break the bolts...so i just cut them off and replace with new ones

if ur key has a chip in it betweeen the chip and cylinder is probrably going bad a new think cause 30 bucks but lot time when cylinder wears out u have security problems

Use 14/16 guage multistrand automotive wire (red, black, green, blue) and crimped **** end connectors.

Change the coolant sensor, they are faily cheap and usually easy to get to. They are also prone to failure on the early years of fuel injection.

Find the point on the radiator support where the pins will be located.Be sure there isn't anything underneath to drill through.Measure from the fender to the center point of the hole location,and measure from the front fascia(edge where the front edge of the hood meets the body)to the center point of the hole location.Use these measurements to mark the hole on the hood.Repeat for the other side.MEASURE TWICE DRILL ONCE.

Have you done a vacuum leak test?Around the injector seals is a place to start Do you have a manifold vacuum gauge and if so what is the reading that your getting?another thing to check would be the idle bypass and pcv are clear/unblocked and operating correctly.Does this happen wether engine hot or cold?or both

Yes, it can be bypassed. Find the hot lead to the pump and connect a toggle switch from a power source.