My 73 2.0l is misfiring under load. The original 3 prong fuel pump went bad and I replaced it with a 1 in 1 out fuel pump. Couldnt find a diagram that showed how it should have been hooked up so I dis-guarded the Y that took the R on the pump and hooked it up directly to the supply line to the engine compartment. After that the car would not start by itself fuel pressure it running around 28lbs. If you spray starting fluid into the intake then it starts and idels fine with about 26-27PSI. However when you push the accelerator the car begins back firing and running poorly. I changed the points in the distributor and made sure it had the correct spacing, I believe it was .016. It ran better, but still poorly. I have been working on it for over a month and I am at a loss. Can anyone offer any insight?

Hello, yes late type fuel pump is removing the Y connection on the return line.
Try to increase the fuel pressure to 30psi and maybe it will help. 27 or 28 is in the lower pressure.

A bad ignition condenser will cause a misfire under load. I see you changed the points but did you also change the condenser?

I did not change the condenser, after I changed the points I got it running and the condenser was hot at this point. I will change that and let you know if it worked thank you guys!