I'm relatively new here, figured it was time to get some help.
Me and my stepdad have been working on an 87 TA for about the past month and a half now, and it's really starting to **** us off.
We took the 305 TPI out of an 85 TA, switched around the wiring harness and everything.
But for some reason, we kept getting only 10 pounds of fuel pressure.
So we changed the fuel pump, twice actually, and that didn't work.
Put in a new fuel filter, still nothing.
We even completely took out the fuel rails, blew them out, and then replaced the fuel regulator.
Just tried it this morning, and still 10 pounds.
We're supposed to be getting anywhere from 41 to 47 pounds, so we can't figure out why we're not, however, neither of us know much about TPI, so that might be a contributing factor.
ANYWAY.
Help us?

 

Does the car run? Is it at all possible you are getting more than 10 but the gauge is reading wrong? Just a thought.

Other than that there are different fuel pumps. I ran into a situation on a chevy truck where someone had put the wrong pump in and the pressure was low. I think it was a TBI pump, I don't remember exactly, but the pumps were both electric and looked the same but the wrong one wasn't building enough pressure.

If you have the right pump do a voltage drop across the pump. If you back probe the connector at the tank, one lead of a volt meter on the pos wire and one on the neg wire there should be close to battery voltage, if not then there is resistance somewhere in the circuit

That's all I can think of at the moment

 

i agree with checking the voltage cuase u could have a bad ground

 

Yeah, it could also be somewhere in the positive side as well, maybe too much resistance in the relay or a connector for example.

To the OP if you aren't familiar with voltage drops I'll try to explain a little. Say you measure the voltage between a device and the negative battery post. You are actually measuring the voltage drop from the load of the device. The loads in a circuit will consume all the voltage supplied. Say you check voltage from the pos battery terminal to the voltage side of the connector on the part. There should be little to no voltage on the meter. Whatever is on the meter is the voltage drop in that part of the circuit. There is usually a little due to switches and connectors. More than 1/2 a volt is too much, same with the ground side.

What I'm getting at is if there isn't a 12 volt drop across the pump itself (pump running) then check from the pos battery post to the voltage side of the pump, and then the ground side of the pump to the neg battery post to find which side of the circuit you are losing voltage.

 

Haha, we figured it out, we took the pump back out, turns out there was a hole in one of the lines on the pump, straight out of the box.

 

Glad you found it and it was an easy fix. I hate it when bad new parts cause me to waste time.