My car has been running rich-- So I pulled up the fuel rail to check for leaking injectors.
I used a fuel pressure gauge on the rails when everything was hooked up and the pressure shot to 40 psi and completely dropped back down.

I turned the key with the fuel rail pulled but none of the injectors dripped meaning that the injectors arent leaking.


Still doesnt make sense why the pressure completely dropped with the Fuel pressure gauge.
Could hooking up the wrong injector wire connector to the wrong injector cause it to run rich??? and is there a way to tell which exact wire should go to which injector???

I am planning on checking the fuel pressure reg in a bit.

 

You can't hook the injectors up wrong, so you're okay there. Loss of pressure combined with running rich, would have me looking at the FPR (since the injectors are not leaking), the diaphram may have a hole/rip/tear in it allowing extra fuel into the intake and bleeding the pressure off. You'd probably be able to pull the vacumm line to the FPR and smell fuel in it.

 

Ok, on a TPI motor it has what they call batch fire, meaning the injectors on each side of the motor all fire at the same time, regardless of where the piston is in any of the 4 strokes. So as long as you have them all hooked up on the same side that you had them on, individual injector plugs will not make a difference.

In terms of the fuel gauge, first I would check the FPR, it is easiest to check. With the car running and the gauge hooked up, pull off the vacuum line to the FPR and see what happens. The fuel pressure should shoot up about 7psi from the previous reading. If when you pull the regulator vacuum hose, gas starts leaking out, you have a bad regulator. If not, you have a bad residual check valve in the fuel pump itself, and the fuel pump will have to be changed. Also, check and make sure your fuel filter is not plugged. Always change the fuel filter whenever you do a fuel pump, or any other fuel system repair.

 

The esiest way to check for a bad injector is to check the resistance of the injector. Just get your ohm meter fired up and put the red lead on one of the injector's prongs and the black lead on the other prong. You should get a reading of 13.5-17on all of the injectors. As long as the readings are all showing a constant reading. If one injector is off of the rest of them, you probably have a bad injector.

 

I replaced the FpR

The manual said to Torque it to 15 in
But I didnt have a torqu wrench so I just tightened it firmly tight

Will this cause the FpR to fail?

 

I doubt that you could damage teh diaphragm by over-torquing the screws. It is more likely that the threads in the FPR base would strip before that occurred. Another thing to bear in mind is that the gasket/diaphragm position must be maintained while the screws are being tightened. That can be a little tricky while holding the cover against the spring and starting the screws.

Your leak down may not even be due to the FPR, but could be a result of check valve leakage at the fuel pump. That is not a serious problem so long as the pump can maintain adequate pressure while the engine is operating.

 

That test only checks the coil of the fuel injector and not the mechanical side (pintle and seat) of the injector. The proper way to check a fuel injector is with a pulse tester. THat will check the electrical side of the injector and the mechanical side. What you will do is hook up the pulse tester to the injector and a fuel pressure gauge to the fuel rail. Key it up so it develops fuel pressure. Then push the button on the tester. It will pulse the injector for a certain amount of time and you will monitor the fuel pressure drop. If it does not drop, that means it is not working. If it drops, you then have to test the rest of them and compare how much they all drop. They should all be within a few psi of each other.