I have pulse and fuel in a 85 base Camaro. Runs with starting fluid. Injectors work fine before the engine was swapped out to a 3.1 block. I think I may just have a weak pulse. What should the voltage be at the injectors to get them to fire properly? 12 volts?

 

Maybe I didn't ask the question right. Is there any way to tell if the current to the injectors is weak and still able to light up the tester when checking for pulse

 

iirc, there's 12v to them when key is on. The ecm pulses them with a ground signal.

 

So a bad ground connection could cause a weak pulse so the injectors would not open

 

I'm not basing this on any injector wiring I've tested but knowing 12vdc, yes. Turn the key on and make sure you have voltage in the 11-12 range before you go any farther.
If a noid light is used it should flash properly if you have the right positive and negative.

 

No.

The Fuel Injectors are NOT connected to a Chassis-Ground Connection (the way you are thinking anyway).

The Injectors are Pulsed/ Activated/ Sprayed by an Internal PCM Ground.
This is done to control when the different Injectors Pulse.

 

How much Fuel Pressure are you measuring?

 

I have not put the pressure gauge on the fuel line yet. New pump and was running fine, as far as injectors and pressure go. When I started to separate the fuel line for testing, it had a lot of pressure on the line. But to rule that out, I will move forward with a actual gauge. I may go ahead and install the injectors out of the 3.1 rail. I think they are supposed to be better injectors.

 

Not funny.! I have no pressure at all on the gauge. No sound in the tank from the pump. Every fuse I've looked at so far look good. Keep in mind that it ran before I switched engine. I pulled out the shop manual and will start ruling out what it is not. Just an observation I can see. No service engine light came on and I did install both oil pressure sender that mounts to the oil filter housing. They came out of the shed of spare parts. Any chance One of them would keep it from starting? I'm going to check fuel pump at the Aldl first

 

If you have no pressure showing on the gauge, then you're not ready to worry about "weak pulse" yet.

Concentrate on the fuel pressure FIRST. You may well find that any "weak pulse" issues will magically take care of themselves and disappear without a trace, once you have restored that and it becomes possible for fuel to be injected AT ALL. You could have the "strongest" injector pulse known in the civilized universe, and it still won't do A DAMN BIT BETTER than a "weak" one, if there's no fuel pressure.

 

I do understand that I have to get the pump running. I will be using the shop manual to trouble shoot. I'm guessing I have a bad ground or blown fuse. The fuel pump must have run a few seconds. Because there was some fuel pressure on the line when I disconnected for the test.

 

OK this thread is done. I have injector pulse and the fuel pump relay was bad. I have 50psi at the fuel line flex to hard line on the engine. Still won't run without starting fluid

 

You didn't disturb the ignition system in any way while troubleshooting any of this did you? Didn't unplug the coil, or "adjust" the "timing", or anything like that? Or even, just bump something?