Let me begin by saying that I have limited experience with electrical issues. I will do my best to explain what I have completed and checked. If I am unclear with anything, I can try to re-phrase it. The symptoms are that I am not getting fuel through my newly connected fuel injection.

I have completed all of the installation of my Holly Projection (2D version. I checked all of my wiring and everything "appears" to be ok. I used a multimeter to check voltage thru my wiring at various points. I am getting power to the fuel pump and to the ECU. The relay is working correctly. The various sensors are working (low voltage coming from the sensors-- I could be wrong)

I am also getting a low voltage reading out of the green wire going to the fuel pump. It seems to diminish as I get closer to the fuel pump. Also, I do not get any voltage reading on the green wire going into the ECU. I would assume that the signal/voltage would go from the ECU to the fuel pump. Is that correct?

What else can I check? My last remaining hope is that the "green" wire going to the fuel pump is not carrying the correct voltage to the fuel pump to operate it. I doubt that is the case as I connected a spare (new) fuel pump within the engine compartment. It still did not function (make a sound)

My big concern is that the ECU is bad. How do I test it?


Any help will be hugely appreciated. I'm heading to Moab in two weeks!!

Double check ALL your grounds.

When you turn on the ECU, the fuel pump should run for 2-5 seconds to pressurize the system to 15 psi.

Check your ground at the fuel pump. There is a power wire (red, green or green black) at the pump, and a black wire. The black is your ground.

If your pump isn't grounded it won't run. Get a circuit tester and check the power off the green wire going to your fuel pump.

For the fuel pump relay, you should have b+ power to 30, your ign switch should connect to 86, and ECU power will come off 87. 85 should go to ground.

Check all those things with your circuit tester. If you don't get power off 87, then change your relay.

Tim.

The relay is working correctly. All the grounds that I have are also grounded well. I have double and triple checked that.

The fuel pump is not grounded. There is no place to put a ground. It only has two wires connected to it. A red power wire and the green one that I was assuming was a signal wire of some sort. That part of the harness is grounded up in the engine compartment. But I don't know if that matters.

I do know that I have an older version of the Projection. The instructions that I printed off of the holly site were too new. I had to get an older version from someone. I don't know if that is why there is no ground to the fuel pump???

How would I ground it?

you don't need to ground the fuel pump, just plug it in as it is. I would suspect the ECU is the prob. It is not telling the pump to turn on, from the sound of it. You may want to try cutting the red wire to the pump, and touching it directly to the + battery terminal, the pump should then kick on, and you will know that the pump is good. Then, you will have to re-splice the wire, but i think you're prob is the ECU. Did you buy it used?

call holley and see if they will exchange it...

Originally posted by J Kimmel
The relay is working correctly. All the grounds that I have are also grounded well. I have double and triple checked that.

The fuel pump is not grounded. There is no place to put a ground. It only has two wires connected to it. A red power wire and the green one that I was assuming was a signal wire of some sort. That part of the harness is grounded up in the engine compartment. But I don't know if that matters.

I do know that I have an older version of the Projection. The instructions that I printed off of the holly site were too new. I had to get an older version from someone. I don't know if that is why there is no ground to the fuel pump???

How would I ground it?

YOU NEED TO GROUND YOUR PUMP.

The red is power at the pump takes power from the ECU). The power wire from the ECU relay should be green/black. When the ECU powers the pump, it put's power to this wire.

The other wire is your GROUND and it should be GREEN at the pump. And yes, you need to ground it.

I did buy it used. I will call holly on monday and see what they say about it. (I may be screwed???)

I will check the ground again. Maybe find away to ground the pump specifically. not just in the engine compartment.

Thanks for the ideas.

I don't know how more specific to be. You need to GROUND your green wire at the fuel pump.

This is taken DIRECTLY the Holley manual

Locate the single GREEN/BLACK wire at the fuel pump relay. Feed this wire down through the engine compartment to the underside of the vehicle. Route the GREEN/BLACK wire to the fuel pump. Connect the fuel pump pigtail connector to the fuel pump. Crimp an insulated female spade terminal on the GREEN/BLACK wire and securely fasten to the RED wire (+) of the fuel pump pigtail connector.

Crimp an insulated male spade terminal on a length of BLACK or GREEN wire and securely fasten it to the GREEN wire of the fuel pump pigtail connector. Fasten the remaining end to a suitable ground connection under the vehicle using the appropriate ring terminals. Improper ground connection will result in the failure of the fuel pump to function properly, creating driveability problems. Securely fasten all wires with the supplied cable ties along the frame rails of the vehicle

I understand what you are saying about grounding the pump. My confusion lies in the fact that there is no connections other than the harness plug, nothing at all for a ground, nothing.
I would think if it was necessary to ground the pump at the pump there would be some sort of connection or place to connect a ground wire, understand? There are no connnections on the pump other than one plug and a fuel in nd a fuel out.

It only has two wires connected to it. A red power wire and the green one that I was assuming was a signal wire of some sort.


Ok, you said in your earlier post that you have TWO wires coming off the pump right? A red one, which is the POWER wire, and a GREEN one which you assumed was a signal wire. It's not. It's a GROUND WIRE.

Red=power
green=GROUND

The red goes to the green/black wire that connects to the relay from the ECU, the green wire goes to GROUND.

This doesn't seem hard unless I am missing something.

Tim.

Originally posted by WOLF359



Ok, you said in your earlier post that you have TWO wires coming off the pump right? A red one, which is the POWER wire, and a GREEN one which you assumed was a signal wire. It's not. It's a GROUND WIRE.

Red=power
green=GROUND

The red goes to the green/black wire that connects to the relay from the ECU, the green wire goes to GROUND.

This doesn't seem hard unless I am missing something.

Tim.

He is correct on this..... Hook your friggen green wire to the chassey. :rolleyes: It's real easy put a solderless hoop on the green one. Attach it to the bolt that holds your pump to the frame. YES I HAVE ONE! as well as clubmembers and customers of mine! If your having trouble with this part I am real curious if your going to be able to dial it in........ I'll be watching the for sale section for it!