I need help trouble shooting. I have a 1990 Iroc that I'm swapping a 2000 LS1/T56 Combo - stock. I bought the wire harness from Pocket and the kit that Hawk's Thirdgen sells. The kit comes with the mounts, throttle cable, a/c condenser cut out plate, trick flow fuel pressure regulator (w/pressure gauge), and fuel pump/harness. I'm using the stock gas tank for now. I installed the high pressure fuel pump with the elec harness that comes with it, the fuel pressure regulator without a problem. The harness comes with a relay that has a "quick disconnect".

I attempted to turn it on, and it turned over but did not turn on. I sprayed some starter fluid into the throttle body and it turned on. If I keep spraying fluid into the throttle body, it stays on. I checked the fuel pressure, 0. I then checked the power to fuel pump and found a power problem.

I have power from the red wire coming from the alternator and there is power back to the relay. However, after the relay I checked power at the disconnect and nothing. I check the ground and no problem there. I disconnected and connected the ground just to make sure.

I disconnected the after market power harness and connected the plug back to stock and nothing. When I test power going from the car to the gas tank, the test light is very dim.

I'm looking for ideas as to how to trouble shoot.

Any ideas would be appreciated.

Thank you

 

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What does this connector go to? It's directly under the dash.

 

I connected a scanner and it came back with some codes. P0449 - Evaporator Emission System Vent Control Circuit Intermittent, P0452 - Evaporative Emission System Pressure Sensor/switch Low Input, P0803 - 1-4 Upshift (skip shift) Solenoid Circuit, P0405 - Exhaust Gas Recirculation Sensor A Circuit Low, P0102 - Mass or Volume Air Flow Circuit Low Input, P0443 - Evaporative Emission System Purge Control Valve Circuit.

I haven't connected the maf and emissions equipment. I had the vats deleted on the CPU but have not had them delete emissions for now. I just want to get it turned on and later connect all of the emissions.

 

I have the same issue, and have had it for a bit. I went around it (because I needed the car driving) and wired a wire directly from battery to a switch back to the stock connector for now.

My power issue originates from the relay the PCM sends a signal to, not the harness from racetronix or the stock wiring.. I'm going to track down the issue eventually and fix it as I don't want to keep having to turn the pump on manually.

 

Does your fuel pump power wire run from the relay to the C100 connector? I ran my painless wiring fuel pump hot from the relay to the fuel pump power wire on the C100, which I think was a tan wire. Can't remember exactly what color it was, I'll have to look at my schematic when I get home from work. But it turns my fuel pump on with the ignition.

If so it should send power to the fuel pump. You should be able to test the plug at the fuel pump harness for 12v.

 

Based on your description is sounds like the relay control circuit isn't working. Make sure terminal R9 of the LS1 PCM is physically connected to the field control terminal of your fuel pump relay (however you chose to route it).

 

I need to do some more reading to understand c100, fuel pump wire to the pcm because I'm not familiar with that. I bought the harness from a member here and connected it.

I did get some direction and wired the fuel pump direct at the relay in the engine bay. Doing that gave me power but the pump did not work. I'm going to try a few other things before I drop the tank. I have two problems, one I'm not getting power to the fuel pump wires without jumping the wires and the other my fuel pump is not turning on.

 

Just to update, I found the problem. The small original harness that connects to the fuel pump inside the gas tank was a little rusty. I used sand paper to clean it and it works. Thank you guys for the replies. Thank you Pocket.