I am using the signal for the fuel pump, through the PCM, to run my electric waterpump. Well it only signals the wire to stay hot for a few seconds. About the same time the fuel pump runs then shuts off. I thought its suspose to stay hot while the key is in the ON position. Any help? Thanks. -Matt

 

You should be running a separate relay wired up to a "key on" source to power the water pump. Not smart to combine it with the fuel pump.

 

I am running a seperate relay but that doesn't change the signal the computer is giving out. I tapped into the fuel pump wire through the PCM for the signal.

 

You need a separate "key on" source to power your relay. Don't tap in to the fuel pump circuit.

I'm not sure of a good point on a Camaro. On the Vettes they have a convenient, unused "key on" 10 amp wire hidden in the center console.

Hopefully someone will point out a good place to tap off a signal. I'd avoid the PCM wiring (just my opinion) since it seems to be very sensitive to voltage. You may get odd things happening if you do.

 

Seems to be what most people are doing when running their electric waterpumps on here. Just thought when the key was on the ON position the pump was running constantly, not for a few seconds then shutting off. Im wondering if when the car is started if it signals the 12v's and doesn't stop. I need someone to chime in who is using their fuel pump signal for their electric waterpump. -Matt

 

I am doing that. I use the fuel pump signal wire to pull a relay in to power the waterpump. What you are seeing is the fuel pump priming. Once you start the car (oil pressure over 5psi) the fuel pump runs. I think this way is better because when you put your car in accessory the waterpump won't kill the battery.

 

I used the coil 12V supply as my electric waterpump relay signal.

 

Thanks guys thats all I needed to know. I didn't know the signal from the PCM did this for the fuel pump. I was under the impression there was 12v all the time when the key was in the ON position. This clears things up for me. Yeah it is probably a little better like this so I can leave the car on without my battery dieing. Thanks for the replys. -Matt

 

The PCM shuts the fuel pump off when the engine doesn't start.... there is no pulse signal from the Opti low res sensor, and when that signal isn't present the PCM shuts off the fuel pump and the injectors. There is NO interlock to the oil pressure on an F-Body LT1.... the oil pressure sensor does not connect to the PCM.