scope103

Your concern is that the CSI is putting in too much fuel. Not that it isn't putting in enough. So you're worried that it is open all the time (not likely), or that it is leaking.

So you don't put 12v to it, you just pressurize the rail with no signal to the CSI (because you aren't turning the key to start). With no signal, no fuel should come out. That's all you're testing.

briholt

So that I understand, the steps would follow:

One, disconnect the CSI so that it is no longer connected to the Plenum.

Two, keep the csi connected to it's connecting wires

Three, jump the fuel pump wires so that I'm adding 12 V to the fuel pump, thus creating fuel pressure in the fuel system

Four, the csi should not have any fuel coming out

Five, at no point should I have the ignition on

Four, turn the ignition on

Five, the csi should not have any fuel coming out





Correct?

briholt

So, I jumped the Fp and B+ connectors and was able to hear the Fuel pump kick on with the ignition on.

I kept the CSI (cold start inject) connected to it's wires but removed it from the plenum.

When I turned the ignition on, and with FP and B+ jumped, I could hear the fuel pump but there was no fuel coming out of the CSI.

I went ahead and turned the ignition to start the truck and could see a strong flow of fuel coming out of the CSI, at which point I killed the ignition.

so that all seems to work.


But here is a pic of the CSI. and it's certainly fouled.




I suppose I should pull the plugs (I've done this before and they looked fine) but definitely pull the plenum to clean it.