ALFAGTV6.COM

[Glen B]

Hello all,

could someone tell me how many volts to use to bench test a set of injectors on a spare fuel rail with pressure regulator and pump. The pump I assume would use 12 volts. The injectors all came with bosch conectors so that will be handy. Tried to get a voltage reading while the motor was running but the meter just freaks out.

Can I run them at a constant say 30 psi at a given voltage over half or one hour. Or should I make some sort of pulse system with maybe a turn signal flasher to a bosch relay that handles the lower voltage to the injectors? What size fuse should I use in line to the injectors? 1/2amp or more?
This way I could see the spray pattern and measure their flow to match them if they are even. Mix and match with the set that is on the GTV6 now

Can I get away with using Kerosine to do this test ? Gas fumes and I don't get along well.

Thanks for any help , Glen

[Mats]

30 psi sounds a little low, try 2.5 to 3 bar instead if you wanna check spray pattern.
12 volts will work great since this is what is used on the car. Normally the injectors are fed a constant 12v and grounded when they are supposed to open.

Opening the injectors fully for half an hour will surely overheat them and you will need a barrel to store the fuel coming out, try a minute maximum.

[Glen B]

Thanks Mats,

that's great. just thought they ran a lower voltage after that meter reading I got.

Sweet, then no extra parts save for plumming in a pressure guage and clamping the exit hose to 35-40 psi for the spray pattern test, a minute will do . Good.

[Mats]

You could always measure the voltage on the car by removing a connector from one of the injectors and measure on one of the pins to ground (chassis or battry minus) with the ignition on, if you don't get a reading try the other pin.

[Glen B]

Wouldn't the injectors be in the off mode unless the engine were running. Then when running....on/ off/ on/ off cycle per rpm? How would you measure an intermittent signal for true voltage?
Max rpm to the point where the injectors are open almost all the time?

[Mats]

As I said before, the injectors are fed a constant 12v current supply and the ECU grounds them when they are supposed to be open, i.e. closes the circuit.
There should be 12v on one of the pins when the ignition is on.

[Glen B]

You are right.
There is 12v (+) at the pins , ignition on , checked #2 and #5 connectors. Each pin on the same connector gave me 12v (+) with the meter, (-) ground to chassis. Zero volts between pins ,Check. Only measured between the pins last time.
Saw the bundle of black wires comming out of the harness to the right valve cover and thought they were the direct end of each injector lead to ground. Got my switch ends backwards.
So 12 volts it is, thanks