Question: Injector problem?

[English Guy]

Can any of you folks tell me if i should be getting a voltage reading from the plugs that power the injectors when the the ignition is on but not cranking engine, or are the injectors given power only when the engine is actually being cranked?Many thanks in advance

 

[surfer93]

OHM the injectors when car is warm, If they are below 13, then they are bad.

Injectors get a pulse when the ECM tells them to fire, no power till then.

 

[1963SS]

Injectors get a pulse when the ECM tells them to fire, no power till then.

I don't know about Corvettes but most GM injectors have power to them when key is in run/start or crank mode. The ECM grounds the side of the injector that does not have power. So if it's like most GM's that I have seen Yes, there will be power there all the time if the key is in the right postiion. So, turn your key on and check for power should be right. Maybe.
Maybe one of our Guru's will step in and correct me if'n I'm wrong. Good luck.

 

[toptechx6]

Reply #3 is correct, the injectors should have 12 volts with the key on, the ECM pulses the injectors by switching the ground. There should be two injector fuses, one for each bank.
Also ohm test your injectors as surfer suggested, on an L98 if one is shorted (low resistance) the ECM will not fire any of them.

 

[boomdriver]

yes, all engine control systems are "controlled grounds", meaning that the hot side of the circuit is always on and the ground path is either opened or closed to manage the circuit. That is because grounds are safer and ECM friendly.
If I remember correctly, your injection system should have all 4 on one side fire together, not indivually. Single signals came with the LT motors I think....and OBD-II ECM's with more available computing power. So, when one injector opens, they all open on that side. This allows a fuel charge to be in the port as the intake valve opens. Later engines fine tuned fuel injection with injector control that allowed injectors to fire only to cylinders that were going to intake stroke.

 

[TedC]

Boomdriver, you are correct. The L98 injectors are bank fired. Right and left side, 4 at a time. The ECM processor used was not fast enough to process individual injectors.

 

[English Guy]

Thanks for the info Boomdriver very helpful,have a good one.

 

[English Guy]

Thanks for the reply 1963ss, appreciated.

 

[English Guy]

Thanks for the input Ted C.

 

[English Guy]

Thanks for the reply Toptech,i ohm tested all intectors and they are all A-ok luckily for me.

 

[English Guy]

thanks for the reply Surfer 93.