swiched it around with a nether one and it wasent the injector it is a 95 */C with trac control the light came on sead it was off and the ses light came on and the car started to run with the miss need to get the inj noid to check the power to it have tried everything else any ideas

update no power to num 4 inj any help its not the plug would it have somthing to do with the trac cont

check power to it first with a standard ohm meter on voltage setting.

I don't see why the traction control would cut power to one injector. I would check the wiring. If that doesn't turn up a damaged wire, I'd suspect the PCM.

How is the traction control related to you failing injector? Clear this up for me, did you replace an injector for the 94 from a 95? or are you talking about the LSS in your sig?

If you want help here, clear up the confusion. Or go find another source.

The car is my 95 lss with the */c motor in it when it happend the trac control off light came on and the ses light came on so I turnd the t/c switch to on and the ses light went off. I have traced the prob to the ecm the power side of the injector works and there is no pulse from the ecm ran a test on the wire from the ecu and it is fine so that indicates to me that the ecu is bad any thoughts on this because this is a odd one :?:

Check the harness connector to the ECU for good clean connections, its always a good start.
Sounds to me like the fault is in the ECU for only one injector to act up seeing that
you already swapped injectors and the replacement did the same thing and the wiring checks out ok.
Just my 2 cents worth.........

checked it plug to plug ran 3 to 12 volt thought it and it was all ok so must be the ecu

I just can't think of anything else it could be. Find a junkyard unit it you have to and give it a try.

You have tried unplugging the battery for a while, right? I don't know if it would do any good, this sounds like more of a permanent problem with the ECU, but worth a shot if you haven't.

Definitely the injector driver within the PCM. I ran into this exact problem with a 1990 Bonneville SE. The power to the injector was fine but the switching on the ground side within the PCM (the injector driver) was shot. One rebuilt PCM from NAPA (I reused the old PROM) and it was off to the races.