4th Cylinder not firing.

Today I stopped at a stop light when it turned red car was running fine. As I startup after the light car running like shit I pull over and fine it is running on 3 cylinders. Ive had a problem before were #4 wouldnt fire and I could just unclip the plug that goes into the injector blow a bit to clean it out and she runs mint. Tried this and many other things nothing getting her to go now. I AM getting a very strong spark so it is not that.

Would this problem be caused by that actual clip or would it be further down in the harness?

Any help would be appeciated.

check the voltage by the injector clip

The wire could have broken on the harness somewhere.
I had and injector wire break for no apparent reason, about 6 inches up from the injector two years ago.
It caused the injector to intermintently cut out.

Your connector could be corroded, also check your spark plug for that cylinder

Could also be that the injector has just crapped out on you.

Had this same issue a couple times now on the Senta
One minute fine and the next, 3 cylinder city.

Adam