Weird fuel pump problem
I have a 1989 Ford Ranger. The fuel pump sometimes does not come on right away when I turn the key. I just try it another time or two and listen to the sound, and it comes on eventually and starts fine. I just never know. Most of the time there's no problem. But every now and then, this happens. Sometimes I have to turn the key back and forth several times before it comes on.
But the strange thing is: once I get it started, it runs just fine. Doesn't quit on me. It doesn't hesitate when driving faster or pulling a hill. That makes me think it's some other problem besides a failing pump.
In adition to this, once every great great while, the pump will come on and run for a long time, like 2 or 3 minutes if I don't shut it off first. And the engine won't start. Then I try again, the pump runs for just a couple of seconds like normal, and it starts fine. And it runs and drive just fine after that. That's happened maybe 3 times in the last couple of months.
Thing is, I don't want to go to the trouble and expense of replacing the pump only to find it's another problem.
I have replaced the fuel pump electrical relay, but that didn't make any difference. I replaced fuel filter,and didn't have the trouble for a while. But it returned. That was probably just happenstance.
I wondered if it might be the ignition key lock cylinder, as I think it could use a new one. But I don't see how that could explain the times the pump would run a long time but the engine still not start.
Anyone have any clues?