My Ranger has started to stutter violently and occasionally stall out at around 2k rpms while in drive. It doesn't happen when in park and I rev it up to 2k rpms. It happens in any gear while in drive. It also seems to be related to the weather but I have no confirmation on that. I can pull it out of the stutter most times by flooring it.

I'm not really sure where to start on this one. Couple things I was thinking:

  1. O2 sensor (changed this and still does it)
  2. Throttle position sensor.
  3. Timing a little off. (maybe one or two teeth off?)
  4. I just changed all of the spark plugs and re-gapped them to .044in

Any ideas before I start tearing it apart?

2 Answers 2


More than likely it's the throttle position sensor (TPS). What happens is they can get a dead spot in them. If you look at them, they are just a rheostat which varies the voltage as it comes through ... different positions means different voltages because of the amount of resistance which the electricity has to flow through. You get a spot in there where no electricity is being passed and you have a dead spot. This shows up at a certain RPM.

The O2 sensor doesn't cause this problem in the first place. It manifests other issues, such as poor gas mileage. Unless the thing just up and dies, it will continue to function without throwing a trouble code quite some time past when it should be changed.

If the timing was a bit off (you say a tooth or two), it would be all the time while you are trying to drive it, not just at a certain RPM speed.

Again, you'd see other issues if it were the spark plugs. Seeing as how they are new, you shouldn't be having any issues with them. I don't know off the top of my head what the gap should be for them, but .044" sounds about right or at least in the ball park.

  • A new TPS only cost 15$ so I went ahead and threw one in last night. So far so good, but it's intermittent so I need to drive it a couple days to be sure. Oct 20, 2014 at 12:11
  • Not the problem unfortunately. It acted up again this morning. Oct 21, 2014 at 11:43
  • Is the TPS connector clean? Also need to check to see if the wiring to the computer from the TPS is good, as well as the connector at the computer. Oct 21, 2014 at 16:04
  • I checked it thoroughly and everything seems good. Oct 26, 2014 at 15:37

See if there is a hidden fuel filter. Its inside a black plastic housing inside the frame rail between the fuel tank and the in-line pressure fuel pump. It has 4 fuel line ports, Best to unscrew the plastic bowl using a band type (oil filter) wrench being careful not to break the plastic bowl. It's hard to unscrew. I had to slightly bend my break line out of the way. The filter inside is 1 1/2" tall by 2 3/4" across.

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