Hi all, I have a 93 Ranger, 4.0 Automatic, 4x4 single cab with only 121, 000 miles, it's in very good shape. My problem is that it doesn't seem to have the power that a 4.0 should have. I runs very good, the engine is quite and runs smoothly. In the lower gears it seem alright, but when it gets around 50 or above, it's got nothing. It's hard to get it to 70 with out holding it to the floor. It's not missing or anything, no warning lights. I had a 2.8 Ranger years ago, it was no power house by far, but it had more power than this 4.0. The question is, where do I start, does anyone have any ideas as to why the power is so low? Thank you, sorry this is so long.
jclintb@frontier.com

 

Check for vacuum leaks.
Seriously, people should put a vacuum gauge on their healthy engines to see where they land (on the meter) and to see how the tool reacts..
Then, hooking it up as a diagnostic tool is a more familiar operation.

As always, dose the tank with Techron before a stint of local driving. You never know which "crossed T or dotted I" might help.