Sluggish 4.0 at freeway speed

[RangerDanger2]

Hello all! I have a 2004 Ranger with a 4.0L that I just purchased with 42K on the clock. It has great acceleration at low speeds, but when she gets up to 50 the power seems to drop and it's rather slow getting to 65-75 mph. I believe it has 3.55 gears in the rear end.

Should I be experiencing this? I would think a 4.0L engine would have plenty of power anywhere in the speed band.

Thoughts?

 

[RonD]

Change fuel filter, $10-$15


Check for partially blocked exhaust, best to use vacuum gauge on the engine for that
Raise RPMs to 2,500 and hold it there, watch vacuum gauge, if its slowing dropping you have blockage, it should stay high and steady

 

[RangerDanger2]

Change fuel filter, $10-$15


Check for partially blocked exhaust, best to use vacuum gauge on the engine for that
Raise RPMs to 2,500 and hold it there, watch vacuum gauge, if its slowing dropping you have blockage, it should stay high and steady

Thanks! I'll do both.

 

[RangerDanger2]

So I just wanted to follow up on the sluggish issue. I took my Ranger on a 100 mile trip and she did remarkably well. When I turned off the over drive, she really lit up, so I don't believe I have any problems.

I did check the axle and I do have a 3.55 rear end with limited slip (which I did not know), so I believe that's why she's not so lively at high speeds until the OD is turned off. Wish I had 3.73 gears, but oh well - I can live with it.