Wont go faster than 55 mph on the highway in 5th gear

[smokeeater88]

I am having troubles going faster than 55 mph in 5th gear on the highway with my 92 Ranger XLT . I just replaced the spark plugs, Spark Plug Wires , O2 sensor , Mass Air Flow sensor, Air filter, Idle Control Valve and replaced the gasket on the Oil Filter Adapter along with an oil change . I am trying to figure out why when I shift to 5th gear it will not go faster than 55 mph and sometimes the speed then drops to 45 mph ?

 

[chewy012]

Double check your spark plug wires. The drivers side is super easy to mess up and my chilton shows them incorrectly.

I mess up the connection every single time.
I can't quote the order, but a quick search on here will give you the correct order.

Sent from my XT1254 using Tapatalk

 

[RonD]

Welcome to TRS

Google: Ranger throttle cable mod

Throttle cable stretches over time so you no longer get Full Throttle, very easy fix


Change Fuel filter, cheap and easy, you might not be getting full flow when engine needs extra fuel for top speed.

Is it 55mph or can't go over 3,000rpm when in gear?
Computer has a REV Limiter when clutch pedal is down, there is a switch on the clutch pedal push rod, it prevents starting in gear but also tells computer when clutch pedal is pressed, some people by-pass this switch because starter motor didn't work


Exhaust, partially blocked exhaust limits RPMs and speed.
For more air to come in more air(exhaust) has to get out, limited flow out = limited speed

You can test that with a vacuum gauge, or have some one REV engine up and down while you feel exhaust flow out the tail pipe, if flow becomes steady but you can hear RPMs going up then you have some blockage

 

[rusty ol ranger]

I doubt its a stretched throttle cable, it would have to be really really REALLY stretched to keep you at 55.

Will the truck run faster then 55 in 4th? If so then that rules out fueling issues, or a plugged cat because youd be cranking more RPMs and it would be worse.

How many miles are on it? I would run a compression check and make sure it isnt just plain worn out.

Also, verify timing. Both ignition and valve, it could have very well jumped a tooth or 2 on the timing sprocket.