This may be totally normal with old trucks and i may be a retard but hey so heres whats up. My trucks rpm stays at a certain level at certain speeds. Ex driving down the freeway last night at 70 mph. Truck never went below 2500 rpms. Even with foot totally off the gas Going 50 mph it stays around 1500-2000 even with the foot of the gas. Is this normal ?

 

Pretty much Yep. The engine has to make certain RPM for each gear to make a certain road speed- With mine (91 F-150, 5.8l, E4OD) 70MPH approximates 2000rpm in 4th gear.

You said that foot off the gas, it never dropped below 2500- But did your speed decrease? And your idle does sound a little high- Mine is usually around 1000 +-cold.

Scott

 

yea my speed decreased foot off the gas. At stops the truck idles around 1000 as well It does have a harsh idle i need to look at tho

 

Maybe your tachometer doesn't function just right. If you are sitting still and you gradually increase the speed of the engine does the tachometer seem to follow steadily? More important question, does the tachometer seem to follow along steadily as you decrease the speed of the engine when you are sitting still?

 

yea that could be true to. Ill have to look at it later today and get back to you