what causes my tacometer to bounce up and down and jeep feels like it is loosing power when driving, 1995 v6

Check the grounds for the coil and the tachometer.

HAVE YOU RECENTLY EXPERIENCED A LOW BATTERY/ BAD CONNECTION AND HAD TO BE JUMP STARTED OR CHARGED?

https://www.2carpros.com/questions/2003-ford-escape-turn-car-on-speedometer-tachometer-peg-return-normal-starting

HAVE BATTERY AND CHARGING SYSTEM TESTED

MOST POPULAR AUTO PARTS STORES WILL DO IT FOR FREE

THE MEDIC

I had been jumping a car weekly this Autumn, maybe that caused it, thank you Declan.

DISCONNECTING BATTERY HELP?

THE MEDIC

Jumping your car or another one? If another one, it can cause your alternator to go bad.

I have actually seen not only the alternator go bad, but the voltage regulator, fuseable links fry... Have the system tested as described. In addition, make sure power from the alt is making it to the battery. With a bad fuseable link, the alt can check good but the power from it can not get to the battery.

They have given good advice...

Have a Happy Thanksgiving, first, though.

One more thing: Vehicle computers have been known to become damaged by jump starting when the cables aren't removed as soon as the jumped car starts.

I replaced the computer 2 years ago, that was a big deal, I will try all suggestions, happy thanksgiving all, Deck

Thank you, you too. Let us know what you find out.

I changed the battery but jeep still has the RPM needle jumps at certain times mostly around 45mph then surges slightly for a few seconds then okay.

Have you checked the grounds? I've attached the schematic for the instrument cluster in 2 parts.

I took off and cleaned the IAC control sensor and so far so good after 2 days.

Good. Happy to hear it. Thanks for letting us know.

I replaced the battery, cleaned the IAC module and the jeep still does the same thing , the needle on the rpm bounces when I take my foot off the gas at around 40 mph, no engine lights on.

You have to have a loose connection or the gauge itself is going bad. Check to make sure all connections to the PCM are tight, clean, and not damaged.

Noticed today the rpm needle bounces before I move the car just after I start and idlying, any suggestions. Thanks Dec

Have you checked all of the connections as we have advised? As stated a few times, it's most likely either a loose connection or a faulty gauge.

Found the problem, the temp gauge was not working so I replaced the temp sensor on front of engine but did not know there is one on rear with a pin insert I hooked up that harness on sensor and everything is fine, no more tach bouncing or hesitating, the back Temp Sensor was loose

Cool. Happy to hear all is well now.

Closing thread.