RPMs going crazy!!

Hey yall. I noticed that when Im going 30mph in my Tacoma Prerunner, my rpms jump all over the place. Is this normal?

 

Does your vehicle actually speed up/down, or just the RPM needle? How much of a jump?

No, not normal. Clean throttle body and MAF. Easy and a good place to start.

 

Please define "jumping all over the place".

Can you hear the engine changing speeds?

If not, then something is probably wonky with the Tachometer.

 

Cleaning stuff without knowing the actual problem first is ill advised.

If the truck is going a steady 30 and the tach is jumping around, either its an instrumentation issue or the transmission is doing...something.

 

No. It’s not normal.

Can you tell us if the engine revs, the truck speeds up or it looses power, does it seem to just be the needle?

It highly unusual that the tachometer fails in these trucks. It’s usually the speedometer that gives problem.

Do you have any lights on on the dash?

FWIW, I don’t think cleaning a MAF Sensor will do anything for you in this case.

 

If the engine rpms do not fluctuate along with the tach....

Have you installed had any electrical components recently? I had an instance where abs/brake lights were flickering on the dash..... turned out to be a bad wiring harness from Crutchfield, there were frayed wires exposed from the crimp connectors grounding to the chassis.... point of the story is that electrical shorts can cause weird stuff to happen.