I noticed while waiting at a light that the RPM needle wasn't acting smooth like normal. is the jittery motion a warning for something else?
Whats up with a jittery RPM needle? (1 Viewer)
- Thread starter tea LC
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While your RPM needle was like that, did you notice the car idling rough...?
That could be the problem. Give it a tune up and change the PCV.
What I have noticed on some L/C is the MPH needle gets jittery as you accelarate or when you step on the accelerator and let go. I heard that that was normal and you are good as long as it still works
That could be the problem. Give it a tune up and change the PCV.
What I have noticed on some L/C is the MPH needle gets jittery as you accelarate or when you step on the accelerator and let go. I heard that that was normal and you are good as long as it still works
- Thread starter
- #4
no turn signals.
i didnt notice a rough idle at all but i guess it could have been very benign? -- i plan to do a tune up soon so i'll see if that fixes it -- the truck seems to run fine some im not that worried.
thanks for the feedback
i didnt notice a rough idle at all but i guess it could have been very benign? -- i plan to do a tune up soon so i'll see if that fixes it -- the truck seems to run fine some im not that worried.
thanks for the feedback
jumpy tacho
mine jumps around sometimes as well. usually about 500 or so RPM but the motor never changes speed. it happens on the highway and at stop lights. at first i thought it was a bad connection but the odd thing is, it always shoots UP about 500 RPM. at least i think it does. maybe it jumps back to normal? my tach reads 1800~1900 RPM right around 50MPH when the torque converter locks up. is that normal? stock tires and diff gears.
mine jumps around sometimes as well. usually about 500 or so RPM but the motor never changes speed. it happens on the highway and at stop lights. at first i thought it was a bad connection but the odd thing is, it always shoots UP about 500 RPM. at least i think it does. maybe it jumps back to normal? my tach reads 1800~1900 RPM right around 50MPH when the torque converter locks up. is that normal? stock tires and diff gears.
Hmmmm........i don't think your motor should be reving to compensate the turn signal! I see my alt. guage bump as the light flashes, but not the RPM. Mine had a little bounce to it and then i found out that the hose/pipe that runs from the air filter to the block had a huge crack in it from changing out the air filter. A tight wrap in duct tape fixed it and it runs smoother.
concretejungle said:
Listened closely this morning...it doesn't sound like the engine changes at all...and the movement in the needle is not noticeable unless you look down closely at it. It doesn't even move a full "mark" on the tach. I suspect there is a small vacuum leak somewhere.
another culprit might be that the tach is simply not very accurate at idle. i had to hook up a digital tach to my '03 VFR to set the idle. the analog tach was off by a hundred or so. sounds silly i know but on that bike, the idle makes all the difference in the world for low speed ride-ability.(sp?) set it too low and it will actually stall while stopping.
I get some funky stuff like that too. On the highway that is. I'll have cruise on and the needle will be at like 2300 rpm then it'll drop to 2100 rpm then shoot right back up. It does funky things. Dont know what its attributed to though
concretejungle said:
Hi, just as another data point, I started a thread about three weeks ago on this same subject in reference to when my turn signals turn on and off and the alt gauge and rpm gauge fluctuated ever so slightly. In my case I have a turbo timer that also reads actual voltage and amperage from the alternator so I was able to verify that in fact the ticking of the turn signal correlated with the ever so slight rise and fall of the alt gauge and the rpm gauge. The rpms did in fact fluctuate by about 35 to 45 rpms as measured by my digital rpm meter. If you think about anything less than 60 rpms, that is really immeasurably small and I imagine the average rpm gauge will not record or show this small of an oscillation. Another interesting observation is that if I closely and carefully watch my air fuel meter with no other accessory on, I can even detect an ever so slight fluctation of the engine rpm as the mixture goes from rich to lean and back again. I think in reality any accessory, any change in timing, any change in air fuel mixture, etc is bound to slightly change the engine speed or the alternator output etc, its just that most drivers and most gauges do not observe or do not attend to these slight fluctuations.
On another note, if someone's rpms are really jumping by more than 100 at any time, I would start to look at the TPS or vacuum leaks etc. I'm assuming this thread is asking about all the super slight fluctuations that occur throughout operation??? HTH
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I had the 500 rpm fluctuations for a while. I did the HG alone witha throttle body cleaning and they went away. I can't say for sure which one it is but I'd start with the throttle body cleaning. Another area that I got improved idling was with the front cat pipe. If you notice the pipe bolts to the manufold in 2 spots an then converges into one pipe. At that Y section I had a leak. The best way to check for this is to douse it with some soapy water while cold and have someone start the truck while you look for an air leak. I pulled my pipe and had it welded closed which really helped with the calming down the idle.
landtank said:
More good data going on here! Again, I assumed we were talking about fluctuations less than 100 rpms at the most. When you start getting the 500 rpm fluctuations, something is wrong with the TPS, the TB, vacuum lines, emissions equipment, etc. I would not want to speak for him but I think reffug had an exhaust leak on or around the same area and when it was fixed he had much smoother idle and much more power as well!?! You out there buddy where you can verify this?
I have the exact same problem with my turn signal. With my driving lights on with the turn signal my rpms jump up and down a bit at idle. Turn off the turn signal and the idle goes back to being constant and smooth. I attribute this to my Kaymar bumper with the additional rear turn signals. I figure it's taking so much juice that the it's effecting my ignition.
Now are there any solutions for this?
Now are there any solutions for this?
