thao2066

Hey, y'all. New here, but it seems like this place is the last place I can go to. I have a 97 Acura RL (Prem Nav). When it gets warm out, the speedometer will get jumpy. It will tack on about 15-20 on the speedometer whether or not I'm moving. All of the other meters and gauges work fine, it's just the speedometer. I'm still quite the newb mechanic. Any help or any insight is greatly appreciated. Thanks.

MyNameIsEarl

I kind of had this problem a while back when I upgraded my incandescent lights behind the cluster to the LEDs.

First things to consider would be, have you every opened up the instrument cluster or taken it out for any reason? Or, has it ever been removed by a mechanic for some sort of repair.

See, there are 5 control pins for each gauge. Some of which control the lights, and the others control the motion. Anyway, theses pins are very sensitive and although this isn't relevant, if you ever pull them out, they must go back in exactly as they went in and to the same torque as well.

I overtightened one once and it actually caused the gauge to cease to function (luckily I had a spare lying around). Another time (before I broke it) it wasn't tight enough, but it would make contact a few times I suppose and start jumping.

thao2066

Nope, but maybe I'll try to check that out when I change the backlighting. The bulbs are dead to where the needles are lit and working but I can't read any of the numbers or markings on any gauge. I want to change out those bulbs with that sticky and put some white vinyl wrap over some of the inside panels.

I was also thinking it might be a fuse? Or a speed sensor, but I don't know which one to start. There's two general locations, right? Mounted on/near/around the tranny and each individual wheel, right?

MyNameIsEarl

Fuses are located under the hood and are in a black cover. Also, there is an interior fuse box right by the parking brake pedal. But, a fuse would not cause the tachometer to get all jumpy. It may cause the lights behind the gauges to go out though.

What were you thinking of doing with the vinyl wrap?

Pro-Pilot

Do you know if the speedometer is electric or is it mechanical?

MyNameIsEarl

It's electric, why?

Pro-Pilot

Well if it was mechanical then a possibility could be the speedo cable going bad, used to happen on my land cruiser. Some graphite powder would always do the trick, but since its electric i have no clue

Sorry

MyNameIsEarl

Yeah, there isn't much on our vehicles than is mechanical. Everything is pretty much fly-by-wire, so to speak.

thao2066

Oh, yeah, I have a white car and with some black vinyl wrap I was going wrap the ridge of the hood, the roof, the mirrors, and all or part of the trunk. And I was going to cover up the wood trim and some of the dash on the inside with white trim. Kinda cheap, but something simple to look good.

I'm wondering if it's one of my wheel speed sensors? My car is throwing up the TCS light where I have to press the TCS button if I want to accelerate. I read somewhere that it does that if the car thinks that one wheel is accelerating faster than another. Could this be it?

MyNameIsEarl

Do you have any example pictures of the vinyl wrap? I'm not sure if it'll look to good on the inside. Something to take into consideration is to try to avoid taking the car apart unless you absolutely have to. Some plastic clips might break, some screws might be stripped, etc.

But, back to the tachometer. With the traction control system engaged, the light will turn on or flash if you push on the gas pedal too hard for a start. The flashing light indicates the TCS is working and reducing the power to the wheels. Now, if the light is flashing when you are not doing fast starts, that is certainly a problem.

thao2066

That's where I got the white vinyl. It turns out to be Oracal 631. Yeah, I get what you're saying. That's why I'm waiting till I get my LEDs for my dash so I can tackle it all at once.

This is the black vinyl for the exterior. This one is Oracal 970. Some other tutorials recommended this one.

Yeah, I tried to push the pedal, but the TCS light would flash until disengaged (I think disengaged).

Pro-Pilot

Is it just me or does the vynal look like Plastidip on that range rover.....

MyNameIsEarl

So when you do slow, normal driving starts, you don't have a problem, right?

The TCS indicator flashed during fast starts because it is compensating for wheel spin.

thao2066

I can't push the pedal to accelerate forward at all. All it does is the residual minimal movement.

I think for some odd reason I can reverse just fine. I can't remember or never tried.

thao2066

Maybe... I'm thinking I should have gotten gloss vinyl. :S

Pro-Pilot

I'm so confused by these statements lol

And I dunno, I've never seen a plastidipped RL, I guess it could look decent depending on the color

I think I see what your saying with the vinyl, you would have to cut it just right for the interior tho.

MyNameIsEarl

thao2066, I don't quite understand your statements.

Is your car drivable? Your "I can't push the pedal to accelerate forward at all. All it does is the residual minimal movement" makes it sound like all you can do with respect to going forward is the idle speed and when you press on the gas pedal, nothing happens. What exactly is going on with your car? Because at first I thought you just had a bad tachometer, but now it seems your problems are much more serious then that. You should consider getting them all taken care of before vinyl wrapping anything.

Pro-Pilot

I think he might mean that he cannot accelerate unless he turns OFF the TCS (in which case the light would be ON). The only speed he gets is the idle speed with the TCS ON.

thao2066

Yeah, sorry about that confusing wording.

Yes, I have to disengage the TCS (the TCS light turns on) to freely accelerate and then it is drivable. Otherwise, I get the idle speed.

And my speedometer is jumpy. Tachometer, gas gauge, etc. works fine.

MyNameIsEarl

Okay, I think you have two separate problems here. There may be a chance that whether it is due to driving or not that something got broken in your tachometer. Try going to a pick a part place to pick up a spare tach, just the gauge, don't let them try to sell you the whole cluster, unless you want to risk spending that much money. Also, if you get your hands on the gauge, be VERY CAREFUL with it! It is incredible fragile and sensitive.

I'm not really sure how to help you with the TCS. I would start looking on eBay for another TCS control module that would only cost you a few bucks. Buy it, install it, see if it fixes your problem. If that doesn't help try to get your hands on the wiring diagrams for the TCS from a mechanic.

I hope this helps.