brians356

I've perused a few open speedometer threads, only found the more common issues (lifeless, intermittent, or wagging) but mine is completely whacked out.

Sometimes it seems to work properly for a while (can't be sure how accurate it is though.) It also will stick at, say, 40 mph for a while. Other times it stays at 0, then when I shift into 5th it will suddenly climb straight to 100 and stay there.

But here's the truly whacky part: This morning it spun counterclockwise from 0 and all the way around the bottom (!?) to 100 and stopped there. (Obviously there is no stop post at 0 like most speedos.)

I'm hoping it is a bad connection somewhere (this car had squirrels chewing on wiring before I bought it) because the speedo head itself seems ok, it just seems to get bad signals.

Anyone ever seen anything like this?

Brian

PS
The tachometer works, but seems not to come off 0 until rpms get above ~1500 rpm, so at idle it indicates 0. Maybe this is normal for these tachs?

Bipolarcivic

my dx had a smiler issue what had happened when i replaced my tranny (auto) the sensor was filed with tranny fluid and was all over the place i cleaned it and its worked ever since then.

brians356

Well, the car does have a minor oil leak. Where is the sensor exactly?

Brian

Bipolarcivic

on a auto is right behind the temp sensor on the trans but on a 5spd i dont know.

brians356

Mine's a 5-sp manual.

Logan09

I have the same problem with my civic I just purchased. It's a CX, but has an RPM gauge in the cluster. It will stay at 0 and after a while jump to the current speed. The kid I bought it from says it also will climb to 100 and you have to "hit" the cluster or else it will "stick" on 100. Only paid $150 for the car so can't complain. So I am stuck with you on this too. Mines a 5spd.

brians356

It is even weirder. I was wrong, there is a "zero stop" post for the needle to physically rest against. Only now my needle is underneath it when I am not moving! I.e. if it tries to climb above zero it will be stopped by the post. So, it apparently went all the way up past 100, clockwise, and all the way around to the bottom of the post where it is stuck now. Either that or it jumped over post somehow (like on a very bumpy road if the needle is loose enough on its shaft?)

Anyone ever see a speedo needle get on the bottom of the zero stop post?

Brian

JuggerNaut-CTR

You should start by taking the cluster out and getting the needle back where it belongs.
While the cluster is out you can visually look to see if all the ribbons look okay. There are continuity tests you can do while its out as well using a multimeter and will be able to see if the ribbon has any power.

But im gonna tell you, more times than not, a whacky speedo is from the vss sensor itself is on its last leg, or even more common, the plug is loose/pins for the plug have corrosion on them/or the wire(s) to the plug aren't in the contacts anymore.

From my experience, it was simply the plug being loose and the pins were corroded. I tried cleaning them and it got better, but the plug still felt a little loose when you push it on the sensor. Went to the junkyard and got another vss plug and wired it in. Back to having a fully functioning speedo. Mind you this was found out after lots of multimeter testing from the cluster, to the sensor plug and all the way back to the ecu. Had also tried other known working vss's with no luck.

After you have got the needle back to its home. Take a paper clip and shove it in between the wire and where it goes into the plug. Doing this with the ignition key in the 'on' position, you will be able to see if the plug is getting power or not. If you don't know how to do any of this. Look up how to do it on google.

brians356

JuggerNaut-CTR,

Great info, thanks. One question: On the 5-sp manual, where is the VSS connector? I plan to try to get to it ASAP and check it out.

WRT the needle: Maybe if I remove all voltage from it it will rewind counterclockwise to its proper resting position? It has been all over the place during this adventure, I'd like to think it can get back where it belongs without pulling the cluster. (Have you a quick link to cluster R&R procedure?)

Brian

JuggerNaut-CTR

The vss is on the top of the trans directly below the throttle body.

You need to take the cluster out to get the needle back. Easy task, 15 min tops. 6 screws total, and a few connectors.

deschlong

iTrader: (8)

I second JuggerNaut's advice - excellent help and suggestions.

StraussBuster

I've had the same problem before. For me, it just turned out to be a 10amp fuse under the dash. I forget what it was labeled under.

Mad-Mike

iTrader: (1)

My eg would do something like that also. I remember one time I was driving around 25mph and the speedometer just kept going up and ended on the other side of the where the needle would sit at 0 and get stuck. Usually if I get up to 90-100mph the needle would fix itself and go back to normal. Also on cold starts the needle would stay at 0 and if I give it a little tap it would move.

jlk16188

buy a new VSS and replace yours. its not hard. sits on top of the tranny near the started like everyone has said already.

JuggerNaut-CTR

I love how people tell someone to just go buy a part before simple multimeter test are done to narrow the problem, as there are a handfull of reasons why the speedo wont work...

fleabag

The car is a '92, it has been my experience that cars that reach 10 years old need all of their electrical grounds worked on/cleaned. Usually the engine bay grounds go bad first then the cabin, since your car is so old, you're definitely going to have to do both the engine bay and cabin electrical grounds, though I'd start with engine bay first. At least that way you'll pick up some performance and MPG.

Important thing about cleaning up grounds is to scrub the bolts, washers, eyelits thoroughly so they're shiny. Don't scrape any paint. So if a bolt has a built in washer, the bolt threads need scrubbing, each side of the washer needs scrubbing and the underside of the bolt head should be scrubbed. Also if any ground is attached to bare aluminum such as the thermostat housing, be sure to scrub that part as well until it too is shiny (since it's not painted).

brians356

Thanks chaps, good stuff pouring in now. I will check VSS, engine grounds, and remove the instrument cluster to see about getting the needle back atop the zero stop, and also check the solder joints on the speedo.

JuggerNaut-CTR: Other than cleaning the VSS, did your last post imply a continuity or resistance test should be applied?

Also, since VSS is a critical sensor of the VTEC system (input to ECU deciding when to shift valve timing) would an impaired VSS causing speedo to whack out not also screw up the VTEC (and power/efficiency?) The car seems to run fine, and get good mileage.

Brian

crazyhouse2011

Buddy, take off your intake boot, put that aside, and look on the TOP of the transmission towards the back of it. You will see a sensor plug and a few wires going to it about the size of a quarter. That is your vehicle speed sensor. Replacing that is REALLY easy. Just unscrew and pull it out, and pull out the pin left inside the transmission, then rebolt the new one on, making sure to line up the new pin properly. Just watch a vid on youtube. I've done it, anybody can. Just scan your ecu first with the service connector by the glove box to make sure it IS the VSS, you should get a code 17.

redcoats1976

now im curious.my 93 del sol runs good,and has had a recent tuneup,air filter is clean and its a D16Z6 auto.cleaning all the grounds i can find in the engine bay will cause me to get better MPG,or is the auto tranny limiting me to about 27 mpg?it does have 248,000 miles on it.

fleabag

If you haven't worked on your electrical grounds, then I'd definitely do some work on them. I remember a guy on another website had a Civic VX which was getting only 35mpg and after I told him to clean up his electrical grounds and connections (check your positive connections as well, but grounds are highest priority) and to replace his pcv valve, his car now averages 60mpg+. It's true he did some other stuff like valve adjustment but the biggest gains mpg I saw were after he followed my suggestions. Valve lash adjustment did help quite a bit though. Just think in terms of what the car would be like if it were new aside from piston rings and whatnot, think why would a car get bad gas mileage. Also I wouldn't recommend replacing a bunch of parts before testing them as that's a waste of money with the pcv valve and grommet being the exception.

But yeah I've consistently seen much better performance and mpg with cleaned up grounds and the primary reason is usually due to the fact that dirty grounds means weak o2 sensor signal to ECU and if the signal is weak enough, the computer is forced to ignore it which hurts performance and fuel economy.

brians356

Re: Checking ECU code, I found this nice article:

https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/%5Bfaq%5D-ecu-codes-everyone-682412/

It explains how to decode the ECU light flash sequence, but how are the longer "P" codes transmitted using the flashing, or are they? (Article doesn't mention the "P" codes shown.)

Re: Check Engine Light:

My Check Engine Light sometimes comes on, sometimes not. When checking the ECU code, does the CEL need to be on?

I ask because it only comes on after driving for a while, and not always then (it may go "out" on its own, i.e. intermittent.) If the car is not running (as stipulated in the ECU article) the CEL probably will not be lit. Will I still get an error code from ECU?

Brian

deschlong

iTrader: (8)

Yeah, this confused me too when I got my first CEL and it went away after restarting the engine. But, it turns out the ECU "remembers" the last code it recorded and will output this when you connect the jumper.

I believe the "P" codes are for ODB2 and don't apply to your '92 Civic.

brians356

Update:

First, my frame and hands are too damn large, and I'm too old, to work under the dash of this car. After considerable joint pain I was able to part the two-wire (blu/wht, blk) ECU intercept connecter under the glove box. I made and inserted a simple jumper out of a paper clip, turned ignition switch "ON", and ... nothing. No code flashing.

The CEL came on solid for a couple of seconds (ditto the amber SRS) then went dark. All the red status lights stay solid as expected.

So this is disappointing. Why can't I get ECU code flashing? Could it be the ECU at this time has no errors to report? (I mentioned the CEL doesn't always come on. Do I need to warm up the car, wait for it to come on, then quickly stop the car and put in the jumper? Can I drive the car with the two-wire connector parted and dangling?)

Brian

brians356

Oops, maybe I selected the wrong connector. There are two side-by-side (slaved) connecters already exposed under the glove box, one a 5-wire, one a 2-wire. But apparently the one I want should have "brown" and "grn/wht" wires, and be behind a "kick panel" in front of the passenger-side door. Back into the torture chamber I go ...

Brian

deschlong

iTrader: (8)

Yeah, the connector *should* be blue. It is on my USDM '93 Civic. It's inserted along with another connector into a little rubber shield on that p/side, above the ECU, behind the bottom corner of the dash.