Speedometer, High RPM/Speed whine, High HC's 88 N/A
 

Hi all first post.

I have a 1988 Toyota Supra N/A which I just bought recently. Love the car. But I am having a few problems.

1. Speedometer worked fine until i removed the whole panel and put it back on, now everything works....except the speedometer. (It is connected in the back with the green thing. Any suugs on the cuase?

2. While driving on the freeway the other night I was fine until I got up to about 90 MPH/ 4000 RPM then a loud whining(?) sound came from the car. I let my foot off the accelerator and noise stoped at about 85 MPH. As long as I maintain right there I am fine. What could this possibly be? (Does not happen at higher RPM at lower speeds.)

3. Took it to go get smog checked and passed on the other two categories but on HC's (Hydro Carbons) it failed just over the max. Now my understanding is that if the Cat is bad then you would fail all three. Any suggs on what I can do to bring this number down?

4. This isn't so much a problem as it is I am curious (and if i did do it it'll probably be awhile) Is it possible to Change out the regular, boring Dash display for the digital one? If so, documentation?

5. Last but not least I get an error 52 (Knock Sensor issue) and looked and sure enough the nock sensor is connected to the block but the wire isn't connected to anything. Where is the wore supposed to be connected to? (remember mechanically illeterate so detail would be nie but any answer is welcome :-) )

Thanks for any and all help given!
Chris

Forgive me as i should prob wait longer for a reply but does anyone here know any answers for any of these ?'s

#1 - you most likey broke the tip of the cable while putting your gauges back in. Ive done it before. It means you will have to replace the cable. Its not all that hard, the worst part is getting the cable back through the firewall.

#2 - Thats a hard thing to pin down. its not RPM related so I would look into the drivetrain/suspension as opposed to the engine. My gearbox whines at higher speeds, but for me its any gear and is RMP related. you might have a bad 5th gear or ....man I dont know about that one more than what I said.

#3 - I would bet your getting a rich environment. Might try replacing the O2 sensor. Yes the cat being bad might give a different reading, but if you replace the cat it might compensate for the HC's a little better and allow you to at least pass smog. I have to admit though, Im not really much of a smog expert.

4 - Digital dashes were never made available to USDM...your not gonna find a LHD digital unit 'cause they never made em. Ive seen a writeup on converting one over...and believe me, if your not an EE and have a ton of time to spend making it work...just forget about it right now. You can make the stock gauges look very nice with custom faces, colored bulbs and other mods however, and all those are easily done.

#5 - Im afraid wiring isnt my strong suit, and Ive never actually looked at that side of my engine very closely...someone else will have to help you with that. Or you can look at the online TSRM found here: http://groundsky.co.nz/techinfo/TSRM/ and see if that helps.

Good rule of thumb on posting
 

Give it about 1 day, sometimes you will get lucky, and someone will post in like 5 mins, but usually prepare to wait a day.

After looking at the diagram provided I think I just found out why my HC'sare so bloody high and its so stupid its rediulous:
The second tiny hose from the charcoal canister to the BVSV wasn't connected. I couldn't believe that that could be the cuase of high HC levels but after reading the document it specifically states that the charcoal caister connections are what help reduce HC's...can you believe it? Now to just get my other questions (about the Knock Sensor connection and the strange sound) answered thanks man for your info so far :-) Oh and I should be more clear I have an automatic tranny with overdrive and that power mode thing

I think that just reduces HCs in the long run of the life of the car, But it may help. I dont know when the vaccum switch is open, But i think its just when the car is cold or ot. One of those two. Its temp related. I would say check the output reading from ure 02 sensor with a voltmeter, and then replace it if neccesary.

right and here is why this specifically is screwing me up cuz i just took another look and gues what? The bottom peice to the BVSV is missing. Oh and apparently hasn't been there since i got the car, something each Toyota Technician failed to notice. i amjust as much at fault though.

knock sensor
 

There is an article about rewiring the knock sensor here
http://www.supras.com/06/techcenter/display.php?QID=51
This article is for a turbo model though. The NA model is has only one sensor so you only have to string one wire.

And as for your rear end whine, Def sounds like a driveshaft bearing or your rear diff bearings. Maybe even the rear end fluid. Change it out and see if it helps. And if not, Replace all the bearings. Could be your trans tailshaft and/or bearings too. If its speed related its def the trans or back. Get your car on a lift and check for play and check it out to see if anything looks wrong or out of place.