quite a bit..... It will peg out all the way past 7 when getting on it.... Any idears on what it could be?????? I checked the connections at the distributor.....

On another note, what rpm's should I be at running 70mph with 2.73 gears???? Because my tach says the rpm's are 3750 @ 70???? Seems kinda high to me for an od trans.....

Thanks,
Tim

 

The tach is probably off.

As usual.

When these break, they always read high, sometimes outrageous. I've seen some that read more than twice the real RPM. Sounds like yours has joined alot of other people's.

 

Do I have to replace the hole cluster? or can I rob the guts out of another one?????

 

It's easiest to swap the whole cluster. But you can swap just the tach by itself if you want to do the extra work of taking it apart and putting it back rogether. It's about 15 minutes of work compared to about 40 minutes, cost will be the same I would expect.

 

Reason I ask is because I have the 140 spd-o in the car now, but have an extra cluster with the 130 spd-o.... Not that I ever go that fast but don't want to loose it..... Is there any differance between the 87 cluster's tach and a 89's tach that would cause it not to work before I start to dig into it this weekend????

Thanks,
Tim

 

The 87 is mechanical, the 89 may be electronic; in which case they won't interchange. I'm not sure what the changeover year was in the Camaros.

Other than that, they should swap.

 

pretty much factory tachs stink!especially 90-92z's,just put an autometer in it way more accurate.................

 

Eventually I plan to use all aftermarket Gauges, but want them to mount in the original dash spaces..... I like clean lines inside and outside the car, so for now I may just live with it until I can afford all the gauges at once.....

Anybody out there replaced all of the gauges, tach, and spd-o with the autometer gauges, tach, and spd-o????
A pic, and part#'s would be great.....

Thanks,
Tim

 

the 87's tach SHOULD slip into the 89s without issue. and visa versa..... i know a 88 tach fits in my old 82s dash...


take out the torx trim screws that hold the black panel on....

then take out the small screws holding the clear plastic on... (like 7 or 8mm)
move the plastic and take it out of the way


note that theres lil green circles over where the turn signals are while keeping a eye that you dont lose them..... take off the screws holding the black "rings" over the gauges..

undo the 3 screws around the tach... pull it straight out.. it just slides out to disconnect.... slip the new tach in...

everything goes in the same it came out.... be sure to put the lil green circle in for the turn signal....

 

yeah, i got the same problem. rpms show 1500 at idle... and when i step on it, it'll go past 7 grand and into the dark. i have a '90 iroc-z... i was just thinking about getting an autometer tach to replace the stock tach, since i really wouldnt know what to do to fix the tach in the dash. lol what would cause our tachs to act like this?

 

Yep, same thing as mine....
It would be great if it was really turning up that fast!!!!!!!!
And would hold together.....

 

Your RPMs should be at 2200ish for 70mph. My tach bounces all over the place would this be due to a faulty tach or something else?

 

only if he had the same gear ratio as you do...

 

Sounds about right for 2.73's......
Frickin highway gears.....

I'll be glad to get some 3.73's in the back this summer....

 

Same trouble in my 91 Z 5.7 Tuned Port car. The Tach worked perfectly until i installed a factory replacement motor. Then suddenly, same problem you guys are having. I was looking through my 1991 chev camaro service manual and it says there is a tach filter in line with the tach to help filter out "spikes and irregularities." It kind of makes sense because I installed an aftermarket Accel coil during the new install. I was going to try eliminating said filter, but i'll be damned if i can find it, even with a detailed schematic..... Hopefully I was of some help here; PLEASE let me know if any of you have any luck!

~Shotz~

 

Now that you mention it, I do remember having a filter on my 89 Iroc when I converted it to carb..... Seems like I remember it being in the harness somewhere along the fire wall.....
I'm glad you mentioned that..... I will try that out when I get home..... If it ain't freakin raining......

 

well the tach filter on my '82 is right behind the distributer mounted on the firewall. if you follow the tach wire coming off of your HEI, it should lead straight up to that, then down into the wiring harness.

at least thats how it is on my car.

 

Water, assuming your car is tuned port, please let me know if you have any luck. I have always been proud of the functionality of all my factory items and REALLY dont want to go aftermarket on the guages. Good luck and i'm glad I was able to aid in your search; Please let me know if anything pans out!


~Shotz~

 

I will check it tomorrow..... Had to wash all the mud off her today.... Damn rain......It doesn't help I live on a dirt road too....

I also have to find out why my original temp gauge doesn't work either, when I bought the car it had one of the cheap autozone temp gauges mounted under the dash right by my knee and I hate it.... Looks like I'll be busy tomorrow....

Sure would be nice to have a full set of autometer gauges in the dash..... I have seen pics of other cars with them in the dash and it looks real good to me....

Tim

 

Yeah waterstrw, the autometers are definitely nice, i agree. (costly tho....lol.) Listen, if you leave your ignition key forward (car not running) pull the lead off of the sender for the temp guage. It Should be a single green wire, near the front of the driver side head near the spark plugs. Ground the lead out and if the temp guage is ok, it read full hot while grounded and then the culprit will most likely be the sender. (Usually less tha 20 bucks.) Hope I'm telling you something you don't already know....lol. Lemme know how you make out!


~Shotz~

 

I was assuming it was the sending unit, but I will perform your test to check it.... Right now the temp gauge maxs out all the time.... Never comes down, not even when I turn the key off....