tachometer very erratic? help pls

MattGSR · PostPosted: Thu May 06, 2010 11:38 am

So my tachometer is acting very erratic, it will jump all over the place sometimes, then other times wont work at all and sometimes work ok. Any tips on how to fix this? is this a gauge cluster/tach issue or something else? thanks in advance

CaptainTonus · PostPosted: Thu May 06, 2010 11:39 am

Does your car have a 91-94 ECU in it?

Enter · PostPosted: Thu May 06, 2010 12:03 pm

Quote:

Does your car have a 91-94 ECU in it?

not to steal his thread but i have a 92 ecu with link and tach works fine? should i be worried?

MattGSR · PostPosted: Thu May 06, 2010 12:14 pm

Quote:

Does your car have a 91-94 ECU in it?

My 1990 ecu crapped out so i swapped in another ecu, i think it was a 1990 ecu but i'll post the number here and recheck it. Any other thoughts?

CaptainTonus · PostPosted: Thu May 06, 2010 12:19 pm

Quote:

not to steal his thread but i have a 92 ecu with link and tach works fine? should i be worried?

Yah dude, your car is gonna blow up.

But seriously, that's weird. It shouldn't work. When I had a 91+ ECU in my Mirage the tach did very strange things, and that's totally normal for 89-90 cars that have 91+ ECU's.

Evotistical · PostPosted: Thu May 06, 2010 1:41 pm

lookup:
"tach filter"

CaptainTonus · PostPosted: Thu May 06, 2010 2:00 pm

Quote:

My 1990 ecu crapped out so i swapped in another ecu, i think it was a 1990 ecu but i'll post the number here and recheck it. Any other thoughts?

You probably put a 91+ ECU in there without realizing it.

ScottSpecV · PostPosted: Thu May 06, 2010 2:23 pm

My car does the same thing. I tried replacing the tach filter with one from the junkyard, but it still happens. I actually grabbed a couple, so I might try one of the other ones soon.

CaptainTonus · PostPosted: Thu May 06, 2010 3:05 pm

Quote:

My car does the same thing. I tried replacing the tach filter with one from the junkyard, but it still happens. I actually grabbed a couple, so I might try one of the other ones soon.

Yeah, the tach filter doesn't help. You physically have to open up the ECU and add a few things to it.

http://www.dsmchips.com/viewproduct.php?id=32

http://www.dsmchips.com/1990ecu.php

ScottSpecV · PostPosted: Thu May 06, 2010 6:17 pm

Sorry, I forgot to mention I'm running a GVR4 RS ECU. So who knows!

Evotistical · PostPosted: Thu May 06, 2010 7:23 pm

for me funny thing is I've swapped between 90 and 91+ ecu's and never had an issue with my tach

I'm running a 92 awd auto dsm ecu right now.

CaptainTonus · PostPosted: Thu May 06, 2010 7:26 pm

Quote:

for me funny thing is I've swapped between 90 and 91+ ecu's and never had an issue with my tach

I'm running a 92 awd auto dsm ecu right now.

When I had a 91+ ECU in my car, the tach would work perfect as long as my lights weren't on. True story. As soon as I'd turn on the lights, it would start tripping out. No idea what's up with that.

Enter · PostPosted: Thu May 06, 2010 7:56 pm

i thought my wiring was wrong at first but dsm link responds on my laptop so

MattGSR · PostPosted: Fri May 07, 2010 5:33 am

im still at work and cant post the cu number but where is the tach filter located and is it easy to replace?

CaptainTonus · PostPosted: Fri May 07, 2010 9:54 am

Quote:

im still at work and cant post the cu number but where is the tach filter located and is it easy to replace?

The tach filter isn't going to fix the problem, but it's located on the coil pack I believe.

4g61t.org

tachometer very erratic? help pls

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