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Old 02-16-2010, 04:36 PM   #1
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Default Freakin bouncing tach

For the life of me I cannot get this **** to stop. Moved grounds about 5 times so far. Tach seems to almost stop responding, then bounces around a lot and somewhat settles down, sometimes its incredibly inaccurate. (Not like it isn't anyway) I've placed the 2 grounds from the engine harness to 2 studs on the intake manifold. Then, grounded the original ground strap from the 1.6(normally under the master cylinder) from the intake manifold to a stud on the chassis that holds on a clutch line bracket. I've heard it could be signs of the igniter going bad, so I posted a WTB, but does anyone think my grounds are shitty?

I need to sort this **** out before I install the MS I'm getting.
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Old 03-31-2010, 03:38 AM   #2
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Found my thread from ages ago. I STILL havn't gotten this **** to stop. and I give up. Where exactly are you guys putting your ground wires? I'm going to just copy a setup that is known to work...

2 igniters and its still there, cleaned and moved the ground bar thing under the master cylinder, new ground strap, under dash ground(next to hood release), looked it over 27 billion times...FML

Pics would be greatly appreciated.
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Old 03-31-2010, 03:58 AM   #3
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Abe, Have you thoroughly looked at wiring loom from the ignitor for any possible damage? corrosion or a rodents could be the coulpit =P

Upgrade to a COP set up and see if that helps ;D
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Old 03-31-2010, 04:20 AM   #4
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I just see the wires going into the big *** harness running along the fender...From the outside it looks ok. Obviously may not be the case inside .I may look later, but I want to make damn sure I've got a good ground setup first...
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Old 03-31-2010, 11:36 AM   #5
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Have you tried a new gauge cluster? You can find them at wreckers for cheap.
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Old 03-31-2010, 12:35 PM   #6
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Yeah, this sounds more like a problem with the tach itself. If it were a serious ground problem, you'd probably be misfiring like crazy. Sounds like the engine is working fine, though, and your only problem is the tach, no?

If you can borrow (or buy cheaply) an aftermarket tach and splice it into the tach wire, that would be a good diagnostic.


You've got a '92 with a '99 motor. What's your EMS situation? All stock 1.6 wiring and electronics (coils, igniter, etc)?
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Old 03-31-2010, 12:59 PM   #7
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Hmm, I'll see if I can borrow an aftermarket tach...
Yea, all the wiring is 1.6, on 1.6 ECU. MS coming soon though.

So no one sees a problem with my 2 grounds on an intake manifold stud and my ground strap going from the back of the head to a clutch line bracket?
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Old 03-31-2010, 02:09 PM   #8
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Quote:
Originally Posted by MartinezA92 View Post
Hmm, I'll see if I can borrow an aftermarket tach...
Yea, all the wiring is 1.6, on 1.6 ECU. MS coming soon though.

So no one sees a problem with my 2 grounds on an intake manifold stud and my ground strap going from the back of the head to a clutch line bracket?
Do you still have the main ground on the rear/side of the motor that goes into the metal shelf under the brake master? That's a crucial one.
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Old 03-31-2010, 02:20 PM   #9
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abe, i have an extra gauge cluster if you need to barrow it
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Old 03-31-2010, 03:06 PM   #10
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Ive also got mine, which we could swap out and take your car for a test drive to see if that's the issue. I think Andrew might be closer to you though.
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Old 03-31-2010, 05:48 PM   #11
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Nick you're only about 15 minutes from me.


Heres 2 pics. One is of the main ground strap that goes from the block to under the MC on 1.6 cars. Since I have a 1.8 I relocated it during the swap and it goes to the bracket pictured and to the back of the head.

The other pic is of the 2 grounds coming from the engine harness, and the manifold studs I mentioned before.

DustinB, is the ground you're talking about the main one from the block to the chassis?

From all the searching I've done, my bouncing symptoms are exactly like a bad ground symptom. I'll be cruising doing 75 and the tach will bounce from 3.5 to 4.5. At idle sometimes itll read 250 rpm.

Does anyone know if the under dash grounds are directly related to this or if they could cause this?
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