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Forum namePerformance/Engine
Topic subjectFinally installed my autometer tach but....
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=17696
17696, Finally installed my autometer tach but....
Posted by toykilla, Mar-17-02 07:52 PM
The RPMS are WAY WAY WAY OFF. The tach is showing me idle at about 2k but when I rev up to 5k the tach is at at 10k rpms. I know eclipse's are funny and the tach has to be calibrated. Thats been done before for a 97 Eclipse GS. I now have a 98 Eclipse GS so it should be the same calibration, why is it off so much??? I know its going to the right wire because I also have my HKS turbo timer to the same wire and the RPMS read just fine. Why is the tach off sooo much?? Also, after doing this, I noticed that my boost gauge reads around 5psi when im not moving. Whats up with that??? Its never done that before and idle vaccum is normal. The gauge is also right at the 0 when I shut the car off so I know the gauge isnt off but it shouldnt be reading boost when the engine isnt under pressure. Any ideas??
17697, RE: Finally installed my autometer tach but....
Posted by trickedeclipse, Mar-18-02 12:05 AM
hmm... that sounds odd. all i know is that when i turn mine off, the needle just follows gravity and falls downward (usually at 1500 or 2000 rpms when the car is off)it never goes back to zero.
17698, RE: Finally installed my autometer tach but....
Posted by trickedeclipse, Mar-18-02 12:06 AM
oh, my bad, you were talking about your boost gauge.... i wouldn't know about that yet. :-(
17699, RE: Finally installed my autometer tach but....
Posted by toykilla, Mar-18-02 01:06 AM
My tach never goes down to 0 either but its way way way off when car is running. I disconnected the battery to reset everything, hopfully that will fix something but if not Autometer will be getting a call from me later today.
17700, RE: Finally installed my autometer tach but....
Posted by silvreclipsers, Mar-18-02 01:11 AM
I don't know if this will help but I got this from the FAQs page

Q: I installed a tach on my car, but it only reads half the actual engine RPMs. Why?
A: NT's use a "direct ignition" system (no distributor, just computer and coil pack). To use a shift light or tach, you must grab a signal from the ECU (white wire on all years; on 95's the wire is located in the middle of the plug on the ECU; on 96+ it is located on the lower plug. Note that it's the solid white wire and NOT the white with yellow stripe).
The reason the tach is only reading half is likely because you grabbed the signal from the coil pack on the valve cover. There are two coils inside and one coil controls 2 cylinders. This is why the tach only reads half.
NOTE do not tie the 2 wires on the coil pack together or the car will not run and you are in danger of shorting out your ignition system
17701, RE: Finally installed my autometer tach but....
Posted by toykilla, Mar-18-02 01:33 AM
Mine is reading almost triple, at like 4-5k rpms the autometer tach is reading upwards of around 9k
17702, RE: Finally installed my autometer tach but....
Posted by FuSi0N, Mar-18-02 03:57 AM
Not to put anything down, but what is the advantage of installing one of those monster tachs? Does the stock tach have any weakneses or is it just for looks?
17703, RE: Finally installed my autometer tach but....
Posted by Thunderous_Talon, Mar-18-02 04:49 AM
easiest place to pull the tach signal is by removing the gauge cluster and there should be a screw back there in the middle behind the tach and tap it there. works fine there.
17704, RE: Finally installed my autometer tach but....
Posted by toykilla, Mar-18-02 05:59 AM
Just got off the phone with autometer and they said hook it up directly to the coil. I did and it works just fine now. The reason I have the tach is for the light mainly, however once I got it installed I saw that my stock gauge RPMS were about 2-3rpms off. LOL, thats probably why everyone on here hits rev limiter at 7200rpms and I was hitting it at 7500rpms. =]
17705, RE: Finally installed my autometer tach but....
Posted by toykilla, Mar-18-02 06:05 AM
>I don't know if this will help but I got this from the FAQs
>page
>
>Q: I installed a tach on my car, but it only reads half the
>actual engine RPMs. Why?
>A: NT's use a "direct ignition" system (no distributor,
>just computer and coil pack). To use a shift light or tach,
>you must grab a signal from the ECU (white wire on all
>years; on 95's the wire is located in the middle of the plug
>on the ECU; on 96+ it is located on the lower plug. Note
>that it's the solid white wire and NOT the white with yellow
>stripe).
>The reason the tach is only reading half is likely because
>you grabbed the signal from the coil pack on the valve
>cover. There are two coils inside and one coil controls 2
>cylinders. This is why the tach only reads half.
>NOTE do not tie the 2 wires on the coil pack together or the
>car will not run and you are in danger of shorting out your
>ignition system

That entire answer is incorrect. I had mine at first connected to the RPM wire of the ECU. My reading from autometer were almost triple what they should be. The reason the tach would have been at half what it should be is because #1. It hasnt be calibrated for our car. #2 The brown wire on the back of tach is NOT cut. Infact, the answer is the exact opposite of the correct answer because mine did NOT work until I hooked it up to the coil on the valve cover. Oh, thats what Autometer said to do so I doubt its going to short anything out. Its the black wire with blue strip directly to the coil.

17706, RE: Finally installed my autometer tach but....
Posted by drbalazo7, Mar-18-02 07:09 AM
when I bought my monster tach they told me to send it to Auto Meter and that they would calibrate it for our cars and so I did, and well they did and I have no problems with it..the only thing that I have is that when my car is at idle the needle shakes a lot and ver touches zero but when I rev it gets steady and runs normal




drbalazo@hotmail.com
jmorales@navsta.psasd.navy.mil

Thank you and have a Rice day!!
17707, RE: Finally installed my autometer tach but....
Posted by GorkoRacing, Mar-18-02 08:39 AM
The same thing happens with my tach. It shakes at idle but works fine otherwise. Some other guy with a tach in his eclipse has the shaking problem all he time it doesnt read the right rpms at all and shakes like a bitch. He called autometer and they said send it to them to have it calibrated. Why does his do this and mine doesn't. hmmm.
:D
17708, RE: Finally installed my autometer tach but....
Posted by toykilla, Mar-19-02 04:58 PM
Because yours in calibrated for our car.
17709, RE: Finally installed my autometer tach but....
Posted by vector_racing, Mar-20-02 12:34 AM
i never had mine calebrated, and mine works fine... first off the autometer tachs work for 4,6, and 8 cylinder cars, there r wires coming off the back, that either need to be cut or what not. i first set mine for 4 cylinders, and connected to the directly to the coil (per autometers instrutions), and I was off (lower) by exactly 1/2 my rpms (due to 2 coils), I later connected to the ecu signal, and it is dead on. It sounds like your tach as set for either 6 or 8 cylinders, and now only reading 1/2 the rpms (which is what you will read from the coil regardless of what autometer tells you) and your tach is set for reading 1/2 the rpms and it doubles them makeing you think that your rpms are correct. its all a number game, the instructions given above in the FAQ, are correct, and autometer just found a way 2 make the numbers work for your car. doesn't make it wrong, but i would assume a little less accurate. no big deal tho.

later