Tachometer Conections

[captainluigi]

Where on G50 engine would I attach connections for a tachometer?

Numerous Tech posts state the unreliability of accuracy of tach in instrument panel.

I would like to run a test & make adjustments accordingly.

Thanks

[Q45tech]

Consult 1, 2, or 3 ORSoftware Consult

The CAS has 360 pulses per rpm650 rpm = 10.83333 x 360 =3900 pulse per secomd = 0.000277 or 2/10% accuracy.

With an accurate frequency counter 3.9khz = 650 rpm.

Study CAS outputs.

The inside tach is nothing but a voltmeter looking at ecu derived 0>5 volts

[captainluigi]

Sooooo..., are you saying the ONLY method for a remote tach is consult 1,2, or 3 or software consult? That NO other method exists?

The fact that the instr. cluster inaccuracy prompted the original question.

[96Qowner]

Don't forget good ol' Q45.org

http://www.q45.org/checktiming.html

[captainluigi]

Thanks 96owner, lots of good info there. i review that material often.

I realize i am not the sharpest hook in the tackle box. That said, how does that info tell me how to temporarily hook up a tach to compare tach in insrtument cluster with one of known calibration? Setting the timing is not what the question refers to.

Someone has done this I would think.

[96Qowner]

Brain fart on my part, Captain, sorry. I was thinking timing connections. I vaguely remember some discussion last year about where to get the signal for a tach.

[qsiguy]

On my '94 use...

Black/green wire on terminal #24 at the TCU

OR

Black/green wire on terminal #7 on the ECU

not sure if the '96 is different.

Of course this is the same source the OEM tach uses so maybe you dont want that.

[captainluigi]

"No worries'', At least we didn't mistakenly send super secret missle parts to Taiwan!

I searched & re-searched again but found no info. I guess we stupid & ignorant key -billies without Consults will just suck hind tete til the Q gods choose to reveal.

Me thinks some of the Q gods are just a little over stuffed with themselves.Always so eager to expound so much theory, statistics and raw numbers while we under shade of palm tree must rely on the empirical.

So there!

[captainluigi]

Thanks qsiguy, I'll research that. At least that is some helpful info for the Consult 1,2,3,4,5,&6 challenged.

[qsiguy]

I actually had that diagram sitting in front of me when I read the post. I was just tapping in to the tach wire at the TCU last night to wire up the tach input on my Zeitronix wideband O2 sensor.