1987 2.5L Ignition Module Pinout help

[Hudini]

Hey guys, I am specifically looking for the tach output wire of the 1987 2.5L duke in a Century with DIS. I am installing a remote starter and wish to make the car start reliably. The car never came with a tach so not sure if its possible.

I have searched the forums but have not found anything specific. Also, any ideas on where else to look would be helpful. My Haynes manual wiring diagram does not specifically list a tach output, is there another name for this function? I did find a 1988 wiring diagram for a Fiero with a duke. It does show the tach output (Pin A on the larger of the 2 connectors). Not sure if the 1987 is the same though.

 

[rts]

I would think the primary leed would go to the dis depending on what type of tach your useing.On BB chevy motors we run down the track 1/4 mile we degree the tach with an optical eye yanked out from a corvette installed on the harmonic balancer so the ignition system is self contained.

If you have no way to install a tach on that system a optical eye from a coprvette will work for a tach but you have to degree it as you would degree a cam for true Rpm.When we have 800 to 1500 hp a ignition controlled tach is useless and untrue as most ignition controll tachs really are at any hp.We use a optical eye from a vette but I know the jegs and summit sells a system that is non ignition system also and equivelant.I would think though there must be a ignition system plug.I am just getting into buicks and tiny motors so I have no idea what your looking at.I can not even find the battery in my car yet(have not spent the time) and I think I stumped the techs with my tranny change on this site but yes you can hook up your tach no matter what.The way I suggest is for real rpm regulation but your not going to see those false high numbers to impresss yourself and others-You will see the true value from the crank.

 

[Hudini]

Thanks for the reply rts. Your idea is sound, but way more work than my little 4 banger needs. I found Pin A on an '88 Fiero with the Iron Duke is tach output (no color listed but my actual wire color is black/white stripe) , but not sure if the Century follows the same wiring. The C500 block Pin C3 is also tach input on the Fiero, but shows a white wire (guess I have to take the C500 apart to make sure) . I'm definately going to keep looking as I do not want to splice into the wrong wire!