Re: Tachometer w/ engine swap not working

[Jan van de Wouw <jvdwouw@xxxx>]

On 20-07-2002, Duke wrote:

> I know there are a few other owners out there that have done similar
> engine swaps in their DeLoreans'. (this is a '94 Chevy Vortec 4.3)
> I was wondering what changes you made to get the tach to work.
[snip]
> I believe the tach not working and the car not starting with the RPM
> relay in are related. I'm guessing its related to the white wire
> that goes to the RPM relay.
[snip]
> I know I could run another tach guage, but I'd really
> like to get the DeLorean tach working.

The wire you are referring to actually is Whithe w/ Slate stripe,
it comes from the ICU and is used for the Tach, the RPM relay and
triggering the ignition coil. If you did an engine swap, you
probably removed the original ICU, so the signal is non existent...
Even if you left it in, it won't generate any signal if you don't
have a proper pickup coil hooked up. The original engine has this
in the distributor and runs straight to the ICU over a shielded cable.

You COULD try hooking the wire to the input side of the ignition coil,
(opposite the resistors) but I will not take responsibility for this.
The signal wouldn't do you much good anyway, since it triggers from a V8.
I guess you would get the RPM-relay functional, but your tach would read
too high, as you get 4 pulses per rotation of the engine, while a V6 only
gives 3 pulses per rotation. You might put in a signal divider, giving
3 pulses for every 4 it gets, but I wouldn't know how to do that.

The trigger you need is to ground by the way.
Good luck anyway,

JAN van de Wouw
Thinking Different... Using a Mac...
Living the Dream... Driving a DeLorean...

#05141 "Dagger" since Sept. 2000

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