snwyvern

OK- I've successfully swapped out the points based distributor for the electronic ignition setup- Rewired the loom for the extra two wires, and my ignitors are working as intended (mounting them is another matter, however.)

My tachometer no longer works!

The wiring diagram in the manual for the '79 declares that the Yellow/Green wire gets connected to the positive terminal of the coil. However! The loom diagram (same manual-- Go Haynes.) says that the tachometer is to be connected to the negative terminal of the coil.

My questions are as follows:

First, if it's just detecting the bump / voltage dump to ground, should it really matter what side of the coil it's connected on?

And two, if it does, in fact matter-- Could I have fried something else by having it on the "wrong" side of the coil?

Any help is appreciated.
Thanks.

DivinDriver

iTrader: (15)

Factory wiring manual is a much safer resource; can be downloaded from a link in the section FAQ thread.

Proper connection point is negative side of leading coil, per the factory diagram.

Does the properly tach indicate voltage when you turn the key on, prior to starting... or is it completely dead?

snwyvern

Yes, the "voltage" key-on function works perfect. When the car starts the needle stays pegged at "0" RPMs. I'm going to go try fishing the wire to the other side of the coil. Film at 11.

Thanks again.

snwyvern

That did the trick. Now, if I can just get it to do more than idle at 0 degrees +/- advance... The afterburn is annoying the neighbors.

snwyvern

I really should just start a new thread for this....

I'm getting intermittent spark above 2000 RPM... I'm thinking that it could be a wiring issue, I'm going to try running a new positive to the coil from the battery mains. Any help is appreciated.

snwyvern

**** RETARD ALERT ****

... I had the Leading and trailing pickups backwards.

I fail. Hard.

RXDad

iTrader: (2)

No... You found the problem and corrected it with little issue. You win.

We all screw up.

RXdad

DivinDriver

iTrader: (15)

That's an easy mistake to make.

In other news, a '79 doesn't have pickups; it has points. Sure you don't have an '80?

snwyvern

I swapped out the electronic ignition from the points-based system. I believe the distributor is out of an 82... Spark is still erratic, but it was running.

DivinDriver

iTrader: (15)

Ah, you've got quite the hybrid system, then - - skipped over the remote ignitors completely.

74RX4

iTrader: (10)

A picture of your coils and distributor would be very helpful. Extra helpful if we can see the color of the wires connected to each of the terminals. Your car is a 79 model?

snwyvern

I believe everything is 'wired correctly,' however... I'm using a remote-ignitor setup, and my automotive wiring skills may be leading to signal bleed-over... When the ignition is in the on position there's 6ish ohms of resistance from the grounds I used for the ignitor and the negative battery terminal-- not a huge worry, but... Old car is old.

A "Pro" method to go at this point would be to simply replace the coils, wires, distributor and ignitors and start-over to ensure that the gremlins are out of the system... or borrow a scope to "see" the pattern the magnetic pickups to the ignitors are spitting out, etc...

But I have spark and that's a good enough starting point to me, off to the carb and therefore a new thread! (Thanks, everyone...)

DivinDriver

iTrader: (15)

6 ohms in-line on a 12vdc circuit limits your maximum in-series circuit current to no more than (i=e/r) 2 amps. I suspect the ignition system wants more than that, so that high ground impedance could be giving you weak spark.

Good test would be to measure for dc voltage between the negative terminal of the battery and your ground point when the system is on. Called "a ground voltage drop test," it tells you what proportion of your available voltage is being consumed by ground resistance. Ideally should be zero; realistically, you want less than a volt absolute max.