: Correctly wiring the sparks on a 500

10-28-12, 10:15 PM
Before I bought it, someone with more enthusiasm than smarts worked on this 72 Eldorado. The red battery ground wire is merely annoying, but the starting motor only worked because of a hanging stray wire, and so forth . . .

Today I set out to replace sparks and wires, one by one. Thinking it a bit odd that consecutive cyinders on the same side of the block should fire one after the other (maybe they should; I really don't know), I went to the Chiltons in the back seat (or maybe it's the other brand; I've bought both).

I can't tell which direction is which in that diagram (does the wheel shown in the diagram mean the front or back of the engine, as compared to the car?), but whichever direction it is, it sure isn't how this thing is wired at the moment.

Before taking the carb out for rebuild, it was gettin a whopping 4 MPG. It blew 2% CO (1.2% allowed).

Is there somewhere I can find a wiring diagram or picture so that I can tell how they *should* be on here, instead of how they are (the carb also had it's vacuum lines wrong. I'm also pretty sure that GM didn't ship it with a wood screw terminating a vacuum line . . .)



10-29-12, 10:39 PM
I have an ign wire picture on the second picture of this PHOTOBUCKET
album, lower right corner.


Get a factory service manual, get the vacuum hoses renewed.

It sounds like the engine needs all kinds of help. Likely the timing chain is
shot; check it out. I assume tires are current. Every time I get a car, it gets new
front calipers, brake hoses, and front lines (304 stainless is good). Cause, I
don't want any big surprises if I jam on the brakes. I do the rear too, maybe
a little later. And gas tanks often start leaking, mine come off about every
15 years. good luck, Bruce Roe

10-30-12, 10:51 PM
X2 on what Bruce said about a factory manual....really the best spent money for information. Sometimes they can be found on Ebay.

Miklo II
12-11-12, 03:37 AM
Heres a diagram