Hi everyone ,

 

I am a new member here. Just purchased a 1974 260 that's spent 20+ years in the Texas hill country out in a field. Rats chewed through many of the harness, but I have been able to in most part patch it together, however I've run into a snag with whatever this mystery relay is over on the driver's side by the radiator. The plug on the relay side has a yellow,  blue/red ,black/yellow, yellow/black,solid black, and light green/black colored wires. On the harness side of the plug most of the wires make sense , apart from 3 wires that are black/ white of the same gauge . It's really a guessing game to where these wires go without knowing what this relay is. Any insights ? I've looked at a 260 diagram, but it looks completely wrong. Any ideas? This car has A/C as well as all of the factory interlock system 

EGR Relay

That's your "EGR Relay". It disables the EGR system and retards the ignition timing until the engine has warmed up enough to trip the water temperature switch.

That relay and the water temp switch are both located on the wiring diagram in the lower left behind the headlight (kinda like where it is on the actual car).

The EGR function portion is described on page EC-16 of the manual and the ignition portion is described on page EE-27.

And there you have the difference between the man of few words...

And me. 

Just now, Captain Obvious said:

And there you have the difference between the man of few words...

And me. 

Meh. I'm just too tired to dig through the FSM tonight.

Make sure the wires aren't shorted together and the engine should run without it.  It is not mission-critical.

Good luck.  How about a bigger picture of that desert relic?

@bret2094

17 hours ago, Zed Head said:

Make sure the wires aren't shorted together and the engine should run without it.  It is not mission-critical.

Good luck.  How about a bigger picture of that desert relic?

@bret2094

Thanks everyone for the replies. I've been printing the FSM off at home since y'all mentioned it the wires aren't shorted, I've cut the original electrical tape back along the whole harness to inspect the wires . 

The sat without sparkplugs for most of those 20 years, but a little atf/acetone got the engine unstuck, and it seems to be building compression, so I'll continue fixing the wiring and will probably throw some new plugs and wires/ fuel pump on it and see if it'll run this weekend. Here's a couple pictures of her. Interior is too rough to post lol

I would clean / flush the entire fuel system before attempting to start the car. Drain the tank and inspect the inside for rust. Make sure you don't have any split / leaking fuel hoses. And yes, new plugs and wires. Can't remember if the 260's came with electric pump back at the tank or not, but since it appears to have the dealer installed insulation on the fuel rail my guess is the electric pump is probably installed back at the tank too.

EDIT: Looking close the insulation isn't on the fuel rail, just on the line from the rail to the front carb. I'd still check for the electric pump back by the tank.

Edited March 28, 20195 yr by w3wilkes

12 minutes ago, w3wilkes said:

I would clean / flush the entire fuel system before attempting to start the car.Can't remember if the 260's came with electric pump back at the tank or not

I had planned to have the tank professionally cleaned. Ive peeked in there already, and it's not rusted, but it's got 10+ gallon of vintage varnish . Figured I'd unplug the electric pump and run all of my lines into a gallon jug to hear it run. The previous owner died, but his father said that he couldn't remember if the engine had a rod knock or not. Couldn't really tell anything by hand cranking, so I figured I would start her up rather than getting invasive and pulling the pan and rod caps 

3 hours ago, w3wilkes said:

I would clean / flush the entire fuel system before attempting to start the car.

This would include the carbs.  

You could probably hear it run with starting fluid but if you want it to keep running, idle, and rev, there will be some cleaning to do.

 Since the car has been sitting, plugs out, for some years and you've used Acetone to break it loose, it would be a good idea to squirt a little Marvel Mystery Oil (or equivalent) into the cylinders, turn the engine over using the starter (plugs out and valve cover off) until you verify good oil pressure and the cam is being oiled.