1979 DeVille - What Do I Do Next?

[0maha]

I started this with a post in the "Want to Buy" section, and here we are a few weeks later and I've got a beautiful 1979 Coupe DeVille sitting in my driveway.

It made the trip back from Michigan mostly without incident.

The one thing that might need attention is the cruise control: It worked fine for the first 200 or so miles, then just stopped. I would throw the switch on the dash, and the yellow indicator light did not come on, and there was no cruise function. It continued like that for another 200 ish miles, then magically started working again.

Since I got home, it has continued to operate correctly.

Does that sound like a frequent problem? Any specific ideas on correcting it, or do I just sit tight and see if the problem recurs?

Pretty much everything else works correctly. There are a couple of known problems: The lid for the rear, passenger side ashtray is fouled up. I'll pull that apart and see what's what. The trunk pull down doesn't work at all. The previous owner said they "disconnected it because it kept running down the battery". Not sure what that means. I'd like to get that working properly at some point, although reading various threads here it seems like that is a frequent failure and most guys just ignore it. The one thing I'd really like to get sorted is the remote trunk release, which is also not working. In one of the threads I read, there was some talk of some guys doing a 3D printed model of the required parts. Any updates on that?

The trunk weatherstrip is a bit ragged and needs replaced. Any recommendations on a good source for that sort of thing?

Any thoughts on some general maintenance/reconditioning items that might need attention? I'm somewhat inclined to replace all the belts and hoses just because, assuming there are some of OEM quality or better available. I don't know when or if the plugs were replaced, so will probably do that. I don't know much about the car, actually. What sort of ignition does it have? Are there any service parts inside the distributor I should think about?

[6caddy2]

Jeff, great looking Tri-7 Cadillac!!

Well you have come to the right place for all your questions in this post, give it awhile and most questioned should be answered.

I can help on some of them, 1st though is what is your intensions with your car?!
1) local cruise nights?!
2) wanting to show the car at Grand Nationals, etc...
3) or just drive her and enjoy it as much as you can and do the above as well?!?
4) this should've been #1 question, are you mechanically inclined?!
5) and this is a big one, buy a service manual, and a body service manual 'Body by Fisher" manual, as these will be the most important parts you will ever own and buy while being the care taker of your car!!  "These can be found online"

With that being said,  you can find most of your parts online as well as right here in the for sale section of this forum! If these do not pan out post a question and photo of said part, and someone  here will be able to steer you in the right direction.
My personal 1st is the braking system on your car, complete go thru yourself, 2nd would then be the engine itself, complete tune up, etc..

To answer your question on the distributor; it is HEI, High Energy Ignition.

Glad to have you here, look forward to seeing more photos of that great looking 79 CDV.
                                                                                                                               Happy motoring, Joe

[0maha]

I guess I should give some background,  eh?

I'm pretty good with a wrench. Have a degree in Mechanical Engineering, and enjoy digging in and learning everything there is to know about my machines.

I'm mostly a motorcycle guy. Built the green bike from scratch last year, and rebuilt/modified the red one down to the last bolt last winter.

My biggest limitation at the moment is shop space. Wish I had more room to work on this big car.

As for my intentions, haven't really thought it through. Not into car shows or any of that. At the moment, I want to get this DeVille mechanically reconditioned to as close to new as possible. Cosmetically, its pretty good already, but I still don't have any interest in making it into a 100 point car.

After that, who knows? I think I bought it right, so I may sell it on. Or maybe we keep it and take it out for a cruise once in a while. It won't be a daily driver or a show car. Somewhere in between.

EDIT: Deleted a couple of pics of motorcycles I've built. Apologies for the infraction of the rules!

[TJ Hopland]

The ignition system uses an electronic pickup so no points to worry about,  just cap and rotor.

Cruise part vacuum and part electrical.  Most common electrical issue I have seen is a bad ground on the underhood unit with the speedo cables attached.  In many cases it grounds through the body, you will see a ground strap around one of the rubber isolation rivets that connects the main body to the mounting bracket.  The bracket also needs a good connection to I believe the fender in this case.    Other less common electrical issue is wear or damage to the wires from the button on the turn signal.  They feed through the column so if someone tilted the column a lot they could eventually be damaged.

I don't remember 79 deville specifically but typically the trunk release is a solenoid in the lid so its not directly related to the pull down.   The 3d printed talk I think was related to the pull down limit switch which could be what failed on yours, basically it never knew it was closed so stayed on.   The weatherstrip isn't likely helping the situation.   Steele Rubber or Rubber the Right Way would be where I would look, one of them likely has it.

[Dan LeBlanc]

No speedometer cables going to the cruise servo on this one. Just two vacuum solenoids-one to admit vacuum to the system when the cruise is turned on, the other modulates the vacuum to adjust speed.

I would clean the connections at the vacuum solenoids and the cruise computer mounted under the steering column (it's a red box) and start with that.

I've also attached the service manual for the cruise here. Your cruise system is in section VI

[TJ Hopland]

Oh ya forgot Cadillac went more electronic before the others.   Speed sensor was in the speedometer head that sent a signal to an electronic module which then ran the vacuum solenoids under the hood. 

[bcroe]

For 79 there is an optical pickup mounted in the back of the speedometer
with amp, which connects to a small red electronic module to run the
cruise.  That drives the throttle vacuum motor.  Have seen the module on
Evil bay, have one here also.  Bruce Roe

[0maha]

I've also attached the service manual for the cruise here. Your cruise system is in section VI

That's awesome! Thank you for the manual!

The problem has yet to reoccur, but if it does, I'll dig in and see about those connections.

[Kurt Weess]

I had a similar problem with my 78 Eldorado with intermittent operation of the cruise and it turned out to be the on / off switch.  The copper foil on the back of the switch would oxidize and loose contact with the small round copper connectors to the actual switch that passed through the foil.  I located the problem area and just put a dab of solder on the foil to connector interface and haven't had an issue since.