: 1981 Fleetwood Brougham with V8-6-4



My_favorite_Brougham
06-08-06, 09:22 PM
I know someone in the family who has an '81 Fleetwood Brougham with all the features like memory seat, mpg sentinel, light dimmer, CB, leather, and the V8-6-4 fuel injected engine. He is willing to sell it for $250 because he hit a deer and smashed the grill and headlight assembly, however the fenders and everything else are fine. Is this a good deal? I checked the local junk yard and there's a whole front end of an '87 Brougham for a surprising $50 that I think would fit the '81. Is it worth it for a good running car (only 90k miles)?

BTW...why did Cadillc stop making the mpg sentinel and headlight dimmer in Broughams?

brougham
06-08-06, 10:54 PM
That sounds like a really good price for it so get it. It shouldn't be that hard to fix it. They stopped using the gas mileage computer thing when they stopped being fuel injected. Probably with a carberator it's too hard to figure it out. And they didn't just stop making Broughams with the high beam dimmer. 1987 was the last year that they all had it.

77CDV
06-08-06, 11:16 PM
Are you serious?!? Go for it!!!! That is one sweet car for $250, and the work needed to bring it back is minimal. You'd be crazy not to get it!

I~LUV~Caddys8792
06-09-06, 12:22 AM
Get it!!!!

easymoney$$$$
06-09-06, 03:13 AM
That sounds like a really good price for it so get it. It shouldn't be that hard to fix it. They stopped using the gas mileage computer thing when they stopped being fuel injected. Probably with a carberator it's too hard to figure it out. And they didn't just stop making Broughams with the high beam dimmer. 1987 was the last year that they all had it.
......does anyone know why Cadillac quit making automatic headlight dimmers?

caddydaddy
06-09-06, 11:04 AM
......does anyone know why Cadillac quit making automatic headlight dimmers?

They are too sensitive to other lights like street lights etc. Most had sensitivity dimmers to turn down thier sensitivity, but I don't think that helped 100%. It's a cool idea, and with todays technology it would be nice to see it again, improved of course! :thumbsup:

Buick61
06-10-06, 06:52 AM
They are too sensitive to other lights like street lights etc. Most had sensitivity dimmers to turn down thier sensitivity, but I don't think that helped 100%. It's a cool idea, and with todays technology it would be nice to see it again, improved of course! :thumbsup:

They do have it again. IIRC, Cadillac and Lexus recently brought it out. Maybe it was Mercedes-Benz.

caddydream
06-10-06, 10:57 AM
I remember the V8-6-4. People said it was hard to fix. I think it would be a collector Caddy now because so many of them are in the bone yard.

I would say buy it if you have the patience for this quirky Caddy.

Oh, I do know a guy with a new Impala SS with V8-6-4. I'm sure it's a huge improvement over the original.

I~LUV~Caddys8792
06-10-06, 11:30 AM
It's neat to see how many innovative things Cadillac had back in the early '80s that died and were brought back with better technology by other companies! That's really ironic! And no one says GM can innovate...

Broughamadrosis
06-10-06, 05:48 PM
The auto-dim option dates back to the 50's when it was known as the Autronic Eye (http://collectibles.goantiques.com/search/images.jsp?id=774198&dealerSite=N) - the sensor was a pod mounted on the dash with a forward facing lense - reminds me of the alien from the original War of the Worlds movie...

They moved it behind the grill in the 60's... It was a POS back then too...

I had an 80's Lincoln behind me that had that feature... my tail lights weren't bright enough to trigger the dim - until I hit the brake lights - after two miles of the bright-dim game I was tempted to brakejob the SOB and put his friggin brights out for good... but I opted to pull over and let him pass - but not before I hit my brights to return the favor... :brutal:

Eldo1953
06-10-06, 06:49 PM
......does anyone know why Cadillac quit making automatic headlight dimmers?

They have it back now. It is called Intellibeam. :)

Buick61
06-11-06, 06:35 PM
Chrysler has autodim their 2006 Chrysler 300C Heritage Edition and it'll be a option on all 2007 300Cs.

77CDV
06-12-06, 10:27 PM
Of course, if you just d/c the wire connecting the computer to the transmission, the V8-6-4 feature is disabled and you have a straight 6.0L V8 again, just like 1980. Please tell me you're getting this car.

Craig

ilgoldstein
06-13-06, 12:14 AM
I have not heard anything good about the V8-6-4 system in these cars. I think disconnecting it would be a good idea.

My understanding is that it was an electromechanical system with the valve train and was problematic. The new systems rely more on the computer and fuel injection system as well as the valves.

Anyone care to add their personal experience (I've had none.)

DPGC23
06-13-06, 12:17 AM
What Was Wrong With The 864??
Dpgc23

77CDV
06-13-06, 12:35 AM
What Was Wrong With The 864??
Dpgc23

Put simply, GM got too far ahead of the available technology. The computer microprocessors available in the early 80s just weren't fast enough or powerful enough to do the job. Think trying to run Windows XP on a Commodore 64. The shift between 4, 6, and 8 cylinders was...abrupt, let's say, which made for a less than satisfying driving experience. And, the computers were so overstressed that processor failure was common, which caused the car to shut down and leave the hapless owner stranded. Ironically, the V8-6-4 only kicked MPG up by maybe 2 points, and increased mileage was the whole reason it was invented. So, not only was the system trouble-prone, it wasn't even very good at it's mission in life even when it was working right. It was symptomatic of GM's major (and continuing, IMO) problem: daring ideas poorly executed.

Craig

DPGC23
06-13-06, 09:55 AM
^^^

Ahhh, Perfect Explanation, Bein That Im In The Computer World,

Xp On A Comadore, Damm

Thanks

Dpgc23

BluEyes
06-14-06, 11:12 AM
What Was Wrong With The 864??
Dpgc23

Mechanically, the system is near bulletproof. The electronics just weren't as Cadillac-smooth as everyone expected them to be.

Ask around on the big-block engine forum, several people have them and love the feature, I'm surprised people are bad-mouthing it so much in this thread. There were even some people working to retrofit the system to the older 500/472 engines over on the cowboyseven boards (I've got a set of V8-6-4 rockers + solenoids waiting for just the same thing)

The Ape Man
06-14-06, 08:31 PM
Top of the list as far as mis-information goes. The poor old 8/6/4.
The 8/6/4 had strange manners. It vibrated while in six cylinder mode. This only happened during transitions and the engine never stayed in 6 for long. Some other ill manners were found in this system. One was the idle speed control which could adjust idle speed without warning. Quite un-nerving when waiting to pull out into traffic with light pressure on the brake pedal. There is more.....
Mechanicals were not an issue. Mechanics were.
The cars got a bad reputation and people started dumping them on the market and/or playing insurance fraud. Made for another way to buy a good car for a cheap price.
All the bad manners except the vibrating 6 cylinder mode were carried along the DEFI system to the later HT-4100. Same computer system, different engine. The HT-4100 would run like a fine watch as long as it ran (which was not always all that long). Same engine control system proved to work quite well in later years. Crated HT-4100s could be found stacked from floor to ceiling at Cadillac dealerships as warranty returns during the mid 80s. 368 8/6/4s generally were not.

My_favorite_Brougham
06-16-06, 09:08 PM
I think I am going to go ahead and get it. Maybe this weekend or the next. However, based on the feedback for the computer, I might like to turn off the 8/6/4 device. How would you do that? Is it as simple as flipping a switch or is it a $200 sevice job?

The Ape Man
06-17-06, 09:59 AM
Disconnecting the modulated displacement feature really won't buy anything in terms of reliability. The way to do it is to disable the connection to the 3rd gear switch which is located inside the transmission. There is a switch on the valve body that looks like an idiot light type oil pressure sender. It makes a ground connection whenever the trans reaches 3rd gear. That connection appears on the 2 prong plug at the side of the transmission. You can put a toggle switch in series with the wire or just cut it. The plug can simply be unplugged also but the other wire does something like provide downshift solenoid power or reverse lamp ground. Can't remember right now. I'd like to see someone who currently has one of these cars working properly who can take before and after fuel economy readings (actual fill-up fuel used and NOT the dash readings!!!) and report them here. I've read some pretty off the wall claims which need to be challenged.
The archives here detail the process for FWD vehicles also.

linearone
08-14-06, 09:24 PM
so can anybody actually tell us what wires to cut and if it will cause problems bigger that the revers lights out to unplug this connector? I mean if it is really just a snip or a plug to pull i will do so but if i need to get dirty to do this...yeck

I~LUV~Caddys8792
08-14-06, 11:21 PM
I read a story somewhere of an old lady and her '81 Coupe deVille...

Traveling behind a semi truck on a two lane highway...'81 is in 4 cylinder mode, she goes to pass the semi, car never comes out of 4 cylinder mode, car comes around bend at the '81 and the old lady can't get back in behind the semi, nor can she pass because she can't get it into V8 mode. Car is hit head on and owner dies..

CadiJeff
08-15-06, 01:20 AM
first...get the car, it sounds like a steal at that price.
second...the biggest problem with the 864(per the old GURU) is the emissions choked power loss in the engine but even then it has plenty of power to get out of its own way.
third...try it with the 864 enabled for a while then decide
fourth...the old lady needed to learn to use her friggin brakes!

N0DIH
08-15-06, 09:49 PM
I would love to get a V8-6-4 just to study the system!

linearone
08-16-06, 09:45 AM
so can anybody actually tell us what wires to cut and if it will cause problems bigger that the revers lights out to unplug this connector? I mean if it is really just a snip or a plug to pull i will do so but if i need to get dirty to do this...yeck

anybody remember which of the two wires it is to cut or place a switch inline with? I am not going to pull this plug and be without a downshift detent.

DopeStar 156
08-16-06, 10:21 AM
I read a story somewhere of an old lady and her '81 Coupe deVille...

Traveling behind a semi truck on a two lane highway...'81 is in 4 cylinder mode, she goes to pass the semi, car never comes out of 4 cylinder mode, car comes around bend at the '81 and the old lady can't get back in behind the semi, nor can she pass because she can't get it into V8 mode. Car is hit head on and owner dies..

............................brakes?

BluEyes
08-16-06, 03:02 PM
I read a story somewhere of an old lady and her '81 Coupe deVille...

Traveling behind a semi truck on a two lane highway...'81 is in 4 cylinder mode, she goes to pass the semi, car never comes out of 4 cylinder mode, car comes around bend at the '81 and the old lady can't get back in behind the semi, nor can she pass because she can't get it into V8 mode. Car is hit head on and owner dies..


That sounds like an urban legend on so many levels. Even with "only" 3.0L, if you are passing and give it enough pedal to downshift, it should move along well enough. Besides, if she died, how do we know that the car never got into V8 mode? These cars don't have black boxes or anything...

Anyways, if my understanding of the trans switch is correct, it sounds like the 3rd gear switch on my '70 in that it is only a sensor to tell other systems that the trans is in top gear and has no effect on the operation of the trans. Since it is an eletrical circuit, you can put the switch on either wire and it will have the same effect, but I would put it on the ground side which can be determined with a voltmeter.
The trans downshift function on a TH400 is done with a downshift switch attached to the throttle body.