Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: Chaz on July 11, 2010, 01:31:05 AM

Title: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Chaz on July 11, 2010, 01:31:05 AM
I have a 1966 Cadillac DeVille convertible with a 429 engine,no A/C. It has been sitting in garage since 1982. I actually tracked down the last owner who have the car running (last registered) and he said that it was tuned up and running when placed in a garage back in 82. (Airforce, deployed back then and sold to restorer who let sit). It has not been on the road since. I poured some Mystery Oil in spark plug holes for a few weeks. Car currently has new spark plugs, spark plug wires, engine harness (wires were frayed) to key from American Autowire, starter, vattery (700CCA) and battery cables. Replaced fuel pump, now getting good fuel pressure to carb. I had a longtime mechanic rebuld the Carter AFB. The car is cranking slowly even with charged battery. I am getting a spark. I actually did get it to start once for a few seconds. Now it just turns over a few times slowly and stops. Sometimes it will intermittantly crank faster (very rarely), but most of the time just slow. I don't usually crank it too long as I don't want to burn up the starter (A few times within a minute, then stop for a few hours). I just changed the oil and filter, and again almost had it started.  With all the spark plugs out it cranks over really, really fast! While I had all the spark plugs out did a compression test on all cylinders. 95-110 psi on all except two. #5 was 125 and # 2 was only 55. I poured some 30 weight down #2 and redid test and show 150psi.

Replaced fuel pump, now getting good fuel pressure to carb.
I have also tried using a jumper battery, but it still won't start. Any suggestion on what else can do to troubleshoot the slow cranking and get this car started?

Youtube video to hear it:

http://www.youtube.com/watch?v=5npfNodOZh0&feature=player_embedded (http://www.youtube.com/watch?v=5npfNodOZh0&feature=player_embedded)
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: The Tassie Devil(le) on July 11, 2010, 05:17:53 AM
G'day Chaz,

Congratulations on finding the car.

Sounds like a bad grounding in the electrical system.

It turns over fast when there is no load, but putting the load back on by installing the Spark Plugs is creating a load that is possibly causing the Grounding lead, or the Positive Lead to not catty the required current.

Even the Starter motor Brushes could be worn and not properly contacting the Commutator.

Bruce. >:D
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Steve W on July 11, 2010, 06:10:27 AM
I watched the video...SOUNDS like your starter just isn't getting enough juice.
But you say even with a jumper battery its still the same. And the car has been sitting unstarted for over 25 years? I'm surprized it turns at all, so GOOD!

Seems like you're doing a lot of the logical things...fresh gas, fuel lines cleaned, rebuilt carb, plugs, wires, shooting Marvel down the holes,  etc.

And I would try a different starter. Make sure ita a heavy-duty premium starter, not one that you picked up at Pep Boys. (I'm just sayin')

Check all the wiring and the grounds again. Make sure you are getting optimum current to the starter.
You say you are getting spark. Play with the timing as you try to start it.

The encouraging thing is that you did have it started once for a few seconds.
Make sure the carb is primed...give it some gas...or some of that ether stuff. I'm only saying this because its really not turning fast enough or long enough, so you need every advantage to get it going.

Also, take off all the belts that run the accessories just to see if you can start it. Don't need a frozen power steering pump or water pump or alternator robbing what little cranking power you have. You'll check all of them soon enough anyway.
And, obviously, do not run the motor for any length of time without the water pump.

But after watching the video again...your starter just isn't robust enough to crank that beast!

Good luck and keep us posted!
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: TJ Hopland on July 11, 2010, 09:39:21 AM
Are you getting a good spark? I dont see any mention of doing anything with the ignition points.   Are you familiar with points?  If not let us know and we will give you a crash course.  Based on what the others are saying it does sound like one way or another there is a voltage problem which wont help your spark situation.   
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Fred Zwicker #23106 on July 11, 2010, 10:10:58 AM
I have a 1966 Cadillac DeVille convertible and experienced the same problem (slow cranking).  I went to NAPA and ordered two new battery cables in a heavier gauge wire than normal (these can be special ordered).  I cleaned all of the battery and starter terminals and in so doing, found the cable to the starter was just a little loose when I pulled on it, so I cleaned the terminals again and made sure that that cable was very tight.  I also installed a new battery, but don't think it was needed, once I found the loose cable on the starter.  Now when I turn on the key, the engine really turns over fast and the car starts immediately, unless sitting for awhile, when it takes time to pump the fuel into the carburetor.  Here are two pictures of my 1966 Cadillac.

Fred
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: TJ Hopland on July 11, 2010, 10:17:26 AM
If you have a farm and fleet sort of store near you that is often a place you can get some very heavy duty battery cables for a good price.   For sure you dont want the ones most stores have out on the shelves.    Most of the stores do sell 'OE' cables but they usually are not in stock.   I also doubt they would have a listing for something that old so you would have to randomly look up other models till you found something with the correct length. 
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Chaz on July 11, 2010, 10:19:14 AM
Wow, thanks for all the responses!   I just got the car 2 months ago BTW.  I have the entire history of the car too.  The guy in the Airforce was shocked when I tracked him down in Langley Airforce base.  He couldn't believe the car was still in the garage of the guy he sold it too.  The collector he sold it too died in 1993 and I bought it from his son.  

Some answers:
When I got, no spark, cleaned off the points with my wifes nail file and now getting nice spark!
Yes, car has been ssitting since 1980.  Close on Pep Boys, but Autozone :-)  I had them bench test and already tried a second one, but everyone I talk to still thinks starter.  I'm thinking of rebuilding the original as it turned over longer (but again slower).  Anyone know where to get a better, or high torque starter?  Was original a high torque?  
I will double check the ground.  Anyone know where the original ground location was on these?  It was originally on alternator when i got it, but now I put on frame.  
Yes, took off all the accessory belts yesterday, forgot to mention.   I went with a new 4 guage original, but it gets very hot in just a minute.  I have thicker battery cable, so thanks, I will try using that for POS.
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Chuck Swanson on July 11, 2010, 11:32:32 AM
Nice pics Fred!.  I forgot to add that I can't move the distributor.  I have sprayed PB on it, but even with hold down nut loose, it's stuck.  Any ideas on how to break free?  Thanks!  I joined the forum too :-)
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: TJ Hopland on July 11, 2010, 11:57:39 AM
If its stuck that indicates it has not likely moved in a while so its likely still set where it last ran so for now I would not worry about it.  Perhaps after getting it running the fresh oil and heat cycles will help it work loose.

Nice car collection.  The caddy is going to be quite the contrast to the others.  I went the other way, started with Cads then got an early mustang.   It was quite a shock to go to a car that basic but it was nice to be able to order new parts.   
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: 35-709 on July 11, 2010, 12:16:48 PM
I am with the camp that believes this is a ground problem, especially after reading that the ground was (improperly) connected to the alternator and you have moved it to the frame.  Attached is a picture of where the ground should be on a 1960 Cadillac, I realize this is a long way from a 1966 but as I remember my 1966 ground was in much the same place.  At any rate the ground should be shiny clean both the wire terminal end and where it attaches to the frame, and it needs to be tightened securely.  Click on the picture to enlarge it.  

Try this, run a separate wire like one side of a set of jumper cables, from the negative battery post to a mounting bolt on the starter, leaving the regular battery ground in place.  What you are doing is running a ground directly to the starter.  See what this does for you.  Also, if you do not have one or can't find one, run a permanent ground wire (the flat woven type do well) from the engine block to the frame.  Again, and importantly, make sure all of your metal to metal ground contacts are clean and snug ---- this goes for the positive wire too.  Good luck, and keep us posted, especially if you find it is something totally unrelated to all of the suggestions these posts have offered.   ;D

Geoff N.

By the way, a 50/50 mix of Acetone and automatic transmission fluid soaked well into the area where the distributor meets the manifold opening should go a long way toward freeing it up.  Put the mix in a squirt gun (edit: squirt can, not squirt gun), give it time to soak in and squirt it several times over a day long period.  Keep working it until it breaks loose.
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Otto Skorzeny on July 11, 2010, 12:35:11 PM
Instead of PB Blaster, try a 50/50 mixture of transmission fluid and acetone on your dizzy. Seriously.

We all learned that from the man above. (Geoff, not God)
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Dan LeBlanc on July 11, 2010, 08:50:47 PM
My question is, how low are you running the battery when you're charging it and how long do you charge it before trying again.  Extended, repeated cranking will drain a battery very quickly.  If you're getting down below 12.35 volts, damage starts happening to the positve plate.  If you're getting down in that range or lower, a constant charge of at least 10 amps for at least 24 hours will be required.  Anything less is not fully charging the battery and decreasing your cranking amperage available.

This is just another thing to include of keeping the connections clean and tight.  Yes, I do work for a battery manufacturer, so this is all stuff that was taught to me.
Title: Re: 1966 Cadillac very slow cranking
Post by: jerry Chase #17714 on July 12, 2010, 06:19:00 PM
I agree with the suggestions from Steve EXCEPT the idea of using spray ether.   This
product is intended for massive Diesel truck engines that can safely absorb the massive
"torque shock".

Using ether could very well damage a Cad engine.   Pursue all other avenues.



     Jerry
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Steve W on July 12, 2010, 09:01:22 PM
Jerry, I called it the "spray ether stuff" because I couldn't recall the actual name of the stuff that comes in an aresol can that you spary down the carb to help it start. I'm pretty sure it isn't ether at all, but I took a short-cut in describing it and I shouldn't have. Sorry for any confusion.
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Otto Skorzeny on July 12, 2010, 10:17:36 PM
Ya, that's ether, Steve. Don't use it.
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Chris Conklin on July 13, 2010, 08:34:57 PM
You'd be surprised how many things you can diagnose, troubleshoot, and find corrections for using a good electrical tester.
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no s
Post by: Doug Houston on July 14, 2010, 09:19:14 PM
One other thing, not yet addressed here. Pull the starter down, and see if you can get new bushings for the commutator end plate (or a new comm.end plate). and also the drive end bushing. Those bushings, when worn, can let the armature far enough off center, that it can't develop rated torque.  Also, check if there is a ground strap, connecting the engine to the frame, and if it's making good contacts.

And, while the starter is apart, make sure the brushes are in good shape, and that the commutator is clean and bright.

If the battery would be grounded directly to the engine block, it would actually be better, because it would eliminate any battery to frame to engine problems.

My '70 convertible has been in storage for around 30 years, and when I parked it, the starter barely pulled the engine over to get it going. The first thing that will be needed for it will be to get the starter off, and do to it, just what I said above. It has tired out bushings.
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: 35-709 on July 14, 2010, 10:16:49 PM
He did get another starter ---- at Auto Zone.  Probably not the best but if it was just the starter it should have performed at least a little better.

"And I would try a different starter. Make sure ita a heavy-duty premium starter, not one that you picked up at Pep Boys. (I'm just sayin')"
"Close on Pep Boys, but Autozone :-)"

So, how is it going Chaz?  Any news?
Geoff N.
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Chuck Swanson on July 14, 2010, 10:29:33 PM
I got some thicker battery cable I stole off off my 69 Coronet R/T that had battery in trunk.   Very thick.  I will cut a piece next week.  I replaced the battery with two other batteries I had, so I don't think it's the battery.  However, I need to check grounds as many mentioned.  Nothing on the starter yet.  Although I got my second starter from Advanced Auto parts, all the rest look the same from other vendors, stock Delco Remy.  I can't find a high torque version or even a rebuilt kit for original.  

I haven't got a chance to do much this week as getting my 67 Nova (pic below) show car nice and clean for one of the largest shows in East, Syracuse Nationals :-)  
http://www.rightcoastcars.com/syracuse-nationals.php (http://www.rightcoastcars.com/syracuse-nationals.php)
I will be back on the Caddy Monday  ;D

Thank you all for the excellent replies!!!  Wow!
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: william_b_noble on July 20, 2010, 11:28:22 PM
do you have a volt meter?  connect the meter across the ground and the + input to the starter motor (not to the solenoid, right at the motor) - crank car, see what it says - if less than 8 volts, you are losing too much voltage somewhere - find out where - measure from starter body to - terminal on battery, record result, repeat for the + tem to battery +, record result - fix what is bad
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Chuck Swanson on July 20, 2010, 11:33:24 PM
Great timing on the post.  I couldn't find mine, so I bought a new one this weekend.  I was just getting ready to test this week and was trying to figure out the best approach.  Thanks and I'll let you know the results!

As a side note.  I finally finshed restoring the gas tank today.  Had it cleaned and internally coated at a radiator shop.  When I got back I got rid of exterior rust (convertor/encapsulator/, used some glass on some of the dents.  Primed and painted with Tank Tone zinc paint.  Looks great!
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no s
Post by: mrspeedyt on July 21, 2010, 08:24:43 PM
gotta throw in the possibility that the timing chain or gear has slipped and valve timing is off. ( hope not for your sake....)
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no s
Post by: bcroe on July 22, 2010, 12:02:11 AM
Better yet, connect a voltmeter from the engine block to contacting DIRECTLY on the negative battery post.  Crank the starter and it will read the voltage lost in the ground wiring.  Connect again from the starter to contacting DIRECTLY on the positive battery post.  Crank the starter and it will read the voltage lost in the +12V wiring.  Ideal would total less than a volt.  The voltage might be jumping around quite a bit, so you might want to use an analog (needle) meter.  Bruce Roe
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Chuck Swanson on July 24, 2010, 04:32:15 PM
Just a few updates:

Took one of the valve covers off, removed all the spark plugs, and valves are moving up and down fine.  Turns over real nice with all plugs out.

Finally got the distributor loose after spraying some PB (Marked the original location with nail polish).  Took about a 1/2 hour to finally work free. It moves back and forth with ease now.  Put all the plugs back in and same thing, turns over slowly and stops after 3-10 seconds :(  I moved the distributor to various locations, 12 diff spots or so and same thing.  Battery fully charged.  I will do the electrical tests next.  
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Wubbywubster on October 26, 2018, 03:35:00 PM
I know this post is very old but I'm having the exact same problem.  l was wondering if you ever solved the problem?
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Chuck Swanson on October 26, 2018, 04:58:28 PM
No, I never did resolve that one, but I did remove that engine from that car for a rebuild ;)   Chuck
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Fred Zwicker #23106 on October 26, 2018, 10:34:34 PM
i had the same problem about  6-8 years ago, so I bought 2 new cables and a new starter from NAPA. I crawled under my 1966 De Ville and after grabbing hold of the long battery cable, discovered it was LOOSE! Since I had already purchased two new cables, I switched over to the new cables anyhow, making sure that the connections were spotlessly cleaned to bare metal and properly tightened. At that point I did NOT install the new started, as had a feeling that the problem was with the cables. I was 100% correct and am still running on the old starter and new cables.  MY car can sit for months and always starts right up every time.

By the way, NAPA has heavier cables available at an up charge, I am a believer that heavier cables will supply more starting amperage than the usual cables that are usually in stock.  This goes back to my pre-war cars that run on 6 volts. On a 6-volt system, a heavier cable is absolutely necessary.  On a 12-volt system, while not necessary, for a few extra dollars, a heavier cable just might be what you need.

I am selling this low-mileage older restoration - See Harwood Motors.com Car won 1st place at the Cleveland CLC Regional Show about 8 or 9 years ago and has been stored in our car museum since. See www.tipcars.us          Fred

Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Scot Minesinger on October 27, 2018, 08:56:06 AM
I agree with Geoff, same thing has happened to me as you and his suggestion is what I would have typed.  It is so easy; one jumper cable from battery ground to starter - please report back.  If the starter spins the engine fine with all belts and spark plugs in place you know this is the problem and that is easy to cure.  This symptom can seem like a bad starter and other issues. 

BTW, be sure oil pump is primed.
Title: Re: 1966 Cadillac DeVille convertible with a 429 engine, very slow cranking-no start
Post by: Maynard Krebs on November 08, 2018, 09:38:16 PM
My experience taught me to obtain rebuilt starters and alternators at a place near me that does the rebuilds in-house AND specializes in these items for big trucks, busses, and big construction equipment.   Those businesses NEED quality and reliability.   

I have never once had a problem with this place for which I do business.   I strongly recommend that all car owners buy from such establishments.