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Help !! - 1962 Coupe severe hesitation / no power

Started by rustytractor, May 26, 2015, 02:39:21 AM

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rustytractor

I've gone away for a couple of days and taken my '62 coupe as it hasn't had a decent run for a while.

In typical "old car" fashion it's decided to play up and run like c**p which is no fun and really embarrassing so any rapid responses would be really appreciated.

It starts fine and idles perfectly but when on the move it's hesitating and pulling back really badly, particularly from standstill and at low speeds such as pulling away from a junction. Once on the move (over 30+ mph approx) it's passable but still not right and really lacking in power. There's an irregular faint popping sound coming from the exhaust which sounds like unburnt fuel igniting - the cars not exactly undriveable but not far off.

I've suspected the coil was well passed its best for a while so decided to replace it before we left the other day but it ran worse with a new one and then ran ok when I put the original one back on. The new replacement required an external resistor, the original one's been painted so no lettering is visible but it is an original AC Delco coil.

I've been down the "it appears to be fuel related" road before with another 62 and that ended up being the coil, I'm just a bit puzzled because the new coil was worse - possibly it was just a bad new part ?

One query is with the internal distributor wiring to the points. I have a few basic tools with me so checked inside the distributor and there are 2 wires going to the points, both of which have open spade terminals.  Neither is screwed down to anything and both are sort of pushed in between the curved sprung steel side of the points - it's a bit hard to explain but I don't recall having seen wiring done this way before. All I know is it seems wrong to me as the contact can't be that great.

Ive got tools but no spares so may be a bit screwed and have to try to limp the 100 miles home as is or get the car recovered if it gets worse.

Thoughts and opinions welcome.
Too many cars - too little time !!

Roger Zimmermann

The contacts you are describing are typical from that period and there is nothing wrong with them. Has your distributor a Pertronix system? On one of my cars, I had the same symptoms and thanks to a supplier who told me that Pertronix system could crate a similar problem I converted the distributor back to points and condenser.
If you have points, the condenser could be bad.
1956 Sedan de Ville (sold)
1956 Eldorado Biarritz
1957 Eldorado Brougham (sold)
1972 Coupe de Ville
2011 DTS
CLCMRC benefactor #101

rustytractor

Quote from: Roger Zimmermann on May 26, 2015, 03:12:04 AM
The contacts you are describing are typical from that period and there is nothing wrong with them. Has your distributor a Pertronix system? On one of my cars, I had the same symptoms and thanks to a supplier who told me that Pertronix system could crate a similar problem I converted the distributor back to points and condenser.
If you have points, the condenser could be bad.

Standard points, no pertronix.

I replaced the condenser when I swapped the coil a couple of days ago. I'm going to try to bypass the 12v wire from the ignition switch to the coil to see it the ignition switch is playing up.
Too many cars - too little time !!

Scot Minesinger

The popping sound can happen with timing being off, but since it ran fine before seems like it could not have gotten out of timing since last good run.  This is the last year of the all metal timing sprocket.  A vacuum leak is likely because that can influence timing. Look for a compromise in a major vacuum line, maybe going to brake booster or something, a hissing sound.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

russ austin

Condenser, points, dist cap, vac leak,  bad plug wires, numerous causes.
R.Austin

Dan LeBlanc

#5
On the coil thing - these cars have a resistor wire in the ignition circuit. The externally resisted coil you have is correct and should work without the need for an additional external resistor unless the resistor wire has been removed from the car at some point.

When was the last time the points and condenser were changed, and the dwell and timing checked?
Dan LeBlanc
1977 Lincoln Continental Town Car

curly

Have you checked the vacuum advance for operation?  I've experienced cars that idled perfectly but were complete dogs until 25 mph or so, and then they were fine.  In all 3 cases, the vacuum advance had a bad diaphram.

T Lewis

Tom Hoczyk , CLC 14044

I have installed Pertronix on my 1939 LaSalle (6 volt/positive ground) with extremely good results.  So good, in fact, that in the last 2 weeks I have installed them in my  1954 and 1960 Cadillacs, so far with equally good results.  The nice thing is that once it's timed, you need not ever retime.  One thing, though, is that on my 1960 I discovered the advance plate to be gummed up and not moving.  Spraying in some good cleaner and gently wiggling a tab on the side of the plate with pliers got it moving again.  After that, lots of oil, especially along the distributor shaft area and I was back in business. 

As both cars had distributors near the firewall of the car, they are extremely difficult to work on unless you remove them from the car.  Set the rotor position to the #1 cylinder before removing it from the car.  Of course when you reinstall you will have to get the gear and oil pump drive lined up properly again.  No worries if you get it off a tooth, but you will have to lift the distributor out a bit to enable you to get the gear drive tooth into the proper position for timing purposes.  I had to do this two or three times, even though I thought I had it right.  It's a pain, but nothing insurmountable. 

By the way, a VERY important bit of info if you have a distributor after 1956 that has the centrifugal weights at the TOP of the distributor, just below the rotor:  The Pertronix instructions state that if you have upward thrust action in the distributor shaft that exceeds .060" above the Pertronix sensor, you must shim the gear from the bottom of the shaft.  IF YOUR DISTRIBUTOR ROTATES IN A CCW DIRECTION, DO NOT NOT NOT SHIM!!!  I ruined my original distributor in the process of removing the pin that holds the drive gear on.  The natural CCW action of the shaft ensures that there will be no upward thrust on the shaft anyway.  I had to replace my distributor, even after a machine shop did a great job of straightening the shaft.  A bind still existed that threw it out of time.  I don't know why Pertronix does not include this info with their instructions, but they don't.  I could have saved many hours and dollars if I had known in advance.  Hope this info helps.
Tom Hoczyk

rustytractor

#8
Quote from: Dan LeBlanc on May 26, 2015, 07:59:03 AM
On the coil thing - these cars have a resistor wire in the ignition circuit. The externally resisted coil you have is correct and should work without the need for an additional external resistor unless the resistor wire has been removed from the car at some point.

When was the last time the points and condenser were changed, and the dwell and timing checked?

To be honest I'm not 100% sure - timing etc was checked Nov 14 but the cars had almost no use since. In fact I've done very little mileage in the car - leads are new, plugs are recent and were cleaned and gapped in November. Distributor cap looks new, the only thing which looks old is the coil. The problem has now got worse so I'm stuck by the side of the road awaiting recovery.

This morning I started the car and took a live direct from the battery to the + side of the coil. It ran worse.

Could be worse - at least it's not raining !

Tomorrow I'll check everything over and try to resolve the problem.

I've got a working 390 distributor, coil and carb from my '59 in the workshop - I'll prob swap them into the 62. If the problems resolved I'll work backwards until I can identify which components are at fault.
Too many cars - too little time !!

Caddy Wizard

This is most likely one of two main culprits:  fuel or spark (sorry to state the obvious).  Many times on old carbureted engines, symptoms that we assume are caused by faulty ignition or bad carbs are really inadequate fuel supply from the fuel pump.  I have often had the experience of a good carb and good ignition system undermined by an inadequate fuel flow to the carb (usually in warm weather when the engine is fully warmed up).  This results in an engine that will start okay and will idle reasonably well, but has little power and suffers from hesitation.  An electric fuel pump has been my best investment.


Check the usual spark issues (points, condensor, coil, etc.).  But my bet is that an electric fuel pump, either running in auxiliary mode or all the time, is the ticket...
Art Gardner


1955 S60 Fleetwood sedan (now under resto -- has been in paint shop since June 2022!)
1955 S62 Coupe (future show car? 2/3 done)
1958 Eldo Seville (2/3 done)

Jon S

My opinion is an electric fuel pump is a mask; not a fix and since these cars run very well with the mechanical pumps that were designed for them, I would rather fix the problem correctly than masking it with a foreign item!  JMHO
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

rustytractor

Quote from: Art Gardner  CLC 23021 on May 26, 2015, 03:00:33 PM
This is most likely one of two main culprits:  fuel or spark (sorry to state the obvious).  Many times on old carbureted engines, symptoms that we assume are caused by faulty ignition or bad carbs are really inadequate fuel supply from the fuel pump.  I have often had the experience of a good carb and good ignition system undermined by an inadequate fuel flow to the carb (usually in warm weather when the engine is fully warmed up).  This results in an engine that will start okay and will idle reasonably well, but has little power and suffers from hesitation.  An electric fuel pump has been my best investment.


Check the usual spark issues (points, condensor, coil, etc.).  But my bet is that an electric fuel pump, either running in auxiliary mode or all the time, is the ticket...

Art, when I got the car the standard fuel pump (which was no more than 12 months old and had hardly been used) failed so I replaced it with a new one - the car has covered less than 1000 miles since so I doubt the fuel pump is the issue in this case.

This is further reinforced by the excess fuel which leaked from the exhaust pipes when being winched onto the recovery truck.

I'm pretty certain that adequate fuel is being pumped in, it's just not being burnt properly.
Too many cars - too little time !!

Jon S

I'm in agreement it is not fuel-related by either an ignition or timing advance issue. I just changed out my coil, points, condenser and set dwell and timing and used Blue Streak's best points and now have a strong spark and exceptional power. BTW, ventilated points are the way to go. Rock Auto still carries the good ones.
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

35-709

"I've been down the "it appears to be fuel related" road before with another 62 and that ended up being the coil"

If you have excess fuel running out of your exhaust pipe I would suspect the needle and seat in the carburetor is sticking, or it has a piece of trash under it.  Not uncommon with a car that has sat for a while.  You may be suffering from a flooding condition.

As someone here has said, if you think you have an ignition problem --- check the carburetor.  If you think you have a carburetor problem --- check the ignition.
;D
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

rustytractor

Quote from: 35-709 on May 26, 2015, 07:24:43 PM
"I've been down the "it appears to be fuel related" road before with another 62 and that ended up being the coil"

If you have excess fuel running out of your exhaust pipe I would suspect the needle and seat in the carburetor is sticking, or it has a piece of trash under it.  Not uncommon with a car that has sat for a while.  You may be suffering from a flooding condition.

As someone here has said, if you think you have an ignition problem --- check the carburetor.  If you think you have a carburetor problem --- check the ignition.
;D

Or maybe just wait until it bursts into flames then claim on the insurance and buy another one ? 😜

Too many cars - too little time !!

Jon S

I would think the excess fuel is from cranking/flooding the engine with no ignition to ignite it as opposed to a sticking float or needle/seat.
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

Joe V

#16
Had the exact same problem on my car.  The symptoms point to the fact that the coil is not charging enough in between plug sparks so that it can deliver maximum power to each plug each time they fire.  When you give it the gas the engine calls for the coil to discharge faster (obviously) requiring it to complete the charge and discharge cycle faster.  With a compromised circuit providing power to the coil, there is not enough juice flowing to support the building charge/discharge cycle.  The result is minimal or no spark, unburned gas in the exhaust, and the popping sound when it ignites as other cylinders exhaust valve open.  Then as the car evens out and shifts RPMs go down and the coil can charge minimally to keep it running.

Given you have a new coil, my bet is on the circuit that charges the coil from the distributor.  My problem was lose wires on the points and if yours are just stuffed in to some part of the points or plate, the connection will not allow enough current to flow to the coil. You can't rule out simple things like point gap and point rubbing block wear but the later would not just happen after the car sits a few months.   

Other things to check are the circuit in distributor, continuity of the wires going in and on the inside, insulation on the insulated ignition terminal to make sure it is not grounding out - wiggle it to see if it is loose or broken.  After that check all wires going to the distributor from the ignition and then trace backwards to the ignition key circuit. 

Jon S

In the 1970's, Delco redesigned the points and saved money by eliminating the screw that secures the 2 spade wires and replaced it with a pressure spring loaded fitting in which the 2 wires were secured only by spring tension. It appears that is what you have and it is correct.
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

Joe V

Quote from: Jon S on May 26, 2015, 08:31:08 PM
In the 1970's, Delco redesigned the points and saved money by eliminating the screw that secures the 2 spade wires and replaced it with a pressure spring loaded fitting in which the 2 wires were secured only by spring tension. It appears that is what you have and it is correct.

Not sure how they would have used cheaper 1970 points in 1962, but I don't question the engineers that built these cars back in the day.  If OEM-like points with a screw terminal can be found you may want consider going back to the correct 1962 setup.

Jeff Rosansky CLC #28373

May be worth checking the engine's ground.  Maybe run a dummy ground wire to the block and see if things get better.
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille