Author Topic: 62 Hard to start  (Read 1500 times)

Offline Lexi

Re: 62 Hard to start
« Reply #10 on: December 26, 2017, 09:34:57 AM »
I added an electric fuel pump to my '56. Fairly good start up now. You could also try a one way valve to prevent gas from leaking back from carb, though residual engine heat probably boils off a lot of the carb fuel so this may only provide some assistance. Clay/Lexi

Offline Roger Zimmermann

Re: 62 Hard to start
« Reply #11 on: December 26, 2017, 10:02:32 AM »
As the fuel inlet at the cab is higher than the fuel level, how do you explain th<t the fuel is leaking back from the carb?
The carbs from that time are vented to the atmosphere; due to the engine heat, it just evaporates. After 24 hours, there is still enough fuel in the carb for to start the engine without problem. However, this phenomenon continues with a cold engine and, after 2 or 3 days, the remaining fuel is not sufficient to start the engine.

Offline Lexi

Re: 62 Hard to start
« Reply #12 on: December 26, 2017, 04:19:47 PM »
Yes Roger is correct, the inlet is indeed higher and the 2 vent stacks in the '56 carb I imagine would further nullify any chance of a reverse fuel flow as it is not a closed system. I had been told that these inline valves do help, but as was more clearly indicated they would not address the main problem. That is because they would only keep what fuel is left in the line after the valve, (rather than impacting what is in the bowl). So their effect would be marginal and short lived. Like Roger, I always thought that residual engine heat and evaporation through the stacks was the main culprit. So after a few days the problem will still be there. That is why I installed an electric pump on a by-pass line.

Russ also complained; "Once it is warm it doesn't want to turn over good". Timing was noted as a possible cause. Certainly a possibility and easy to check. I did have that problem also, and it came down to the starter motor not running as efficiently when hot, resulting in a slower or a hesitant crank. Some after-market solutions involved the installation of heat shields for the starter motor as well as some type of insulating material wrap as an alternative method to keep resistance inducing engine heat away from the starter motor. I had mine rebuilt and then serviced twice afterwards to be sure it was OK. I was told that it was a fact of life with many of these older units that heat can cause them to operate not as efficiently. Perhaps a member has used a heat shield or wrap and can comment on whether they helped? Clay/Lexi

Offline walt c

Re: 62 Hard to start
« Reply #13 on: December 26, 2017, 09:30:31 PM »
Quote
By now you've probably solved your cold "hard to start" problem, but, if you haven't read on. My original 1955 CDV  with Rochester 4GC (I rebuilt this carb before I even bought the car!) was hard starting when cold if the car sat more then 48hrs or so. I also have a professionally rebuilt 4GC that I installed and ran briefly to ensure it would be a roadworthy replacement should I ever need it for troubleshooting purposes. It was also "hard to start" after sitting a couple of days. After living with this forever (18yrs or so!) I got serious and began to adjust the choke closing closer to zero vs the factory adjustment which was closer to .040 I believe. (don't feel like pulling my service manual at the moment to confirm that setting) Well, after adjusting the choke plate closer to zero the motor starts VERY GOOD now even if the car sits for a week! (very good, not GREAT like my son's 64 Chevelle with an inline motor)(you can't release the key fast enough when cranking to start it....it fires that fast!) This has been my experience with cold starts on Cadillac with a 4GC carb....walt...tulsa,ok.......      I did open my manual today and the correct choke rod adjustment is .040. Mine was set at .038 and thus I adjusted it closer to .000 and the starts are MUCH better now.....hope this help someone. I'm surprised John Washburn hasn't chimed in. Living in Colorado at altitude and cold temps surely he has knowledge on choke settings....walt...tulsa,ok 

Offline Roger Zimmermann

Re: 62 Hard to start
« Reply #14 on: December 27, 2017, 02:46:23 AM »
I was told that it was a fact of life with many of these older units that heat can cause them to operate not as efficiently. Perhaps a member has used a heat shield or wrap and can comment on whether they helped?
On my 3 cars, I never had that problem. The only work I did on the starter motors was to replace the solenoid and the pinion/clutch assembly.

Offline Lexi

Re: 62 Hard to start
« Reply #15 on: December 27, 2017, 11:40:46 AM »
I experienced that problem with two of my '56s, though after chatting with some car guy buddies at a local cruise night, it was not just Cadillac starters that were affected. My buddies '55 Chevy had the same issue, until he installed a heat shield. He said it was a problem for GM cars of this era, (not sure about other makes). Clay/Lexi

Offline russ austin

Re: 62 Hard to start
« Reply #16 on: December 27, 2017, 11:54:24 AM »
My fix for the slow crank on a hot engine was a new battery cable. Corrosion had gotten past the insulation and into the wire strands.
63 series 62 4 window sedan, 63 Superior Hearse
62 Fleetwood

Tucson, AZ  USA

Offline kkarrer

Re: 62 Hard to start
« Reply #17 on: December 27, 2017, 09:07:58 PM »
I just want to add a bit to the conversation.  I've experienced this issue with several Cadillacs (and other makes, especially Ford Y block cars) and have done the following to resolve the problem.  (this is after proper carb rebuilding. timing, dwell, and automatic choke checks).  First, I install a phenolic resin insulator between the carb and the intake manifold. These are available on the internet.  This provides some insulation to help with the aforementioned "heat sink" problem and also provides a little more space for the fuel/air mix to be aspirated or vaporized.  Next, in all but one of my restorations, I install a Pertronix ignition module.  I know some of you guys hate them, but I never have a problem with them and they help to cut a lot of time from trouble shooting points and condensers.  After that I install a 12v low pressure electric fuel pump on the rail or as near to the gas tank as possible and install a micro-switch under the roll of the dash (there are usually several holes there already for mounting purposes).  The purpose of the electric fuel pump is to provide fuel to the carb after a few days or weeks of sitting idle (aids cold starts and saves your battery and starter). Turning the electric pump on for about 10 seconds prior to starting works well.  The purpose of the ancillary pump is not to run the car for long periods of time, unless the mechanical fuel pump fails.  However, in some very hot regions of the country (Austin, Texas being one), if, due to the alcohol in the fuel, the car starts to lose power due to vapor lock, I hit the electric pump to force fuel to the carb and run with the pump engaged for a few minutes until things smooth out. I then turn the electric pump off and let the mechanical pump do its job.  I've also experimented with rerouting fuel lines (away from the manifolds) and making temporary (in the case of show cars) heat shields.  So far none of my pump  and switch set ups have caused any deduction for show points, but they have produced lots of quick starts and peace of mind for happy motoring and greater likely hood that the car will be driven.
Ken Karrer
CenTex Reg. Dir.

Offline Lexi

Re: 62 Hard to start
« Reply #18 on: December 28, 2017, 12:42:37 AM »
Good advice from Russ as that would account for some of these issues. Sometimes you can't see the rot but once removed and examined, green corrosion that was hidden inside just pours out. I had replaced mine with a heavier gauge cable just in case but my problem remained. Clay/Lexi