slow cranking when hot

[1934]

My car starts normally when cold but turns over very slowly when I start it when it's hot. I have checked and cleaned the ground wire and all other connections. I've tried 3 different starters, (all of which bench-tested ok). Rebuilt coil from Skip, NOS condenser, good battery, etc. Any ideas what to try next?
Thanks, Doug.

[BW]

I was always told that timing will do this.

[swanwaco32]

Put a 8v volt battery in it..!!! Be sure to increase the voltage output of the generator to keep it charged. your lights and other functions can remain the same..

[tubman]

Originally Posted by swanwaco32

Put a 8v volt battery in it..!!! Be sure to increase the voltage output of the generator to keep it charged. your lights and other functions can remain the same..

Masking the symptom rather than curing the underlying problem is seldom a good idea. 8 volt batteries are for old worn out tractors that nobody wants to spend any time on, not prized collector autos. If you want to try a better battery, get an Optima. Otherwise it's connections, grounds, and cable size. One last thing; you do have the bracket that holds the back end of the starter up to the pan rail, don't you? I had to ask.

[rockfla]

after you check and have the bracket that holds the starter in line and positively in place make sure you have the correct size (Diameter) cables for both cables, a 6V system uses much larger battery cables than a 12V system. A quick way to make sure your cables are big enough is when cranking your car reach down and feel the positive side cable, if its hot by the time the car cranks, its too small of a cable. And the longer the positive cable, the bigger it needs to be. "Ought- O " diameter cable is the recommended starting size at least ,"00" is even better. Second would be the condenser, even though its a NOS one it could be failing when it gets hot....there have been "Several" post here on the barn on how to check your condenser and should be able to search that relatively quick and easy.

[RKS.PA]

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Did you recently rebuild your block?

[1934]

Thanks for the input, guys. I guess I'm missing something because I don't have any kind of bracket holding the back end of the starter??? There's just the 2 long bolts that hold the starter on. This is a '37 motor- was there supposed to be a bracket? Does this act as a ground as well?
I will try changing the condenser- I have several that are supposed to be NOS. The battery cables are new repros and supposed to be the right size.
Doug

[flatjack9]

As noted, feel the cables, ground cable also. If anything is hot, there's your problem. Could be a bad connection between the cable and cable end.

[tubman]

As far as I know, all flathead V8's had the bracket. Without it, the mass of the starter pulls it downward just enough to cock the starter which can cause a slight misalignment that could be your problem. The bracket is a simple "L"-shaped piece of steel with two (actually three; one is an oval shaped hole for lightening, I guess) holes in it. One of the long bolts passes through it, while the other "leg" is fastened by the appropriate oil pan attaching bolt. I'm sure they are available. You really should have one installed.

[rotorwrench]

The little starter support clips are available. It just bolts to one of the starter bolts and the other to the pan rail. I'm not as familiar with the old 21 stud set ups but most of the early fords I've come across have them. They were misplaced by previous owners a lot.

If your ignition distributor advance unit is sticking, it could be holding it advanced which could slow the start process. If you turn the starter with ignition off, it should turn normally since it can't try to kick back with the ignition off. If that test has no effect then something else has high resistance and is causing an excessive current draw. Checks for heat in the conductor cables have already been mentioned. A weak battery can get hot if the generator is working overtime trying to keep it charged.

[scicala]

Originally Posted by tubman

Masking the symptom rather than curing the underlying problem is seldom a good idea. 8 volt batteries are for old worn out tractors that nobody wants to spend any time on, not prized collector autos. If you want to try a better battery, get an Optima. Otherwise it's connections, grounds, and cable size. One last thing; you do have the bracket that holds the back end of the starter up to the pan rail, don't you? I had to ask.

Or ignition timing if the starter has been ruled out.


Sal

[B-O-B]

Reds Vintage Parts
Brace #81A-11140B or 8A-11140

[rockfla]

Originally Posted by tubman

As far as I know, all flathead V8's had the bracket. Without it, the mass of the starter pulls it downward just enough to cock the starter which can cause a slight misalignment that could be your problem. The bracket is a simple "L"-shaped piece of steel with two (actually three; one is an oval shaped hole for lightening, I guess) holes in it. One of the long bolts passes through it, while the other "leg" is fastened by the appropriate oil pan attaching bolt. I'm sure they are available. You really should have one installed.

Plus its one more point of ground (so to speak). I know one fellow with a 50 F1 had the same issue as you and he went through and grounded everything to everything and it sure cured his issue!!!`Motor to frame motor to body, motor to starter visa vie the anchor bracket etc etc.

[Shu47]

Why would timing affect how fast the starter turns over the engine? I understand how it could affect how quickly the engine fires up or if it will fire up at all but I don't understand how it will make the engine turn over slowly which is what I interpret the OP was asking about. I am not criticizing anybody's suggestion just trying to learn.

[rockfla]

Originally Posted by Shu47

Why would timing affect how fast the starter turns over the engine? I understand how it could affect how quickly the engine fires up or if it will fire up at all but I don't understand how it will make the engine turn over slowly which is what I interpret the OP was asking about. I am not criticizing anybody's suggestion just trying to learn.

SHu47 I'd like to learn too!!!

[petehoovie]

Originally Posted by tubman

As far as I know, all flathead V8's had the bracket. Without it, the mass of the starter pulls it downward just enough to cock the starter which can cause a slight misalignment that could be your problem. The bracket is a simple "L"-shaped piece of steel with two (actually three; one is an oval shaped hole for lightening, I guess) holes in it. One of the long bolts passes through it, while the other "leg" is fastened by the appropriate oil pan attaching bolt. I'm sure they are available. You really should have one installed.

Given the part numbers, I don't think the 'L' shaped starter support bracket 81A-11140-B and 8A-11140 was available prior to 1938.

FOR ALL 1938 MODELS FORD SPECIAL SHOP NOTES

STARTER SUPPORT BRACE:—To correct thump or
pound in engine when accelerated between 18 and
28 M.P.H., special starter motor to oil pan brace
82-A-11140-A1 (60 Engine), 81-A-11140 (85 Engine)
should be installed. Fasten this brace or bracket
to starter through-bolt at starter end, remove one
oil pan to cylinder block bolt and replace with
special bolt 20426-S (60 Engine), 20426-S2 (85 Engine)
to hold opposite end.

[flatjack9]

Originally Posted by tubman

As far as I know, all flathead V8's had the bracket. Without it, the mass of the starter pulls it downward just enough to cock the starter which can cause a slight misalignment that could be your problem. The bracket is a simple "L"-shaped piece of steel with two (actually three; one is an oval shaped hole for lightening, I guess) holes in it. One of the long bolts passes through it, while the other "leg" is fastened by the appropriate oil pan attaching bolt. I'm sure they are available. You really should have one installed.

I don't think that bracket was used until 37 or 38.

[1934]

I never considered timing as the culprit because the car runs well- never stalls or hesitates, lots of power, idles well and never over-heats. I'm thinking it might be the condenser. After doing a little research I realize that NOS ones can likely be defective due to age. In the morning I'll drive it around for a while, shut it off and then try cranking it over with the ignition off, (as suggested by rotorwrench).
Once again, many thanks.

[Tinker]

Starter gains most of it's ground from the face of the starter to the engine. No paint and clean is gooderest, a engine ground to frame doesn't hurt. But the Starter might need some attention, they dont spin like a modern vehicle ever on 6v ever. Mine sounds labored sometimes but always fires after a crank.

Timing would effect how fast it might fire. Model As had a manual advance on the steering column. Certainly started better with it retarded. You can check timing.

Get about 3 ih200 from napa, swap till ya find a good one.


.

[rockfla]

Originally Posted by 1934

I never considered timing as the culprit because the car runs well- never stalls or hesitates, lots of power, idles well and never over-heats. I'm thinking it might be the condenser. After doing a little research I realize that NOS ones can likely be defective due to age. In the morning I'll drive it around for a while, shut it off and then try cranking it over with the ignition off, (as suggested by rotorwrench).
Once again, many thanks.

If you go to the local NAPA for your condenser for a Bran Bran new one, do a little search here on the barn...Its been a subject well covered and just because they are new doesn't mean they are "good" or will last very long. I know in a previous post that NAPA part numbers & MFG markings were discussed as to how well they "Seem" to last (Also in V8 Times if I remember correctly and your are an EFV8 Club member), some better than others SO in summation you may want to invest in a couple of three of them and have one on stand by in the glove box for "just in case"!!

[RalphG]

If timing is advanced too much it will try to "kick back" the piston before it hits top dead centre. Making the starter hesitate every compression stroke. Also I remember six volt tractor starters that were fine cold but barely able to crank the engine when hot. We changed the starter and it made a huge difference. Some problem with the fields? Been too many years to recall but I know the changing the starter cured the hot start tractor problem.
And I don't recall seeing a starter brace to the pan rail on any of my flatheads. All crank over pretty good hot or cold.
And I don't see how the condensor can have any effect at all on cranking speed of the starter.

[Bored&Stroked]

I don't see how it could be timing or a condenser. The timing would be the same cold as hot . . . unless it somehow STUCK when it was hot and magically unstuck between when it was shutoff hot and then restarted when cold. (This is a possibility - but would seem to be a bit far fetched). Anything else related to the distributor would not be the cause of a slow-cranking issue.

Has the engine been recently rebuilt? If we've 100% ruled out the starter, battery cables and grounds, then one thought would be to use a torque wrench on the main crank bolt (up front) and see if the engine is a lot 'tighter' when hot. The torque readings can tell you this. Another thought is to pull the plugs when hot and see if it acts a lot differently.

Good luck and please report back.
D

[1934]

Up-date; This morning I started it and it seemed to turn slowly, even though it was a cold start. Went for a 15 mile drive, shut it off and tried cranking with the ign. off. It turned really slowly. After a lot of head scratching I decided to take all the wires off the starter switch. They looked clean and tight but I sanded them all nice and shiney and reinstalled them. After that it cranked over nice and fast! Had to go to work so didn't have much time to fool with it but maybe it wasn't a ground issue after all- just bad connections at the switch. Time will tell! BTW I found one of those starter brackets so plan to clean it up and install it.
Again,my thanks to all of you. Looking forward to a test drive tonight!
Doug.

[rockfla]

Originally Posted by 1934

Up-date; This morning I started it and it seemed to turn slowly, even though it was a cold start. Went for a 15 mile drive, shut it off and tried cranking with the ign. off. It turned really slowly. After a lot of head scratching I decided to take all the wires off the starter switch. They looked clean and tight but I sanded them all nice and shiney and reinstalled them. After that it cranked over nice and fast! Had to go to work so didn't have much time to fool with it but maybe it wasn't a ground issue after all- just bad connections at the switch. Time will tell! BTW I found one of those starter brackets so plan to clean it up and install it.
Again,my thanks to all of you. Looking forward to a test drive tonight!
Doug.

You might want to find a Saturday and go back through all of your grounds and starter switch connections and coat them with some form of corrosion inhibitor for electrical connections....There is a long running debate here on the barn about what is best....with that said I use Di-electric grease and has worked really well for me but whatever you land on will keep all those connections clean and fresh and working properly!!!

[1934]

Originally Posted by rockfla

You might want to find a Saturday and go back through all of your grounds and starter switch connections and coat them with some form of corrosion inhibitor for electrical connections....There is a long running debate here on the barn about what is best....with that said I use Di-electric grease and has worked really well for me but whatever you land on will keep all those connections clean and fresh and working properly!!!

Good advice, rockfla. That's what I'll do. Took the car out again tonight and the motor cranked over really fast! Shut it off when it was hot, left it for 5 min. and it turned over just as fast!
Doug.

[Tinker]

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Originally Posted by Bored&Stroked

I don't see how it could be timing or a condenser. The timing would be the same cold as hot . . . unless it somehow STUCK when it was hot and magically unstuck between when it was shutoff hot and then restarted when cold. (This is a possibility - but would seem to be a bit far fetched). Anything else related to the distributor would not be the cause of a slow-cranking issue.

Has the engine been recently rebuilt? If we've 100% ruled out the starter, battery cables and grounds, then one thought would be to use a torque wrench on the main crank bolt (up front) and see if the engine is a lot 'tighter' when hot. The torque readings can tell you this. Another thought is to pull the plugs when hot and see if it acts a lot differently.

Good luck and please report back.
D

I know you are completely correct. The point on ignition was if you crank for longer then you should and it doesn't fire, something is going on besides running your battery down. Timing etc....



Most electrical and "fuel" issues are just bad grounds. Don't quote me.

[Bored&Stroked]

Glad you figured it out and it was what typically tends to be the problem - just corroded connections that don't work well under high amp draws. I use dielectric grease if I'm having issues and/or the contacts are not well plated to prevent corrosion. Nothing like a nice wire brush and some grease to prevent future issues . . .

[joe 1950]

if ignition timing is to far advanced it will buck the starter make sure the timing is where it should be on your engine it should be at zero and vacum advance should be relaxed at idle

[Lawrie]

Another thing to cause this on our 33 was the starter switch itself, took it apart and cleaned up the contacts and that fixed it,.
Lawrie

[40ford]

I don't understand how a condenser would have anything to do with how fast the motors turns over?Timing might play a part in the problem.I would suggest you go to NAPA and have them make up new 00 gauge battery cables.I had the same problem and after changing cables I could not believe the difference!Here is the thread.If you solve your problem please let us know.So many of these threads are started with no end results!Just my 2 cents!


https://www.ford-trucks.com/forums/1...ad-solved.html

[1934]

40ford, this is actually an old thread but if you look at post #23 you'll see that I resolved the issue.
Thank you, Doug.

[40ford]

Ok,thanks Doug.I am glad you found what was causing the problem.

[JM 35 Sedan]

Reference a similar post for additional information by clicking on URL posted below .....

https://www.fordbarn.com/forum/showthread.php?t=278513