slow cranking when hot

[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