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Old 06-07-2013, 11:52 PM   #1
Steinerj56
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Problems starting when engine is warm

When I am trying to start my truck after driving for any period of time and the engine is warm it acts like the battery is dead and the engine barely turns over if at all for the first 5-10 seconds.

If I hold the key to the start position... knock on wood... it always starts but seems like it has a low or dead battery.

Got any solutions or ideas? could it by hydro locking when warm and shut off? fresh rebuild, 250 miles on engine rebuild.
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Old 06-07-2013, 11:57 PM   #2
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Re: Problems starting when engine is warm

Could be problem with a heat soaked starter.
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Old 06-07-2013, 11:59 PM   #3
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Re: Problems starting when engine is warm

Quote:
Originally Posted by Steinerj56 View Post
When I am trying to start my truck after driving for any period of time and the engine is warm it acts like the battery is dead and the engine barely turns over if at all for the first 5-10 seconds.

If I hold the key to the start position... knock on wood... it always starts but seems like it has a low or dead battery.

Got any solutions or ideas? could it by hydro locking when warm and shut off? fresh rebuild, 250 miles on engine rebuild.
Two things it could be, starter/solenoid heat soak or fuel boiling in the float bowl. Read through this thread:

http://67-72chevytrucks.com/vboard/s...d.php?t=570127

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Old 06-08-2013, 01:06 AM   #4
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Re: Problems starting when engine is warm

If its not turning over at all like you said, then its the starter getting too hot from the heat off the exhaust. Try rigging up a shield and wrap the exhaust near the starter with some of that header tape. I bet that fix it.
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Old 06-08-2013, 08:33 AM   #5
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Re: Problems starting when engine is warm

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Another solution for heat soak is to buy a smaller gear drive starter. That solved the problem on my White '67 with a 454.

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Old 06-08-2013, 09:10 AM   #6
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Re: Problems starting when engine is warm

I would verify starter, wires and terminals in good condition before heat shield mods unless exhaust is too close.
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Old 06-08-2013, 09:21 AM   #7
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Re: Problems starting when engine is warm

If all of the above fails to help, try and take a couple of degrees of timing out of it and see what happens. Too much timing will also cause this problem, especially when hot.
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Old 06-08-2013, 09:29 AM   #8
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Re: Problems starting when engine is warm

Then after everything else doesn't work, do this.
http://67-72chevytrucks.com/vboard/s...d.php?t=475748
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Old 06-08-2013, 10:23 AM   #9
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Re: Problems starting when engine is warm

hopefully will get a chance to look at it later today.

here is what I do know though if it helps you give me ideas on what to check.

same exhaust used that was there prior to rebuild and never had problem before. new intake, new carb, block bored out to 30 over, new lower end, new vortec heads. the starter has a Mr Gasket starter shield installed on it that was there prior.

let me know if you got any other ideas.
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Old 06-08-2013, 10:57 AM   #10
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Re: Problems starting when engine is warm

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Originally Posted by Steinerj56 View Post
hopefully will get a chance to look at it later today.

here is what I do know though if it helps you give me ideas on what to check.

same exhaust used that was there prior to rebuild and never had problem before. new intake, new carb, block bored out to 30 over, new lower end, new vortec heads. the starter has a Mr Gasket starter shield installed on it that was there prior.

let me know if you got any other ideas.
On a stock engine exhaust, never having had a problem before and with your symptoms my bet is either starter or battery. Worn starter bushings and the metal on the armature/windings swelling just enough to touch when hot will cause a dragging effect.

The battery may have enough juice when cold to start the engine but after heating up may be breaking down. Swap batteries first and then swap starter/solenoid as a complete asm.
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Old 06-08-2013, 12:07 PM   #11
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Re: Problems starting when engine is warm

While I was mowing, I remembered an engine my brother had rebuilt years ago. It was very tight. New everything and we suspected the ring gaps were on minimum side since he had the same problem after running for about 10-15 minutes or more. He overcame this by installing a new battery with higher cranking amperage but still tended to hesitate some so he retarded the timing some (someone mentioned that above). After several hundred miles it loosened up enough to crank properly.
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Old 06-08-2013, 12:19 PM   #12
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Re: Problems starting when engine is warm

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Originally Posted by 68gmsee View Post
While I was mowing, I remembered an engine my brother had rebuilt years ago. It was very tight. New everything and we suspected the ring gaps were on minimum side since he had the same problem after running for about 10-15 minutes or more. He overcame this by installing a new battery with higher cranking amperage but still tended to hesitate some so he retarded the timing some (someone mentioned that above). After several hundred miles it loosened up enough to crank properly.
That's a good point. Hope that's not the problem. On fresh carbed build I run 2 stroke fuel for a little insurance against fuel washed walls; call me crazy.
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Old 06-08-2013, 06:46 PM   #13
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Re: Problems starting when engine is warm

I had the same problem on my 72. Even if I drove a mile, shut it off, then tried to start it, it'd act like the battery was very low and you could hear the motor turning over VERY slowly. I replaced the starter, solenoid and installed a heat sheild, turns out it was just a bad ground wire though!! It didn't bother me though because now I have a new starter Check the grouds to your battery. It may be something simple like that, just like it was for mine.
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Old 06-08-2013, 06:58 PM   #14
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Re: Problems starting when engine is warm

Yes you guys are 100% correct. Check all your connections and ground first. Get a battery terminal cleaner brush and make sure everything is nice and clean. Just seems odd that it acts like the batter is dead when it's hot. That wouldn't be a fuel or timing issue. It's not even cranking over. Could also be a worn out battery as stated above. My money would be on the starter getting too hot though. I've seen it happen before. Check the voltage on the battery while cranking when it's cold and compare that to when it's hot.
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Old 06-08-2013, 07:40 PM   #15
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Re: Problems starting when engine is warm

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Originally Posted by TBONE1964 View Post
If all of the above fails to help, try and take a couple of degrees of timing out of it and see what happens. Too much timing will also cause this problem, especially when hot.
That's what I was thinking to.
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Old 06-08-2013, 08:43 PM   #16
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Re: Problems starting when engine is warm

I am timed right on 0 timing mark on the original mark. Is that correct?

I also will tell you I bought this truck a year ago and have the original battery it started with and it is a small battery. 550CCA it doesn't even come close to fitting the battery tray.

I was thinking about starting with a battery first and then going from there.

Not original exhaust. I do have headers that were on truck when I bought it.

Thanks for all the heads up and ideas where to look.
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Old 06-08-2013, 09:19 PM   #17
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Re: Problems starting when engine is warm

0 degrees advance is not correct. Not bad idea to do some timing googling.
0 degrees won't be your hard start issue though.
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Old 06-08-2013, 09:41 PM   #18
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Re: Problems starting when engine is warm

Timing and checking cleaness of connections is where I would start
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Old 06-08-2013, 09:43 PM   #19
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Re: Problems starting when engine is warm

Disconnect the vac adv from the dizzy and plug it (so no vac leak) Set the timing to around 12*btdc (pass side of tab i think).
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Old 06-08-2013, 10:00 PM   #20
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Re: Problems starting when engine is warm

Quote:
Originally Posted by asolde View Post
That's what I was thinking to.
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Old 06-08-2013, 11:50 PM   #21
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Re: Problems starting when engine is warm

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Originally Posted by Rufton View Post
0 degrees advance is not correct. Not bad idea to do some timing googling.
0 degrees won't be your hard start issue though.
ok so first restore and first engine rebuild.

reading spec sheet for Lunati Voodoo cam 10120701.

Says the above center line (108) will make this cam "4" advanced.
Lift on this cam is .454 in and .468 ex.

does this mean 4degrees advanced? or use an advance timing light and set it at 4 before setting it?
or like blue said 12 degrees btdc
sorry still learning, I appreciate all your advice.
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Old 06-09-2013, 01:28 AM   #22
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Re: Problems starting when engine is warm

Many street engines run well at 32 to 38 degrees all in advance.
You can normally measure all in advance with timing light when rev engine to approx 3000 rpm.
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Old 06-09-2013, 07:31 AM   #23
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Re: Problems starting when engine is warm

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Originally Posted by Steinerj56 View Post
ok so first restore and first engine rebuild.

reading spec sheet for Lunati Voodoo cam 10120701.

Says the above center line (108) will make this cam "4" advanced.
Lift on this cam is .454 in and .468 ex.

does this mean 4degrees advanced? or use an advance timing light and set it at 4 before setting it?
or like blue said 12 degrees btdc
sorry still learning, I appreciate all your advice.
It only means the valve timing is 4 degrees advanced. There is a difference between valve timing and ignition timing. When you set your timing with a timing light, ignition timing is what you are setting. The only way to change valve timing is by using a cam designed to do it or offset bushings in you cam gear.

"A little side note for you gear heads. If you install a stock small block Chevy crank gear on backwards, this will advance your valve timing 2 degrees." I am not sure if this is common knowledge so I thought I would share.

As you stated, with a timing light you have "0" degrees of ignition timing. That seems on the retarded side. You should have around 6 to 8 degrees with the vacuum advance disconnected.

You will have to play around with the ignition timing to get it the way you like it as far as performance. Not all engines like the same timing. My 72 shows my timing is to be set at 8 degrees but it runs better set at 10 and does not give me hard start issues when hot.

If you are at "0", it sounds like you may have a problem with heat soak on your starter like mentioned in prior post. I would still consider trying a different timing setting if nothing else works. You can always put it back to zero.

Last edited by TBONE1964; 06-09-2013 at 04:20 PM.
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Old 06-09-2013, 08:54 AM   #24
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Re: Problems starting when engine is warm

Warm engine.
Disconnect vacuum tube from vac advance.
Plug vac tube during test.
Make a note of idle timing (I think yours is 0 degrees now).
Watch timing change as rev engine.
Somewhere around 2000 to around 3000rpm you can observe engine reach max mechanical advance; many streeet V8 engines like 32 to 38.
Many engines are a ping risk above roughly 36.
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Old 06-10-2013, 11:11 PM   #25
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Re: Problems starting when engine is warm

ok guys I am irritated and I know how I get when I am irritated. I miss things.

****ty ground for sure for the battery. hopefully this gets rid of slow crank.

Bigger problem now. I set the timing to 10degrees BTDC. idle was great and sounded a lot better.

I took it out and drove it. ran well. pulled in drive way started backing into garage. filled the garage with white smoke and driveway with green fluid.

Now I have an engine that seems to be over heating. Cant find a specific leak but it looks like the radiator is shooting it out the over flow from the radiator which I don't have a hose hooked up to right now. Hit the exhaust and hot engine. Got any ideas why once its timed where it should be it would run hot and over heat? Sounded like fluid boiling in the drivers side of the engine. could have been in upper hose also.
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