Slow Crank when Hot

[dmjlambert]

Yes, true if you have a plain wire supplying full 12V to the distributor, to replace the original resistor wire. What do both sides of your positive battery cable look like, and both sides of the negative battery cable? Can you post pictures? I misdiagnosed a starter problem because of a bad battery cable on my truck last year. Other people on the thread have talked about their headers, but didn't ask you if you have headers.

[71rehab]

Originally Posted by AussieinNC

Good old heat soak...

1/ Wrap the headers in heat wrap tape at least a foot in front of the starter and six inches behind the starter. Make it a double wrap thickness and secure it with hose clamps or wire.
2/ Replace the primary starter cable with a #2 cable, making sure it has totally clean connection ends.
3/ Replace the ground cable between engine block and battery ground, again, make sure contact surfaces are really clean.
4/ Check and clean all other ground cables making sure all connections are really clean.
5/ Double check battery charge rate is at least 14.2 volts at the battery itself with the engine running around 1500 rpm.
6/ Check static timing and set at 8 degrees at idle,,,idle being 650 to 700 rpm.
7/ If above fails, replace starter with small format reduction gear style starter that also has a heat shield built into its design.

Above all...have FUN !!!!

Hmmm my battery grounds to the alternator body. Then I have one more (very old and beat up) ground from the valve cover to the body. I have no frame to fender grounds.

And thanks for the recommendations!

[CC69Rat]

Does the truck have headers on it?

[71rehab]

Originally Posted by CC69Rat

Does the truck have headers on it?

No headers.

Also noticed that the starter has a NAPA sticker on it. So assume its a reman and that is probably the culprit? In any case, just ordered 5 new ground straps.

[71rehab]

Originally Posted by dmjlambert

Yes, true if you have a plain wire supplying full 12V to the distributor, to replace the original resistor wire. What do both sides of your positive battery cable look like, and both sides of the negative battery cable? Can you post pictures? I misdiagnosed a starter problem because of a bad battery cable on my truck last year. Other people on the thread have talked about their headers, but didn't ask you if you have headers.

Thanks. Cables are in great shape. Cleaned up the ends last night and still a tired starter after a drive.

[AussieinNC]

Yep, not needed when HEI equipped...but make sure its not able to short out anywhere...tape off the end with electrical tape and secure it away from heat sources like headers etc.

[AussieinNC]

Would suggest you replace the starter with a small format reduction style unit...new...not reman...

Grab a heat shield for it while you are ordering it...

Even without headers, the exhaust pipe will likely be putting too much heat onto older fat style starter...

Also...make sure there is a starter end support strap fitted and correctly in place...

GM part number is GM 23502557...most wholesalers carry them...even Amazon...

I have witnessed so many engine block damage scenarios with bolt holes stripped or broken out due to missing brackets...

[71rehab]

Originally Posted by AussieinNC

Would suggest you replace the starter with a small format reduction style unit...new...not reman...

Grab a heat shield for it while you are ordering it...

Even without headers, the exhaust pipe will likely be putting too much heat onto older fat style starter...

Also...make sure there is a starter end support strap fitted and correctly in place...

GM part number is GM 23502557...most wholesalers carry them...even Amazon...

I have witnessed so many engine block damage scenarios with bolt holes stripped or broken out due to missing brackets...

Something like this? http://www.jegs.com/i/JEGS-Performan...2/-1#reviewTab

[CC69Rat]

Just a little different perspective on it. If the truck is cold, it has a good battery charge / New battery and you drive it for a while.. It's hot, obviously and you shut it off. This is when you experience the sluggish starts. .. If the truck is hot when you try to start it back up.

If the truck sits for a few hours and cools completely off, will it start back up normally? .. or are you saying at that point, even cold it won't start back up until you charge / replace the battery?

[AussieinNC]

Yes Sir, that one will do fine...

on that Jegs page, also grab the heat wrap and the shim kit to correctly space pinion teeth from ring gear teeth.

Also...make sure you use the correct knurled shank bolts to attach the starter to the engine.

[dave`12]

Here is a link to my fight with this issue. I tried everything - long story short, nothing fixed it until I got a high torque mini starter.

http://67-72chevytrucks.com/vboard/s...d.php?t=729029

[landarts]

Had exactly the same problem you are having and did this to correct it. http://67-72chevytrucks.com/vboard/s...d.php?t=363603

[richards72chevy]

My truck had the same issue ended up putting a thicker gasket in between the carb and manifold and the problem went away.This is a common problem just on the edelbrocks.

[Grumpy old man]

Post a pic of your engine ,

Does it look like this http://67-72chevytrucks.com/vboard/s...d.php?t=509243

or this http://67-72chevytrucks.com/vboard/s...d.php?t=457938

It all makes a difference , next time you have a hard to crank issue use a set of jumper cables and hook them directly to the starter + post and a solid ground - next to the starter , get in turn the key and if it starts fine its your battery cables/ connections , If it still starts hard it's your starter is suffering heat sink . you can't ground your system to a valve cover . why jump to parts suppliers like jegs when anyone of your local auto parts stores carry exactly what you need just down the street ? personally I'd just go buy a new mini starter and a new set of good battery cables and be done with it ,

So many get hooked on setting up their 50 year old truck by the numbers the book say 8 degrees timing BUT it just may run better at 6 or 10 . these aren't computer driven systems . It's called tuning for a reason ...

[franken]

I'd put the big ground cable directly on the block, not the alternator bracket.
What exactly is the voltage across the battery with the engine off and running?
How many CCA is the battery rated at?
I'd also be looking at the positive and negative cables and make sure they're in good shape. Grumpy's suggestion with the jumper cables is good, but the wording is a little funny. Connect from the + battery terminal to the big cable connector on the starter, then crank. Similarly, connect to the - terminal and to the starter body, then crank.

[71rehab]

Originally Posted by Grumpy old man

Post a pic of your engine ,

Does it look like this http://67-72chevytrucks.com/vboard/s...d.php?t=509243

or this http://67-72chevytrucks.com/vboard/s...d.php?t=457938

It all makes a difference , next time you have a hard to crank issue use a set of jumper cables and hook them directly to the starter + post and a solid ground - next to the starter , get in turn the key and if it starts fine its your battery cables/ connections , If it still starts hard it's your starter is suffering heat sink . you can't ground your system to a valve cover . why jump to parts suppliers like jegs when anyone of your local auto parts stores carry exactly what you need just down the street ? personally I'd just go buy a new mini starter and a new set of good battery cables and be done with it ,

So many get hooked on setting up their 50 year old truck by the numbers the book say 8 degrees timing BUT it just may run better at 6 or 10 . these aren't computer driven systems . It's called tuning for a reason ...

1. Engine bay is dirty and original aside from HEI..

2. Battery cables are like new.

3. Starter is a reman from Napa.

4. After replacing all of the ground straps and adding some more, I still have the same issue. Easy crank when cold. SLow crank when warm. I will try the jumper cable test.

5. Your point on timing is noted. In the past, I've noticed when it is advanced too much it doesn't turn as freely.

[57Suburb]

You've already had several tell you the same thing already, but I had exactly the same problem, went through all the same steps to make sure it wasn't something simple, and ended up purchasing and installing one of these. Starter from a 98 Tahoe. Problem solved.

[71rehab]

Originally Posted by 57Suburb

You've already had several tell you the same thing already, but I had exactly the same problem, went through all the same steps to make sure it wasn't something simple, and ended up purchasing and installing one of these. Starter from a 98 Tahoe. Problem solved.

thanks. ive seen at least a dozen starter recommendations from reman to mini to Corvette.