Starting Troubleshoot - Heatsoak?

[Jferrante]

Hey everyone - need some insights. My 64 is having starting issues after the initial startup- for example I am starting the car in the garage let it run and then it has trouble firing up again after getting hot. I just installed the heat insulator for the starter and also wrapped the headers with insulation wrap - same problem. Car barely turns over. Let her sit for 5 mins and fires up, turn it immediately off and try again but trouble starting.

As a reference, the car is freshly rewired, new battery, leads and new ground.
If this was a heat soak issue shouldn't I be good after the double insulation?
Before buying a new starter I want to confirm here.
Thanks

[Tazimafied]

This is something common in high performance engines that have high compression and advanced timing. I would check the timing first to make sure it isn't too far advanced for your setup. If it is where you want it to achieve the desired performance then I would check the starter next. It could be just old and weak enough to not be able to turn the engine over when hot. If the starter is fairly new I would recommend upgrading to a higher performance unit.

[The Rocknrod]

And or install a Starter Relay.

[Jferrante]

Originally Posted by Tazimafied

This is something common in high performance engines that have high compression and advanced timing. I would check the timing first to make sure it isn't too far advanced for your setup. If it is where you want it to achieve the desired performance then I would check the starter next. It could be just old and weak enough to not be able to turn the engine over when hot. If the starter is fairly new I would recommend upgrading to a higher performance unit.

Thanks. ..might just bite the bullet and get a new unit as I don't know how old this one is. It iseems no longer produced but most likely is a rebuilt unit. If the new starter doesn't do it ill make sure to refer back to the timing.

Originally Posted by The Rocknrod

And or install a Starter Relay.

Thanks I read this as the other option as well but was hoping I didn't have to.

[Jferrante]

Bought a new high torque starter and installed it tonight - that thing spins it quick. Still getting hesitation after letting run a little but it seems the extra oompf in the new starter is what it needs to crank over. I think its a voltage problem as the starter seems to be spinning fine.
I did a quick check on battery voltage. Brand new battery 2 months ago and reading 12 -12.1 volts after running (should be higher)...13.5ish while on (seems right). I may need to charge the battery since the car does sit for days on end but it seems that isn't helping.
Thanks for the help.

[T and S]

Go to MADelectrical.com and read about heat causing starting problems before you throw a lot of money at it. You might be able to fix it for just a few dollars and a little elbow grease.

[franken]

Originally Posted by The Rocknrod

And or install a Starter Relay.

Don't. This would label the OP as clueless. Adding an other solenoid is like duck taping a new leg toy yours when it gets sore. The old one is still there doing tha same job it always has.

Slow crank is internal solenoid contacts switching the starter on/off, or the big battery cables bad, resistive connections on same, grounding something other than the block, dead battery, or a starter problem. Note how few problems are the solenoid. All cranking current flows through the big cables. Rarely, the starter is bad.

If the solenoid makes no noise or clicks trace the circuit from the battery + terminal, small red wire all the way to the solenoid S-terminal purple wire.

Get a long piece of #12 stranded wire and put 2 alligator clips on the ends. When the problem occurs, test. Connect one end to the solenoid S-terminal. Put the truck in park or neutral. Touch the other end to the battery + terminal. Any change?

A charged battery is 12.6V with a small load. Anything less, even 12.5 is in need of a charge.

[Jferrante]

Originally Posted by T and S

Go to MADelectrical.com and read about heat causing starting problems before you throw a lot of money at it. You might be able to fix it for just a few dollars and a little elbow grease.

Thanks - starter seems to have been discontinued and since I replaced the full wiring, battery and cables I figured why not just do the starter now and not have to worry about it. Newer truck for me so I like knowing parts are fresh.

Originally Posted by franken

Don't. This would label the OP as clueless.

Slow crank is internal solenoid contacts switching the starter on/off, or the big battery cables bad, resistive connections on same, grounding something other than the block, dead battery, or a starter problem. Note how few problems are the solenoid. All cranking current flows through the big cables. Rarely, the starter is bad.

If the solenoid makes no noise or clicks trace the circuit from the battery + terminal, small red wire all the way to the solenoid S-terminal purple wire.

Get a long piece of #12 stranded wire and put 2 alligator clips on the ends. When the problem occurs, test. Connect one end to the solenoid S-terminal. Put the truck in park or neutral. Touch the other end to the battery + terminal. Any change?

A charged battery is 12.6V with a small load. Anything less, even 12.5 is in need of a charge.

Thanks seems you know this stuff pretty well - the new starter is moving so it looks like the low battery is now the main culprit on the slow starts. Will charge and report back to everyone.

[franken]

Originally Posted by Jferrante

Bought a new high torque starter and installed it tonight - that thing spins it quick. Still getting hesitation after letting run a little but it seems the extra oompf in the new starter is what it needs to crank over. I think its a voltage problem as the starter seems to be spinning fine.
I did a quick check on battery voltage. Brand new battery 2 months ago and reading 12 -12.1 volts after running (should be higher)...13.5ish while on (seems right). I may need to charge the battery since the car does sit for days on end but it seems that isn't helping.
Thanks for the help.

You need to charge the battery disconnected on the - side from the truck for a few days, assuming a slow charge. That voltage reading is very low, and if the truck only sits for a few days is too low. After charging and running it, I'd disconnect the - battery cable each time after use and see if the trouble goes away.

If it does, you're looking at something discharging the battery when the vehicle isn't in use.

[Jferrante]

Originally Posted by franken

You need to charge the battery disconnected on the - side from the truck for a few days, assuming a slow charge. That voltage reading is very low, and if the truck only sits for a few days is too low. After charging and running it, I'd disconnect the - battery cable each time after use and see if the trouble goes away.

If it does, you're looking at something discharging the battery when the vehicle isn't in use.

Yup these were my next thoughts. New AAW wiring harness so I thought there might be a draw from something I didnt hook up.

[franken]

Originally Posted by Jferrante

Bought a new high torque starter and installed it tonight - that thing spins it quick. Still getting hesitation after letting run a little but it seems the extra oompf in the new starter is what it needs to crank over. I think its a voltage problem as the starter seems to be spinning fine.
I did a quick check on battery voltage. Brand new battery 2 months ago and reading 12 -12.1 volts after running (should be higher)...13.5ish while on (seems right). I may need to charge the battery since the car does sit for days on end but it seems that isn't helping.
Thanks for the help.

You need to charge the battery disconnected on the - side from the truck for a few days, assuming a slow charge. That voltage reading is very low, and if the truck only sits for a few days is too low. After charging and running it, I'd disconnect the - battery cable each time after use and see if the trouble goes away.

If it does, you're looking at something discharging the battery when the vehicle isn't in use.

[Jferrante]

Originally Posted by franken

If it does, you're looking at something discharging the battery when the vehicle isn't in use.

Definitely parasitic draw causing this - went home today to check and battery down to 4 volts ...

I realized I have the small battery wire running to a headlight relay mount that isnt being used. Think this is it....shall see tonight.

[The Rocknrod]

Originally Posted by T and S

Go to MADelectrical.com and read about heat causing starting problems before you throw a lot of money at it. You might be able to fix it for just a few dollars and a little elbow grease.

From their web site:
http://madelectrical.com/catalog/st-1.shtml
"GM HOT START PROBLEMS
There are two independent categories of hot start problems with the GM DELCO built starting system.

(1) Nothing happens when the key is turned to "START"–although the headlights will burn brightly, and the rest of the electrical system is fine. The problem most often occurs in hot weather, and with the engine warmed up, after about a ten-minute stop. (Heat increases resistance at wiring and electrical parts.)

This is the type of problem, which will be cured with installation of the START'M UP kit. The problem occurs because the large solenoid on the GM starter draws 40 to 50 amps at the moment the key is turned to "START." And that large amount of current must flow through a very lengthy circuit, from the battery to the dash area. Through dash wiring and switches, back out through the under-hood wiring, finally to the starter.

The START'M UP kit will reduce current flow through the lengthy circuit to only 2 amps–then the system will work fine.
(2) SLOW CRANKING, a gr-r-runt, gr-r-runt. This kit won't fix it! You'll need to work with ignition timing, battery cables, the starter, and the rest of the system."

[T and S]

I plan on doing the starter relay in mine - I don't care what people think. If they don't like it - don't look at it

[Turtleman]

What gauge wire goes from the started solenoid to the ignition switch?

I had the same issues.. everything works fine until I get up to running temperatures then once its shut off I cant turn the starter over until it cools down..
Seems a common issue with these when a V8 goes in with a set of headers.. the space between the starter and header is very close so when it gets warm the copper wiring in the solenoid expands to the point that the OEM 14 gauge cant carry the amps to turn the starter over.
I replaced the wire from the solenoid to the first junction at the firewall with a 10 gauge wire and have never had any start issues since

[Jferrante]

Originally Posted by Turtleman

What gauge wire goes from the started solenoid to the ignition switch?

I had the same issues.. everything works fine until I get up to running temperatures then once its shut off I cant turn the starter over until it cools down..
Seems a common issue with these when a V8 goes in with a set of headers.. the space between the starter and header is very close so when it gets warm the copper wiring in the solenoid expands to the point that the OEM 14 gauge cant carry the amps to turn the starter over.
I replaced the wire from the solenoid to the first junction at the firewall with a 10 gauge wire and have never had any start issues since

You might better getting at something. Since I have a 350 with headers....the wire gauge is the gauge from the AAW kit. I am guessing you are referring to the purple wire? If so I'm not sure the gauge off the top of my head. Someone should be able to chime in tho.

[Turtleman]

Thats the small wire that goes from the terminal post on the solenoid (purple) its 14 gauge.. replace that with a 12 or 10 gauge,, (I did 10 because I'm weird that way).

Run the truck until it gets hot and see if your amp drop is resolved.. the 14 gauge wire has just the right amount of amp drop so it wont kick the solenoid once the wires in the solenoid expand...

After I did this I've never had to deal with a hot start again.. and I live in a HOT area.