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Sure sounds like heat sink in the solenoid. Direct to starter power when hot would tell you for sure. If so, new solenoid or remote mounting of solenoid
Originally Posted by ehrhartc
Fresh build on the 454 with 9.5 compression.
I have replaced all 3 battery cables - positive to starter, negative to frame, block to frame.
I have also added a 3rd ground from the starter bolt to the frame.
I have replaced the starter (reman Delco) and the battery (650 CCA)
Put a charger on the battery to make sure I had it fully charged.
I have added a remote solenoid mounted on the firewall.
I scraped the frame clean at the battery and the engine mount.
I have checked to ensure all connections are tight.
The starter has the stock heat shield between the solenoid and the stock exhaust manifold.
When cold it starts up quickly.
When hot - the starter will barely turn over and I can hear a noise coming from the remote solenoid.
After a few hours of cool down - it starts just fine.
I know there are a hundred posts on this subject and that is where I picked up the idea of the remote solenoid.
I am stumped.
Is there electrical testing I can conduct to check voltage, resistance, etc ??
I am sure grounds are good - I have filed the bolt point on the frame point and have run 2 grounds cables - 1 from the block (stock) and added the 2nd one from a starter mounting bolt to the frame.
I have already installed the remote solenoid on the firewall. But as I consider the function - it still requires the solenoid on the starter to push the gear into position to turn the flywheel. - makes me wonder if the remote solenoid really does much to correct heat sink.
Assuming originality is not a big concern, get a modern gear reduction starter and be done with it. I installed one out of a '96 full size truck and haven't had a problem since.
Before you go, spending a lot of money figure out what the problem is first, get one of these at Harbor freight it’ll test the battery and the starter! Your solenoid is clicking because it’s making a contact and then breaking the contact the disc in there is dirty take it apart and clean it with a wire brush, there’s two flimsy wires in their Made of silver you’ll break them easy
I have already installed the remote solenoid on the firewall. But as I consider the function - it still requires the solenoid on the starter to push the gear into position to turn the flywheel. - makes me wonder if the remote solenoid really does much to correct heat sink.
It should - but how much?
Resistance is directly proportional to temperature - whenever temperature increases- the resistance of the conductor will also increase.
Rule of thumb- run one GA wire LARGER ( down in GA) underhood.
I'm running 00 (2/0)
I am running 12.25-1 Compression in my 1968 C3 BB Convertible and I spent a lot of time finally getting a reliable starting car that I can trust. Between the high compression and Long tube headers they would both cook my starter. The car had to cool down for a while before it would crank even with a GM Performance Starter.
For me the solution was simple, I bought a Gear Drive Starter capable of much higher compression than I use. This alone would start the engine even when hot. Then to really make things work great I put a MSD Ignition that would retard the ignition by up to 20* ONLY while cranking and then returning to normal timing after you reach 400 r.p.m. This unloads the starter in a Big way and with the Gear Drive Starter and the timing retard box together my 12.25-1 makes my 427 crank like a Slant Six, it starts up very quickly.
There are several ways to do it, even the Holley Sniper Series EFI systems have the ability to pull timing while cranking There are several devices that can pull the timing. Between the gear drive starter and retarding timing the starting issues on my Corvette are GONE.
Yup, start retard makes life easy. Also helps prevent broken starter snouts. I have my FAST XFI set to retard the timing under 600 (if I remember correctly) RPM.
And after breaking multiple GM and Powermaster starters, I bought a Tilton. Buy once, cry once.
My all stock 73 big block had the exact issue since the day I purchased it 7 years ago.
Turned out my issue had nothing to do with the battery, cables, wiring or the starter.
My issue was vapor lock.
The starter spun fine and the engine started without hesitation cold, but after driving for a while, if I shut it off to get gas or lunch, the starter would drag and it took everything it had to start.
After it did start it would run rough for a few minutes until cool fuel and air filled the carb.
Setting the timing pursuant to Lars timing papers helped, connecting the fuel return line, adding a phenolic carb spacer, blocking off the heat riser ports between the heads and intake and rerouting the fuel line from the pump to the carb seemed to solve the problem.
I was really shocked at how much heat gets trapped under the hood of my 73 big block and your 74 isn’t any different.
Let us know what you find!
Correct. The solenoids are pretty cheap to replace. Then I'd use an insulating blanket for it as well.
Originally Posted by ehrhartc
I have already installed the remote solenoid on the firewall. But as I consider the function - it still requires the solenoid on the starter to push the gear into position to turn the flywheel. - makes me wonder if the remote solenoid really does much to correct heat sink.
I'd not think vapor lock would cause any diminution in the cranking ability of the starter as the addition or withdrawal of fuel vapor does nothing to the compression ratio.
The heat causinbg the vapor lock would/could.
Vapor lock is heat related and your numerous fixes there certainly fixed the VL problem and may have ancillarily reduced the heat soak on the starter and solenoid.
Originally Posted by OldCarBum
My all stock 73 big block had the exact issue since the day I purchased it 7 years ago.
Turned out my issue had nothing to do with the battery, cables, wiring or the starter.
My issue was vapor lock.
The starter spun fine and the engine started without hesitation cold, but after driving for a while, if I shut it off to get gas or lunch, the starter would drag and it took everything it had to start.
After it did start it would run rough for a few minutes until cool fuel and air filled the carb.
Setting the timing pursuant to Lars timing papers helped, connecting the fuel return line, adding a phenolic carb spacer, blocking off the heat riser ports between the heads and intake and rerouting the fuel line from the pump to the carb seemed to solve the problem.
I was really shocked at how much heat gets trapped under the hood of my 73 big block and your 74 isn’t any different.
Let us know what you find!
I purchased the load tester that DOGMARK recommended at Harbor Freight and tested the battery, starter and charging system as outlined in the instruction sheet.
The battery showed 12.6 at rest. when I toggled to "load" it remained in the "green range" for a 650 CCA battery. When I tested the charging system at fast idle - the system showed "green" at 14.1.
I have also added a heat wrap around the starter in addition to the stock shielding.
I also ran a new (additional) purple wire from the seat belt interlock under the console to the S terminal for the starter (the old wire is still in place)
Then I drove the car - got it to operating temperature and turned it off to perform the starter load test.
With the load tester connected to the battery, I turned the key to start - the starter barely turned over and the gauge went Red (bad) at between 8-9 volts on the hot engine.
Now I am thinking of adding an additional positive cable 2/0 AWG to the other new 2/0 AWG - thinking that it might "mirror" the 0/0 old original cable I replaced.
I don't think an additional power wire will solve a possible solenoid heat soak problem. As I mentioned, before going through the process of hard wiring another copper line. With the car fully supported and chocked, just run a good sized jumper cable from the battery directly to the starter, bypassing the solenoid, and check for symptoms. That will tell you if it's the power lead or the solenoid. (or poor connections) While you said it starts fine cold, I usually run the max CCA I can find for a given size battery and wouldn't run less than a 750 CCA in my 6 cylinders let alone my relatively high compression C3.
Keep us posted.
Originally Posted by ehrhartc
I purchased the load tester that DOGMARK recommended at Harbor Freight and tested the battery, starter and charging system as outlined in the instruction sheet.
The battery showed 12.6 at rest. when I toggled to "load" it remained in the "green range" for a 650 CCA battery. When I tested the charging system at fast idle - the system showed "green" at 14.1.
I have also added a heat wrap around the starter in addition to the stock shielding.
I also ran a new (additional) purple wire from the seat belt interlock under the console to the S terminal for the starter (the old wire is still in place)
Then I drove the car - got it to operating temperature and turned it off to perform the starter load test.
With the load tester connected to the battery, I turned the key to start - the starter barely turned over and the gauge went Red (bad) at between 8-9 volts on the hot engine.
Now I am thinking of adding an additional positive cable 2/0 AWG to the other new 2/0 AWG - thinking that it might "mirror" the 0/0 old original cable I replaced.
My hot engine starter issue was fixed by adjusting the timing. Worked fine cold, but hot would act like it could barely find enough umph to turn the engine over. New battery was fully charged and battery wires recently replaced. Did not have any noise from the solenoid. I forget if I advanced or retarded but it was just a few degrees. Works fine now.
Just a closing epilogue to the hot start problem.
Someone in the Forum suggested a PMGR starter for a 1999 GM 3500 7.4L truck engine.
I purchased one from Rock Auto - new AC Delco for $107.00. It is a direct fit for the engine, however, it is shorter, so I could not use the stock nose to block brace. With a weight of 8 lbs as opposed to the OEM 19 lbs, it's not an issue.
I did have to buy 4 1/2 inch grade 8 bolts to install it.
THE PROBLEM IS SOLVED...!!!
Both my 74 and my uncles 76 had this same issue... In the end it was poor wiring connections that was the cause on both cars. On mine it was fixed by replacing the terminal end on the ground wire where it attaches to the car chassis. on my uncles, it ended up being a combo of a weak "new" battery and also a poor ground connection. My uncle swore up and down it was a new battery and it was fine... He even replaced the starter when troubleshooting.
I fought that problem for years with my car. Turned out the post on the alternator, under the rubber cover, was severely corroded. When I tried to unhook the wires to clean it off, it broke. Replaced the alternator, problem solved.
01-30-2024, 02:13 PM
