[red_bumblebee]

Hi all,

Thanks for the replies, I've made a list of everything I'm going to try, starting with better grounds from battery to somewhere else on the head and a better ground for the starter.

If it helps with diagnosing online, when it gets hot it will very slowly turn the starter, making a RR ......................RR......................RR and then sometimes it won't crank anymore at all (that was with the old battery, I haven't tried to crank it for a long time when it's been hot with the new battery yet.)

I used one of those mini battery pack jump starter things once and it seemed to crank more easily, but it still cranked very slowly. It did sound like the battery was dead. I let it cool down and then with the batter jump pack it cranked like a good battery.

Initial idle timing looked to be around 6 degrees or less when I checked the other day.

I'll check the ignition switch as well but the backdrive linkages have been removed and the lockout switch is now with a B&M shifter. The ignition switches a relay which powers the solenoid so I would think that it ok, but I'll check the original solenoid wire as it is 43 years old and has multiple connections in it where its been cut and spliced previously.

[gtofreek]

Originally Posted by red_bumblebee

Hi all,

Thanks for the replies, I've made a list of everything I'm going to try, starting with better grounds from battery to somewhere else on the head and a better ground for the starter.

If it helps with diagnosing online, when it gets hot it will very slowly turn the starter, making a RR ......................RR......................RR and then sometimes it won't crank anymore at all (that was with the old battery, I haven't tried to crank it for a long time when it's been hot with the new battery yet.)

I used one of those mini battery pack jump starter things once and it seemed to crank more easily, but it still cranked very slowly. It did sound like the battery was dead. I let it cool down and then with the batter jump pack it cranked like a good battery.

Initial idle timing looked to be around 6 degrees or less when I checked the other day.

I'll check the ignition switch as well but the backdrive linkages have been removed and the lockout switch is now with a B&M shifter. The ignition switches a relay which powers the solenoid so I would think that it ok, but I'll check the original solenoid wire as it is 43 years old and has multiple connections in it where its been cut and spliced previously.

If the starter is cranking, or trying to crank, the ignition switch is working, so it's not that.
Grounds on the exhaust get worse with heat. That's why I suggested a voltage drop test. That will tell everything. To test the positive cable, you just do the opposite of what I explained for the negative cable. Hook the positive lead from the volt meter to the positive post of the battery, and the negative lead to the other end of the cable at the starter. Disconnect the coil wire, and crank the engine and see if the meter reads anything. A good cable will read no voltage during this test. Any voltage reading over .3 volts and the cable or connection is bad. Connections get worse with heat also, especially when they are not good connections in the first place. They build heat from within as they are being used.

I specialized in auto electrical, especially starting and charging systems, here in the Arizona desert for over 11 years before I started doing engine work. Believe me heat soak is not uncommon around here, but a properly working, stock starting system will still turn over an engine just fine when it's heat soaked. If they wouldn't, GM never would have installed them on these cars in the first place. My 428 had high compression, and headers that wrapped right around the starter. I never had cranking issues with it in the heat of the summer.