Drag on hot starts

[Adam1971]

Hey folks, need a little help with a small problem. I have a ‘71 c10 with a 350, Hei ignition, and aftermarket fuel injection. When I park it and come back to it within about 5 to 10 mins the starter seems to drag, and then it will crank. I’ve had the starter tested and it’s good. If I wait until the motor has cooled more it starts fine. Any ideas would be appreciated!

[garyd1961]

Either heat soak on your starter or your timing is a little high. Do you have headers if so that will cause heat soak. What type starter are you running? A mini starter might help.

[Grumpy old man]

Put a starter heat shield on it .

https://www.summitracing.com/parts/t...SABEgJNNfD_BwE

[Adam1971]

Thanks guys, I do have headers and what appears to be an Autozone starter so I’m thinking I’ll try the heat shield first.

[ga-stepside]

Originally Posted by Adam1971

Thanks guys, I do have headers and what appears to be an Autozone starter so I’m thinking I’ll try the heat shield first.

The real problem with heat soak is the relay, not the starter. When the relay gets hot it requires much more current to operate. That small ignition switch purple wire GM uses to engage the relay can’t supply enough current. A heat shield may work but adding the Ford style remote relay activated with the purple wire from the ignition switch and a large wire to feed the GM relay will work better and is cheaper.

https://www.summitracing.com/parts/sum-g1750/overview/

[franken]

The solenoid current/voltage have zero impact on cranking speed so post #5 is fiction. The solenoid could have burned contacts switching the starter, that are resistive though. Make sure the cables are good, connections are clean and the engine is grounded by the big negative cable. Not the alternator bracket, not the body. Make sure the timing is not overly advanced as mentioned, and make sure the battery is good.
Having anything tested at a parts store tells you nothing because the people that work at them know nothing.

[firedemon]

http://www.madelectrical.com/catalog/st-1.shtml

heres a guy that knows electrical not just a parts seller lots of good tech on this site . scroll to the bottom where he explains gm heat soak problems

[KQQL IT]

Get a starter from a '99 c2500 with a 7.4 draws half the load and half the size.

Spins my 406 sb with 36° initial timing with out any drag.
And another spins my 454 in my '68 like theres no spark plugs in it.

https://www.amazon.com/ACDelco-337-1.../dp/B007QBT0WA

[Eddie H.]

I used the smaller gear reduction starter from a 99 Tahoe to correct the problem on my 69 GMC.

[Adam1971]

The heat shield came in today from Summitt, I installed it and ran around town for about an hour. When I stopped for gas I shut it off and it fired right back up when I turned the key. Thanks a lot for the help folks!