This topic comes up on a regular basis; the car won't start when the engine is at temperature. I had this problem. I've read all the posts. It can be many things and I tried fixing them all (except one). Nothing worked. I changed the starter, I re-wired the ground to the frame. I checked the battery and all the wiring and connections. Then I redid the ground by running a separate ground wire from the battery directly to the starter. I changed out the solenoid. I put on a heat shield. Nothing worked.
I tried another starter. This time, I went with a Summit Racing mini-starter made for high compression engines (I have a mild 10:1). That fixed it. After dinking with this for a very long time, the stronger starter was the answer. Just FYI for those of you that may be dealing with this.
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