96 starting issue - fine cold, not so fine hot

Ok, about a year & a half ago, the engine started requiring me to push the go pedal some to get it to start, and it wouldn't idle worth a crap (not really driveable). Cleaned IAC, and it got better for about a month, then same issues. This time, I replaced the IAC. Worked fine till a few weeks ago.

Started doing the same thing again, so I replaced the IAC under warranty. It got better for about a day.

Current symptoms, if the engine is cold, it starts up just fine, slight rpm jump to ~ 1000 rpm, then down to 750 or so. But, if the engine is hot, it either barely starts and at 600-750 rpm, or it requires some throttle input to start. Once it is started, it runs & idles fine.

Where should I look for the problem ? IAC is new, but nothing else is that I am aware of, and I've had it for 3 yrs now.

Do a search on heat soak. There was a TSB on this.

Edit: Heat soak is also a possibility. All your tune-up parts fresh ? Any weeping fuel injectors ?

....it requires some throttle input to start. Once it is started, it runs & idles fine.

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Common symptom of a low voltage issue from:
• leaving the lights on
• a failing battery
• a failing alternator
• dirty or loose wire connections
• internally corroded wires

Perform routine maintenance of the start and charge systems. Remove, clean, and firmly reconnect all the wires and cables to the battery, starter, and alternator. Look for corroded or damaged cables or connectors and replace as needed. Do the same for the grounding wires from the starter to engine block, and from the battery and engine to the Jeep's frame/body. You must remove, scrape, and clean until shiny, the cable/wire ends, and whatever they bolt to. Jeeps do not tolerate low voltage, bad connections, or poor grounds.

Have the battery, starter, and the alternator Load Tested for proper function in a test machine that applies a simulated work load. Handheld testers are inaccurate and will often pass faulty parts.