Starter when Engine is Warm is not consistent.

[TDecker]

When I start my '80 FI 2000 cold, the engine cranks just fine and starts right up consistently. However, after I've driven around a bit, and the engine is warm/at operating temperature, if I shut it off and restart, occasionally, the starter engages but then stops as if I have a dead battery. I can immediately try again and the engine turns over and starts up (with possibly a slightly weak turnover.)

So far it has only happened once the car has warmed up, everything is fine when cold. I'm going to get the battery tested, just in case, and I'll check the alternator output while I'm at it. Where else should I look? Is it possible the starter is binding up when warm from the engine? If so, is the only solution to replace/rebuild it? Or is it more likely some electrical connection failing with heat?

I should note that the starter is original, the car has somewhere around 55000 miles on it, and I haven't begun to add relays to the headlights, wipers, etc.

Any thoughts would be appreciated!

[DieselSpider]

Before going too far check your battery first as it may not have sufficient voltage to deal with the compression when the engine is hot. You can also get this effect if the cooling system is not up to snuff and the cylinders get heat soaked. Valves out of adjustment can also add to difficulty starting a heat soaked engine.

Its not always the starter or electrical connectors however a marginal battery can lead to starter and other electrical system failures.

[18Fiatsandcounting]

I have had a couple of Fiats that had exactly this symptom: the starter motor acts normally when cold, but all I get is a "click-click" sound and minimal engine turnover when it's warm, like a weak battery. The issue was that the copper contacts in the starter motor solenoid were corroded or otherwise compromised, and they just didn't make good electrical connection when warm. A new solenoid (or carefully disassembling the old solenoid and renewing the contacts) fixed the issue.
These solenoid contacts have to carry a couple hundred amps or so when starting the car, and time + oil residue + heat just fouls them up.

-Bryan

[TDecker]

Thanks for this!
Tristan