Injectors won't spray at high temps (80 - 90 degrees)

Hi.., so i'm facing with this exact problems for the last one week, the problems first time had when we test driving our fs car at circuit with high temp, everything was normal when it first start and It can turn off and on easily, but when it reach 83-85 degrees it suddenly won't start on, we check the injectors it won't spray until we wait the temp going down to 30 deg and it will fix itself. Both er-6n OEM injectors are new so the fuel pump.

We tested out again in our garage see if the problem still exist, first when the engine cool there's no problem at all, once we reached 85 degrees we cut of the engine and turn it on again and it was totally fine.. it can cranking & start normally, we try that method 3 times & everything was good, but when we cut off the engine and the temperatures raise up to 92 93 deg it won't start up again, injectors won't spray again, we check the voltage trough the injectors wiring and it's on, we even check the voltage using led light with 1k resistance and the led was bleeping, it's fine... there's signal trough the injectors, tomorrow we tested out & we have the exact same issues, we jumper the injectors to 12V battery and its totally spray & fine, but when we plug the wiring and crank the engine it won't spray in high temps.

Is it possible that we facing issues in our wiring harness or it's just in our ECU configuration that we missed out or there's something else...

Thankyou.

Based on the other post you made, it sounds like the cold start issue wasn't actually fuel not spraying, and adjustment of how much fuel to give the engine to start was required. With that in mind, are you confirming the injectors actually are not spraying, or does it seem like they aren't spraying because the engine doesn't start?

What is your fuel pressure during cranking?

What fuel are you running?

If you let us know engine displacement, number of cylinders, and your cranking injector pulsewidth during this condition at 92-93c vs. 85c.

It looks like your injectors flow around 250cc/min so we can ballpark the time needed.

Seems my prior reply didn't take.

With the temperature rise, there will be a small increase in electrical resistance, and drop in the current, but I don't think this is an issue.

It's a wild shot, but is that around the point where the cooling fan(s) might kick in, or some sort of auxiliary pump? Depending on the wiring, is it possible it's pulling up a ground potential (relative to battery ground) and/or down the power voltage to the injectors, relative to (nominal) 12V battery.

If it's marginal, that could be enough to prevent the injectors opening. If so, it would be even worse when cranking, as the battery voltage will be lower.

I assume you've already confirmed there is actually the correct fuel pressure in the rails?