Fuel Boiling

[R32moneypit]

With the hotter weather we have been having. It seems that my fuel temps are too high and causing the fuel to boil and leaning out the car.Seems to only occur at lower speeds when things get heat soaked followed by a WOT blast. A/F gets close to 13Highway cruising followed by a WOT blast the A/F remains in spec 11.xx to 12.5I am running; -7, greddy pipes, Pon cams, Haltech Platinum, full exhaustMaking 450 AWHP at 21psi on VP100I am running Siemens Deka 880 injectors with a Tomei in tank pump. Other wise fuel system is stockIs there a potential issue with the fuel system or am I maxing it out?Thanks in advance for your thoughts

[Dragon Humper]

Unless you wrapped the fuel line around the exhaust pipe, boiling is nearly impossible. Where are you lean? The AF #s you posted are fine, even a little rich at cruise. Mine are in the 15 zone at cruise, that's how i get good hiway mileage on my beastie .



Jon.

[R32moneypit]

Thanks for the reply Dragon

The A/F is 11.5-12.5 at WOT

In the heat soaked lean out situation its 12.9-13.2 again at WOT

The cruising A/F is in the mid teens

Where is the safe limit of A/F for WOT and full boost?

[Skym]

Under 12's (11.4-11.6 is safe) when at full boost and that continues to rev limiter.

Engine has cams, so it should run richer than normal at idle, off boost, etc, idle rpm is higher.

Fuel does heat up if fuel pressure is higher (due to higher lph fuel pump), as more fuel is moved to and from hot engine (N1 GTR has a fuel cooler when fuel pump is hardwired).

Check that fuel pump is hardwired (getting the required voltage). Leaning out like that seems like the fuel pump isn't hardwired to get 13.5 volts+ (factory can go from 12volts to 10 volts at higher rpm, which looks like what it is doing and tune needs to be tweeked to suit). Also check stock FPR (check fuel pressure, pull hose off FPR, block nipple on intake plenum to see if fuel pressure rises 7.1psi or so).

[Bruizer]

What is the actual fuel temp (to know its boiling that is, which is gonna burn/explode before boiling).

Even if your fpr didn't work and you didn't have returning fuel, it wouldn't cause major issues. You could lean out however if your fuel gets hot and you don't have fuel temperature compensation (fuel temp to ecu). Haltech has an ethanol content sensor that can digiout the fuel temp to the haltech.

Sounds like your car runs ok (afr wise).

I have a cooler (-10 return, setrab 10 row) for my fuel but have 1 tomei and 2 bosch 044 fuel pumps and still daily drive. My temps are cooler than stock