G'day all, just lately in this hot weather i have been having trouble with my fuel system. If i get down to half a tank or so i lose line pressure. The fuel in the tank gets very hot and could be vapourising. If i go and fill up then i dont have any probs and if it is a cool day i have no probs. The car has been on the road for 2 1/2 years and 30,000 miles and have not had this problem before this year. I have 2 pumps, one feeding the surge tank then the inj pump. Return line to surge tank then to main tank via filler tube. Am toying with putting a cooler on the return line but since i had no probs in the last couple of summers i could be wasting my time. Rail pressure when running is always at 40 psi. Anyone got any other ideas besides putting it on LPG
The 1UZFE EGR Delete Kit is available for sale here.
spf_lexus
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What can be happening is that when the tank gets low, the fuel wont absorb as much heat before it vaporizes and when it does your getting vaporlock in the fuel lines. When you fill up more fuel on the same hot day, the extra fuel can absorb the heat and you get your line pressure back.
You can always install a ball valve made for fuel systems and re-route your main fuel supply line(s) through a large cooler w/ a simple elec./mechanical switch and when summer ends and winter starts, close the valve and go back to stock.
You can always install a ball valve made for fuel systems and re-route your main fuel supply line(s) through a large cooler w/ a simple elec./mechanical switch and when summer ends and winter starts, close the valve and go back to stock.
spf_lexus
Active Member
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- Murrieta California
Do you have any headers or turbo manifolds installed near your fuel lines? I have had my sc400 out on 110 degree days w/ the low fuel light illuminated and I never have vapor lock issues but its not to say its improbable. Also, make sure you have some sort of vapor purge for the tank so that vapors and fuel thats changing state do not get pulled into the lines.
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Too much fuel is being recirculated and is getting heated in the process. Also, the hotter it gets, the lighter it'll get, and you'll make less power.
Reduce the voltage to the fuel pump during idle and cruise (high vacuum) conditions. If you're running aftermarket EMS and have a spare output that can do PWM that'll work. Usually a spare injector output can be used, but it can't handle the current, so you use that output to "pilot" a larger SSR. I can send you a circuit.
If not, you can try getting a fuel pump resistor box from an older Toyota and that'll drop it to around 9v IIRC.
There's really good reasons why the OEM's put some of this stuff on. This is one of them.
A fuel cooler will help as well, but preventing the problem from happening is a better solution than fixing it after it's happened.
Reduce the voltage to the fuel pump during idle and cruise (high vacuum) conditions. If you're running aftermarket EMS and have a spare output that can do PWM that'll work. Usually a spare injector output can be used, but it can't handle the current, so you use that output to "pilot" a larger SSR. I can send you a circuit.
If not, you can try getting a fuel pump resistor box from an older Toyota and that'll drop it to around 9v IIRC.
There's really good reasons why the OEM's put some of this stuff on. This is one of them.
A fuel cooler will help as well, but preventing the problem from happening is a better solution than fixing it after it's happened.
