Q: I raised my boost pressure, now the car stops and shakes when I get the boost going faster
A: You have found fuel cut.
Fuel will stop being pumped into the engine if the Toyota ECU detects 12 psi on ST165/ST185, and 17 psi on
ST185RC/ST205 models. The Toyota ECU is set to activate fuel cut if it detects 4.4 volts from the Turbo pressure
sensor. The Turbo Pressure Sensor is reading boost from your intake manifold and puts out 4.4 volts (roughtly)
at a certain boost level. First, if you haven't purchased/installed a boost gauge, please do so. This is vital
to the tuning you are about to do. Second, to disable fuel cut we just have to stop the computer from seeing
4.4 volts under any conditions. Go the MODS section to find out how.
Q: I want to install a Supra TT fuel pump, is it hard?
A: No, it bolts right in.
If you can replace your fuel pump, then you can certainly install a Supra TT.
Being that it's a Toyota piece, it bolts right in. Here are some pics.
ST185 Pump Supra TT Pump Supra Pump On Celica Bracket
Q: Can I put in a Supra Fuel Pressure Regulator for high performance?
A: It may be possible, but the 2 are completely different in size and mounting. Alot of
custom work would be required, for little or no gain. If you are daring enough here
are the numbers:
ST185 FPR ND# 0970 83280 74070
JZA80 FPR ND# 2110 23280 46030
Q: I'm searching for replacement upgrade injectors. What type do we have?
A: See the fuel tuning page. Here is a quick rundown:
ST165 Low Impedance, Top Feed, Nippondenso style (440cc)
ST185 Low Impedance, Side Feed, Nippondenso style (440cc)
ST205 Low Impedance, Side Feed, Nippondenso style (540cc)
Fuel Pump Specs
|Holley In Tank Fuel Pump||190lph/225lph 425/575hp|
|Walbro 255||213 lph(40psi) @ 12v 255 lph(40psi) @ 14v|
|RRE DENSO Upgrade (eclipse)||150lph(43psi) @ 12v 210lph(43psi) @ 14v|
|Supra Twin Turbo||260lph(43psi) @ 12v 290lph(43psi) @ 14v (650 / 775 hp)|
|3000gt VR4 / Celica Gt4||180lph(43psi) @ 12v 225lph(43psi) @ 14v (estimated)|
|RX7 Twin Turbo||210lph(43psi) @ 12v 260lph(43psi) @ 14v (estimated)|
|HKS In Tank Upgrade||250lph(43psi) @ 12v|
|Bosch||0 580 254 984|
Some specs courtesy RRE Fuel FAQ, careful, some of the max flow ratings of popular upgrade fuel pumps are at 14v, not 12v.
Fuel Injector Specs