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Fuel pressure drop-off, what to do?

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Old Dec 6, 2008 | 12:34 PM
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Question Fuel pressure drop-off, what to do?

Just finished a GT40R setup, started the mapping today. I have the following fuel setup.

Supra Fuel pump
FPR
1000 Pri, 1680 Sec

The turbo is currently spooling up to 1.4bar as the wastegate spring isn't kicking in, so need change the spring so it kicks in around 1bar. However, the fuel pressure is rising to 50 psi at about 4500rpm, then starts dropping off and the AFR goes lean so I need to get more pressure in to the fuel system as far as I can tell.

I'm thinking of adding a Bosch 044 pump inline, externally mounted, to maintain the pressure. I'm going to be mapping for around 1.5bar. My question is this, will adding the bosch pump inline give enough of a boost to the fuel pressure, or do should I be looking at another setup?

Any opinions and view welcome.

Cheers,
Lenny
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Old Dec 7, 2008 | 01:41 AM
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have you re-wired the pump? the stock wiring is a joke...
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Old Dec 7, 2008 | 03:34 AM
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No I haven't. We were going to check the voltage on the pump. So standard wiring, the pump won't see the full battery voltage?

Also the PFC Commander/Datalogit shows an alarm on the pump voltage. Always show's 4.98v. Never though anything of that before......
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Old Dec 7, 2008 | 06:13 AM
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That reading is just the fuel temp sensor, which you eliminated when installing the 1600 secondaries.

Wire a relay to the pump so that it sees constant 12v battery voltage. Use the current pump hot wire as the trigger for the relay, this way it will not run continuously when you just have the key in the on position.
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Old Dec 7, 2008 | 10:43 AM
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Thanks for the info BR, and for some great products I've had of you guys
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