[Mk2] [Turbo] fuel pressure drop at high boost and rpm

[bambam79]

Hey, as I now solved the problem wirh the dropping boost, thank you all very much, Inow discovered the next problem.
As I am now able do drive 1.5 bar over 5000rpm my fuelpressure begins to drop and the limp mode of my ecu was activated.

fuelpressure 4,8bar at 5000rpm drooped to 4.5bar at 6000rpm. Injector duty was 75% at 6000rpm. All at about 1.5bar of boost

I have a supra fuel pump and 870 top feed injectors with the correct top feed rail from wolfkatz.
The fuel lines from the fuel pump and the fuel filter are still standard. After the filter there is the wolfkatz supported AN4 fuel line in use.

I thought the supra pump and the original fuel lines incl filter should be able to easily support 500bhp, or am I wrong?

[Nic]

The stock j-spec Supra fuel pumps are usually replaced when upping the power to 400hp and above on a Supra. A Walbro 255 of Bosch 044 pump would be better for the power you are running.

[CRAIGROBBO]

The stock j-spec Supra fuel pumps are usually replaced when upping the power to 400hp and above on a Supra. A Walbro 255 of Bosch 044 pump would be better for the power you are running.

What Nic said!....

Supra pumps will be changed out a 400hp and above - I would go down the 255 Walbro route.

Also what FPR you using? If its an Ebay no name chuck it in the bin and get a nice Aeromotive unit!

Craig

[bambam79]

Ok thank you very much. I thought the supra pump is capable of a little bit more.
My FPR is a SX Performance 15404 with 6AN fuel lines.

So the genuine Toyota fuel lines should be fine and it is just the fuel pump?

[bobhatton]

Ok thank you very much. I thought the supra pump is capable of a little bit more.
My FPR is a SX Performance 15404 with 6AN fuel lines.

So the genuine Toyota fuel lines should be fine and it is just the fuel pump?

I would change the lines and filter to min of -6 and fit a 044 fuel pump in the tank. Make sure you do not buy a Chineses copy pump, way to many around.