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View Full Version : Fuel pressure drop @6000RPM


Flicktitty
06-25-2012, 08:11 PM
I had the 2JZ 240sx on the dyno getting tuned last week and had a fuel pressure issue where the fuel pressure would drop from 50psi down to 38 or so in the high 5000-low 6000rpm range.

I have a 2JZGTE, Deatchwerks DW300 fuel pump, 750cc FIC injectors, Aeromotive FPR, and -6AN feed line and -6AN return line. The wiring to the pump is still stock.

revving the car only to 6000rpm on 14.7psi the car made 400rwhp through a high stalled automatic in 100 degree extreme humidity day.

I'm leaning towards the factory wiring to the pump is having the pressure drop. Any other things to look into? the pump has is BRAND NEW. the rail/injectors/lines/fpr have less then 1000 miles.

jr_ss
06-25-2012, 08:31 PM
Yep, need a rewire with heavier gauge wire... Use the factory power feed as your switch 12v source and run new stuff from the relay to the pump.

Flicktitty
06-25-2012, 09:49 PM
Yep, need a rewire with heavier gauge wire... Use the factory power feed as your switch 12v source and run new stuff from the relay to the pump.

thought so, thanks for a quick response just wanted a second opinion.

cotbu
06-26-2012, 09:39 AM
I agree with the hotwire setup, but I would also test the fpr to make sure it holding up to the task.

06-26-2012, 11:37 AM
Yep, need a rewire with heavier gauge wire... Use the factory power feed as your switch 12v source and run new stuff from the relay to the pump.

yup i had the same issue, running the same pump i couldnt push passed 16psi on the pem set up witht he DW pump passed that it was dropping and jumping in fuel pressure. started at 12v and dropped to 10.5V
i hot wired it with a relay from the battery in the trunk and then got 14V on start and constant 12V with full pulls.
the pump wants Volts to stay constant kuz when boost comes in it starts flowing.

Flicktitty
06-26-2012, 01:27 PM
Thanks much guy's gonna fix that and a few other little things and back off to the dyno it goes.

06-26-2012, 02:21 PM
this is word for word what i went thru on the dyno it should fix the problem