FP not rising with boost


Jun 19, 2005
Just installed new racetronix pump with hot wire kit and ran a new braided feed line, however car still does not raise FP with boost? What else should I be looking for getting knock at WOT

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does the pressure go down with vacuum?

what sort of regulator do you have, and what is the fuel pressure?

I would check for vacuum at the vacuum line on the regulator with the car idling.

The last car I saw that problem on the steel feed line to the regulator was rusted shut.
Should I try blowing out with compressor? We reran from the fuel filter with a braided line but reused the front steel line

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Like TurboBob asked...

What regulator are you running and have you verified you have vacuum to it. Does the pressure change when you connect/disconnect the vacuum line?

That is what causes fuel pressure to increase, is boost (opposite of vacuum) will increase the pressure of the diaphragm to change the fuel pressure on the rail according to the boost level you are at.

Hope to help,
Assuming you have an adjustable fpr, does it raise and lower the idle pressure with the adjustment screw?