cumminsram06

I've got a fuel pressure gauge hooked to the fuel rail on my 93Z. Previous owner put it there as part of a nitrous setup that has since been removed. At idle I'm seeing 37psi at the rail and 47psi with the regulator disconnected.

The regulator looks factory so how does this explain the increased pressure? Even if the tank in the pump was bigger or more powerful the factory regulator should still restrict the pressure just the same right?

I'm trying to nail down some tuning and it's giving me a hard time, my idle has changed from 800rpm to 1100rpm to now nearly 1400rpm with this newest tune, could it be the car just trying to learn the new fuel curves or is my fuel pressure gauge wrong and I'm leaning the car way out?

RamAir95TA

iTrader: (2)

There's nothing wrong with your fuel pressure.

defaultexistence

iTrader: (11)

check all the wiring going to the IAC as mine did this when the wires were dry rotted and grounding and shorting on each other causing IAC not to work/control idle properly, check all of harness and plugs for rot ,check IAC ---> http://shbox.com/1/iac2.jpg ,check manifold for vac leaks.
also...if you installed the BBK TB did you adjust your blades and TPS correctly? if not ---> http://www.golenengineservice.com/html/tps.html
need new harness plugs? check this site out -->http://www.bmotorsports.com/shop/pro...roducts_id/501

mines a tuned 93 and idles at 650 perfectly and i have the same fuel pressure anomaly's

fex77k

iTrader: (2)

A vacuum leak could easily cause a high idle.