Fuel pressure problem

[latteboost]

I recently purchased my first GN and I am having issues with my fuel delivery. Initially the car ran strong and the fuel pressure was set @ 43.
During a road trip the fuel pressure dropped to mid 20s and could not be increased with the regulator.
I replaced the pump with the Aeromotive 340 and replaced the filter.
The fuel pressure went to 60 lbs and could not be adjusted below 50 lbs and there was no change when the hose was reconnected.
I replaced the fuel pressure regulator with a new billet regulator from GN1 adjustable from 30 to 100 psi.
The gauge read 50 psi and shows no change when adjusting the regulator or with the vacuum line on or off.
I replaced the gauge and still shows no adjustments from 50psi with hose on or off.

Any ideas or suggestions?

The car starts and idles well but I am afraid to boost without a knowing what the actual fuel pressure could be.

The car has 60 lb injectors with chip for 91 octane. Stock turbo.

My scan aster readings are:
O2 at idle 780 to 820. I have not run at WOT due to my concern
AF 05
L8 31
Bat 13.6
Int 128
Blm 128
Mph 0
Clt 162
Ats 120
R 825
Tps .36
Iac 03 in park
Cc 240
Mal 00

It appears the tps reading is low. How do I adjust? Can I simply loosen the screws and push the sensor forward or backwards to raise it?

Can anyone recommend a tuner in the San Francisco Bay Area ?

Thanks for any help.

 

[KEVINS]

Hopefully someone more familiar with that pump will chime in but that is a BIG pump for a stock turbo/engine, IMO. It may be pumping too much fuel that the engine can't use it all and the return lines are too small to allow the fuel to go back to the tank so the pressure just builds in the line.

I'm looking at a 300 pump for my combo and I've heard that the above can happen with this size pump on my car..

Take what I mentioned above with a grain of salt just in case I'm really wrong.

Do a search on adjusting TPS.

ks

 

[buickGN3:16]

Loosen screws on the side of the tps with key turned forward '' but not running '' til the scanmaster shows .40 - .42 thats how i set mine but it really didnt affect fuel pressure


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[Nick Micale]

......
I replaced the fuel pressure regulator with a new billet regulator from GN1 adjustable from 30 to 100 psi.
The gauge read 50 psi and shows no change when adjusting the regulator or with the vacuum line on or off.
I replaced the gauge and still shows no adjustments from 50psi with hose on or off.

Any ideas or suggestions?.........

My guess is that the vent and return lines were reversed upon installation, or you have a issue with the new regulator?

Simple test, install the old regulator.

 

[psycho6cyl]

Could a kinked return line cause this?

 

[GNcollectables]

sounds like you need to do this:

http://buickturboregal.com/install-6-braided-return-line-buick-grand-national.html