I have 1992 3.1L Camaro.
It run EXTREMELLY rich so I decided to install adjustable fuel pressure regulator. I looked for inline adjustable regulator but suddenly bumped on fuel rail regulator

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D512%2D501&N=115&autoview=sku

It is for 5.0 engine but the fitiing looked very similar to stock installed on 3.1. I have made inquires to Holley but got no answer. So I have decided to risk and bought it.

It was easy installed on fuel rail and now it is easily accessed to tune.

I also installed fuel pressure gauge to see actual fuel pressure.

After all work was done I started to play with pressure and found that I can easily decrease fuel pressure down to 20 psi without lack of power.

Gas mileage also decreased down to 13 liter/100 km.

Peter,

Moscow, Russia.

 

Your MPG decreased due to less atimization (sp?).

If you were running rich at stock pressure, then something else was wrong with your engine. Bad spark, leaky injectors, o2 sensor wack.. etc.