Hey guys nice new site! Well I am posting on a little problem/regard about my fuel pressure regulator. I made the stock fuel pressure regulator, adjustable. MY question is, in what position/ turns do you guys set it too. I am asking this because i have played with the fuel prssure regulator starting from 5 turns to recently 1 1/2 turns. The car is running good but has a little bog on top end, And also dont want to lean out the motor and blow it. Thanks for looking at my post -Eric

 

The number of turns is too subjective. You need a fuel pressure gauge. Set it to 11-13 psi. You're just farting in the wind otherwise.

 

Well i have a fuel pressure gauge on the pressure side, But my question was it seems to me that i have the regulator a little to closed, Thats why i am asking what other of you guys do (how many turns)? Thanks

 

You should measure the f.p. with the stock regulator setting....

but now you have lost that setting by making the stock f.p. reg adjustable.

IF the motor is somewhat in stock condition, a good strating point is 11.5 psi with the motor idling.

IF the motor has more cam, compression or other SLIGHT mods then bump the fp to about 12 psi. A little fp goes a long way. One clue is low speed drivability and possible mil light on under full throttle/higher rpm...which indicate more fp needed.

Absolutely pinpointing what the motor is most happiest with means dyno time to adjust the fp under load to get the rite air/fuel ratio....but you can come close by ear and seat of the pants. The more you crank on the regulator above about 12.75 psi , the more you shorten the life of the pump.

 

How did you do this?

 

All my mods are on my sig. I am at one turn open and it is running and ideling alot better. I made my stock fuel pressure regulator with these instructions. https://www.thirdgen.org/tech/tbi-afpr.shtml

Thanks

 

Man you guys are farting in a tornado

Adjusting the FP like you are is messing with the ECM pretty bad, without knowing which way you need to go you should just leave it alone. If your datalogging and see that your universaly lean or rich, then a FP change might help, but in reality that rarely happens. You usually need less fuel in one place and more in another.

 

I just changed my sparkplugs and according to the techs at the dealership I work at, they indicate my car runs lean. I have a cable to data log, just don't understand what the charts mean. Would this help to fix this?

Kris

 

Probably not, your ecm uses the O2 sensor to constantly keep your AFR at 14.7 to 1 no matter what your fuel pressure is, it's only at WOT and cold start times that messing with the FP would change the way the motor runs. I would suspect your O2 if you really are lean.