i had my TII dynoed today and it ran great so i was on the way home and it was running great withe the AFR around 11.0-11.5 then all the sudden it went lean and i couldnt boost it at all without it going lean so i pulled over and saw my FPR was only at 20psi!! so i turned it up to 30 and it was fine then later down the road i pulled over and it was at 40 so i was like wtf is going on!! could the regulator be takin a ****? its a sard regulator and its only a year old

 

Maybe your fuel pump is crapping the bed. Would explain the jump back up after you cranked the FPR up.

 

its a brand new supra TT pump so thats really unlikely but it is possible im still leaning more towards a bad regulator

 

could be bad voltage going to the pump, ive heard and by experience that fuel pumps either work or dont work. I have my regulator set at least 40 psi.

 

So what is this like a digital regulator with a display on it saying 20 psi or what?

 

lol..no the regulator has a analog guage on it from jegs. all aftermarket FPR have a guage otherwise you wouldnt know where to set it

 

Fuel pickup sock clogged? Clogged filter? Bad pump?

I'd look at those before assuming the regulator is bad as they almost never fail (it's just a diaphragm and a spring).

 

Also check for a pinch in the Vac line to the FPR.

 

I agree with Aaron start with the easy stuff like fuel filter and pickup sock.

 

yeah but the thing is i just instaled the pump like 1 month ago and i replaced the filter about a year ago..i just dont understand what would cause the fuel pressure to drop from 30 to 20 then up to 40 then back down to 30...thats what leads me to belive the FPR is whats wrong with it.. i didnt think the things aaron mentioned could cause the pressure to drop and rise i could see how they could make it drop but not rise

 

well if the sock gets clogged there is ur drop... then say u went around some corners and sloshed the gas around in the tank and washed the stuff off the sock then ur pressure would rise again correct???i kno its possible cause i bought a ford probe one time that had a **** load of rust in the tank(got the car running for 50 bucks)and it would start to run bad and ide have to swing the thing all over the place to get the **** off the pump sock then it would run fine for a while....

 

when i put the pump in the inside of the tank it looked mint and it was shinny with no rust

 

i went ahead and orderd a new FPR so well see how it works...the car seems to stay around 10.5 to 11.5 on the AFR if i start out in first and keep it floored but if i start in 3rd or 4th it goes lean as soon as it goes into boost...weird

 

I still don't think it would be the FPR, but we'll find out soon enough I guess.

Personally I would suspect an intermittent fuel pump or electrical connection (fuel pump connector, relay, etc.) if the filters are OK.

Don't assume that new parts are automatically good. I spent 3 months chasing an ignition breakup problem on a GSL-SE only to find a bad brand new MSD coil.