So my 1jz is running a bit wierd. i had it running great in my supra. i did everthing right everything works but i installed a 255 fuel pump in the sc300, my question is do i need to get an adjustable FPR? the car is running way rich, and when i do step on it it only wants to go to 4,200 RPM parked or moving before its starts to chug. if i step on the gas slowly it will go up to 5000 rpm ok. but still kinda seems like somethings stopping it, i have stock everything on the 1jz. and my spark plugs were gapped at .40 but i went back to how i had them in the supra to .35.

 

Check supramania.com

Recommended gap on the 1jz is less than .030, more like .022-.028

You shouldn't need an adjustable fpr to fix a rich condition.

 

what if i go back to a stock sc300 fuel pump? if i remember correctly when i had the stock Fuel pump just a few days ago it would rev up way high to 7 at least. but now that i got the 255 i think that my be my problem. ill see what happens when i switch em. anyone ever experience this? i think im going to do that 12v mod also

 

I'm not sure that would be the problem. The stock FPR could be bad, injector could be leaky.

You need to do the 12v mod with the walbro, its not designed as a dual flow rate pump.

 

So my friends went and messed with my car, they went back to the stock fuel pump it goes up to 5000 rpm now but only when your trying to boost, if you go up slowly it will go up to 7000rpm just fine because they blew a coupling and it drove just fine cause they werent boosting, im thinking maybe the maf sensor? is there a way of testing it?

 

check supramania.com They are the 1jz gurus.