View Full Version : rb20 studdering, boost falling off.. stumped.

03-20-2012, 06:27 PM
so ive had my car running fine for months now.. and it seems like the past week or so its been acting funny.. when the motor is cold you can drive it normally and about 2 thousand rpm you can feel a complete power loss and it feels like death until it hits boost then it will rip decent till about 4 -4.5k and then boost kinda falls off and it sputters and putts and doesnt go. i had my car fogged at my uncles shop and found all my boost leaks and i have a perfect 19-20psi at idle when its warm. my first thought was maybe a boost leak but what else could it be? sounds almost like its fuel cutting but its completely stock and i havent had a problem until like i said the past week or so :confused: HELP MEE haha shits wack yo!

03-20-2012, 06:32 PM
what Fuel pump do you have?

What brand and heat range are the spark plugs? what are they gapped at.

try cleaning MAFS

03-20-2012, 06:38 PM
i believe a stock fuel pump. i mean i figured thatd be fine since rb20's only have like 270cc injectors.. and its been fine thus far.. unless its taking a shit. but i got ngk bpr6es' i think i can remember exactly deff 6's though and gapped at .020

and i thought about cleaning the maf because i was having an issue where power steering fluid was pissing out of my reservoir and my intake and maf is right next to it.. i thought maybe it had sucked some onto the sensor? its a possibility i guess wont hurt to try!

03-20-2012, 06:52 PM
yo need a bigger fuel pump. Inj. size is not as a big deal its the HP/Boost reason. You go from a 4 Cylinder 115hp N/A engine to a 6 cylinder 200+ HP Engine. Even SR's need the bigger fuel pump.

Open the plug gaps to .028

03-20-2012, 08:26 PM
but why would it all of a sudden start shitting out? cause i mean its ran fine for months now all of a sudden its running like crap. ill snag a walbro or something and throw it in. my buddy with his rb said his did the same thing until he swapped out for ls1 coils

03-21-2012, 11:37 AM
Anyone else got any input? Cleaned my maf and still stutters. Just looking got ideas