rb20 studdering, boost falling off.. stumped. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

two40guy · 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

HELP MEE haha shits wack yo!

Sileighty_85 · 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

two40guy · 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!

Sileighty_85 · 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

two40guy · 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

two40guy · 03-21-2012, 11:37 AM

Anyone else got any input? Cleaned my maf and still stutters. Just looking got ideas

03-20-2012, 06:27 PM	#1
two40guy Zilvia Junkie Join Date: Sep 2009 Location: binghamton,ny Posts: 442 Trader Rating: (9) Feedback Score: 9 reviews	rb20 studdering, boost falling off.. stumped. 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 HELP MEE haha shits wack yo!

03-20-2012, 06:32 PM	#2
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	what Fuel pump do you have? What brand and heat range are the spark plugs? what are they gapped at. try cleaning MAFS __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

03-20-2012, 06:52 PM	#4
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	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 __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

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03-20-2012, 06:38 PM	#3
two40guy Zilvia Junkie Join Date: Sep 2009 Location: binghamton,ny Posts: 442 Trader Rating: (9) Feedback Score: 9 reviews	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, 08:26 PM	#5
two40guy Zilvia Junkie Join Date: Sep 2009 Location: binghamton,ny Posts: 442 Trader Rating: (9) Feedback Score: 9 reviews	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	#6
two40guy Zilvia Junkie Join Date: Sep 2009 Location: binghamton,ny Posts: 442 Trader Rating: (9) Feedback Score: 9 reviews	Anyone else got any input? Cleaned my maf and still stutters. Just looking got ideas