SR Hesitation at 3.5k+ - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

DLo Eric · 10-08-2007, 01:25 PM

Alright so I have a problem thats been bugging me for a few months.

Stock Blacktop SR
T25
HKS Hi Power 2.5''

When I would accelerate above 3.5k the car would more or less hesitate. There isnt any bucking involved. Just a bit of a slow down when coming to that point. Anything more than 15% throttle will induce the hesitation.

Maf has been changed out a couple of times
TPS is reading correct.
Timing is at -15.

What I'm feeling (no boost gauge) is full boost all the way even when its hesitating, it just doesn't want to move much faster.

The only thing I can think of is poor air flow at higher rpms considering the downpipe is 3'', gutted cat and the exit piping is 2.5''.

Now is there something I'm forgetting to check? or should I swap the 2.5'' on the car to my other 240's 3'' exhaust?

sliEighty · 10-08-2007, 01:41 PM

check for boost leaks even a small one can effect the way it runs

DLo Eric · 10-08-2007, 02:10 PM

Quote:

Originally Posted by sliEighty

check for boost leaks even a small one can effect the way it runs

Yeah, I've switched out the piping completely with another sidemount I have. It still doesn't make a difference

Kouki · 10-08-2007, 08:42 PM

I had something very similar happening to my sr, changed the plugs, ran great after that. But yeah, I have a boost gauge, and it was spooling all the way up to 14psi like normal, but just felt like I had the brakes on, then if I lifted off the throttle, and really eased into it, then it would run out fine, I'd check your plugs first.

sliEighty · 10-08-2007, 08:47 PM

check the ecu for codes maybe?

DLo Eric · 10-08-2007, 10:35 PM

Quote:

Originally Posted by Kouki

I had something very similar happening to my sr, changed the plugs, ran great after that. But yeah, I have a boost gauge, and it was spooling all the way up to 14psi like normal, but just felt like I had the brakes on, then if I lifted off the throttle, and really eased into it, then it would run out fine, I'd check your plugs first.

Changed the plugs in attempt to fix the problem. It's running NGK Iridium 7-heat range. Didn't seem to do anything.

Quote:

Originally Posted by sliEighty

check the ecu for codes maybe?

Not throwing any codes either, thats the first thing I did :/

tt99ol · 10-08-2007, 11:03 PM

try using regular bkr7e plugs iridiums seem to not run right ever also do you have an atmospheric bov it might be leaking

attracted · 10-08-2007, 11:24 PM

check for dirt in ur gas tank....pump might be on it's way

i had a similiar problem

rightcoastimports · 10-08-2007, 11:41 PM

sounds like a fuel problem.. if you dont have a walbro pump i'd get one in there.. they are under $100.

srgabe · 10-09-2007, 05:07 AM

you know what dude i got the same problem execept my slight hesitation is around 5000 rpm and up so i put a walbro and a sard fpr and still nothing i was running the same iridiums then changed to the ones the guy above suggested and still nothing idk what it is i was thinking maybe i need to adjust my afc??...so if you find out please lmk

Sileighty_85 · 10-09-2007, 09:21 AM

Mines doing a similar thing when mine started it was throwing a code for the CAS but it went away, but im still thinking thats the prob and the CAS is out of spec

smelly240 · 10-09-2007, 05:18 PM

I remember my car felt like it had vtec - turns out the stock timing is whack

Luvs2slide · 10-09-2007, 05:35 PM

Quote:

Originally Posted by srgabe

you know what dude i got the same problem execept my slight hesitation is around 5000 rpm and up so i put a walbro and a sard fpr and still nothing i was running the same iridiums then changed to the ones the guy above suggested and still nothing idk what it is i was thinking maybe i need to adjust my afc??...so if you find out please lmk

Your SR won't make much power after 5500. After that the power band starts dying on a stock setup.

makulit054 · 10-09-2007, 06:52 PM

Mine hesistated because my CAS wasn't plugged in all the way. Make sure your CAS is plugged in all the way.

DLo Eric · 10-09-2007, 09:39 PM

Quote:

Originally Posted by makulit054

Mine hesistated because my CAS wasn't plugged in all the way. Make sure your CAS is plugged in all the way.

You know, I did notice the plug for the cas was cracked. It's plugged in, but is there a possibility that would cause to to hesitate at higher RPMS? Its constant throughout all gears. Any place where I can get plugs for the cas?

posdriftin · 10-12-2007, 01:55 PM

mine did the same thing also.. i cleaned the maf (lightly with brake clean) and cleaned the throttle body with a wire brush and carb clean.. then ran at high rpm for 15-30 seconds.. runs awesome now

10-08-2007, 01:25 PM	#1
DLo Eric Zilvia Member Join Date: Apr 2004 Location: Las Vegas Age: 38 Posts: 245 Trader Rating: (2) Rides Gallery: DLo Eric Feedback Score: 2 reviews	SR Hesitation at 3.5k+ Alright so I have a problem thats been bugging me for a few months. Stock Blacktop SR T25 HKS Hi Power 2.5'' When I would accelerate above 3.5k the car would more or less hesitate. There isnt any bucking involved. Just a bit of a slow down when coming to that point. Anything more than 15% throttle will induce the hesitation. Maf has been changed out a couple of times TPS is reading correct. Timing is at -15. What I'm feeling (no boost gauge) is full boost all the way even when its hesitating, it just doesn't want to move much faster. The only thing I can think of is poor air flow at higher rpms considering the downpipe is 3'', gutted cat and the exit piping is 2.5''. Now is there something I'm forgetting to check? or should I swap the 2.5'' on the car to my other 240's 3'' exhaust?

10-08-2007, 01:41 PM	#2
sliEighty Zilvia Junkie Join Date: Jan 2006 Location: Central pensyltucky Posts: 471 Trader Rating: (3) Feedback Score: 3 reviews	check for boost leaks even a small one can effect the way it runs __________________ livin on the east cost is harder then you think... ECM for life lll

10-08-2007, 08:47 PM	#5
sliEighty Zilvia Junkie Join Date: Jan 2006 Location: Central pensyltucky Posts: 471 Trader Rating: (3) Feedback Score: 3 reviews	check the ecu for codes maybe? __________________ livin on the east cost is harder then you think... ECM for life lll

10-08-2007, 11:41 PM	#9
rightcoastimports Zilvia Addict Join Date: Jul 2006 Location: Boston Area Age: 40 Posts: 663 Trader Rating: (15) Feedback Score: 15 reviews	sounds like a fuel problem.. if you dont have a walbro pump i'd get one in there.. they are under $100. __________________ 95 SR Zenki \| @ e_form daily - A34 Maxima \| A36 Maxima

10-09-2007, 09:21 AM	#11
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Mines doing a similar thing when mine started it was throwing a code for the CAS but it went away, but im still thinking thats the prob and the CAS is out of spec __________________ 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

10-08-2007, 08:42 PM	#4
Kouki Zilvia Addict Join Date: Feb 2005 Location: Nebraska Age: 40 Posts: 727 Trader Rating: (3) Feedback Score: 3 reviews	I had something very similar happening to my sr, changed the plugs, ran great after that. But yeah, I have a boost gauge, and it was spooling all the way up to 14psi like normal, but just felt like I had the brakes on, then if I lifted off the throttle, and really eased into it, then it would run out fine, I'd check your plugs first.

10-08-2007, 11:03 PM	#7
tt99ol Zilvia Addict Join Date: Jan 2005 Location: quartz hill CA Age: 38 Posts: 644 Trader Rating: (8) Feedback Score: 8 reviews	try using regular bkr7e plugs iridiums seem to not run right ever also do you have an atmospheric bov it might be leaking

10-08-2007, 11:24 PM	#8
attracted Leaky Injector Join Date: Sep 2005 Location: montreal Posts: 55 Trader Rating: (0) Feedback Score: 0 reviews	check for dirt in ur gas tank....pump might be on it's way i had a similiar problem

10-09-2007, 05:07 AM	#10
srgabe Leaky Injector Join Date: Jul 2007 Location: honolulu Posts: 50 Trader Rating: (0) Feedback Score: 0 reviews	you know what dude i got the same problem execept my slight hesitation is around 5000 rpm and up so i put a walbro and a sard fpr and still nothing i was running the same iridiums then changed to the ones the guy above suggested and still nothing idk what it is i was thinking maybe i need to adjust my afc??...so if you find out please lmk

10-09-2007, 05:18 PM	#12
smelly240 Nissanaholic! Join Date: Oct 2006 Location: Philaburbia Age: 47 Posts: 2,137 Trader Rating: (4) Feedback Score: 4 reviews	I remember my car felt like it had vtec - turns out the stock timing is whack __________________ HREs on a S13 - check, 6262 - check, Girlfriend.... - nope

10-09-2007, 06:52 PM	#14
makulit054 Zilvia Member Join Date: May 2007 Location: socal Posts: 215 Trader Rating: (1) Feedback Score: 1 reviews	Mine hesistated because my CAS wasn't plugged in all the way. Make sure your CAS is plugged in all the way.

10-12-2007, 01:55 PM	#16
posdriftin Zilvia Addict Join Date: Apr 2007 Location: so cal...north ..sd... Posts: 832 Trader Rating: (7) Feedback Score: 7 reviews	mine did the same thing also.. i cleaned the maf (lightly with brake clean) and cleaned the throttle body with a wire brush and carb clean.. then ran at high rpm for 15-30 seconds.. runs awesome now