Rb25 new setup issues - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

PaliRB · 03-01-2017, 03:41 PM

Just finished installing hx35 on my rb25 mods list:
Stock s1 rb25
Freddy IM
Ls coilpacks
Tial 44mm wg
3"exhaust all the way back
Z32 maf
Enthalpy tuned ecu
750cc injectors

So my issue is the car idles at 10.1-10.5 afrs. I checked the tps and im getting .46v closed throttle 4.16v wot, I cant find any vac leaks and dont really know where to go from here, also feels sluggisg getting into boost.

rawgarage · 03-01-2017, 04:31 PM

that enthalpy tune?

PaliRB · 03-01-2017, 04:39 PM

What about it?

ThePaddy · 03-01-2017, 05:58 PM

Is the tune correct for the setup you have

Eg z32 maf and 750 CC

If it's a chip tune do you have a consult scanner and any ECU errors?

PaliRB · 03-01-2017, 06:15 PM

Yes i just checked my ecu codes and im getting 21 and 34 for knock sensor and cas

ThePaddy · 03-01-2017, 06:25 PM

You'll need to fix them then recheck it's probably in limp mode

KAT-PWR · 03-01-2017, 07:30 PM

Check injector o rings as well. Common issue

PaliRB · 03-01-2017, 07:43 PM

Got it thanks, will check it out tomorrow after work and give you guys an update

rawgarage · 03-01-2017, 09:42 PM

check it now damn it....fuck work...

feito · 03-01-2017, 09:48 PM

^lol

PaliRB · 03-02-2017, 05:37 AM

Got to go to work,lol.

PaliRB · 03-02-2017, 09:21 AM

Found out one of my plugs in my knock sensor subharness doesnt lock into the the knock sensor, getting another knock sensor subharness. Hopefully it is just a connection that was coming loose causing my car to run rich at idle and causing me to get code 34 as well. Btw i have ls coilpacks and gonna go back to the stock coilpacks to see if this helps.

PaliRB · 03-02-2017, 12:59 PM

Is the code because knock is being detected or is it a failure somewhere in the circuit

RB25GUY · 03-02-2017, 01:23 PM

Quote:

Originally Posted by PaliRB

Is the code because knock is being detected or is it a failure somewhere in the circuit

failure in the harness, i would say check MAF and make sure your cas is set properly.

PaliRB · 03-02-2017, 01:30 PM

What rpm do you guys time your rb's? I hear people say 900 800 750 650? The fsm says 650 +/- 50 rpm

RB25GUY · 03-02-2017, 01:42 PM

mine always was at 700

PaliRB · 03-02-2017, 01:44 PM

I honestly think its the maf where should i start at

PaliRB · 03-02-2017, 05:06 PM

What approach should i take to diagnose the issue?

Kingtal0n · 03-02-2017, 09:49 PM

You check fuel pressure,
pressurize the plumbing for leaks to 15psi~
check you are using the correct maf,
make sure you have the right tune in the chip,

fueling is basically maf -> ecu -> Injector
so this is the entire chain of command I have suggested above.
If it still runs rich at idle, dial it down using a SAFC type device, OR get somebody to re-tune the chip. Not all 700~CC injectors are identical, so a tiny change in the fuel map, engine idle vacuum, idle conditions, pulse dead-zone (delay) as voltage at the injector adjusts the delay and so forth, it is too many variables for a "canned tune" as you move up in injector size. In other words, the larger the injector, the more unknown the injector, the less likely you will be "in the correct region" at low injector pulse widths such as around idle.

PaliRB · 03-02-2017, 10:05 PM

Fuel pressure is at 38 psi at idle, using n62 maf. I checked with my tuner about my setup and he said he tuned for the same setup. My problem only occurs on idle the closer the car comes to warming up the richer it gets until it reaches in the low 10afr range and it bounces between 10.9 and 10.3afr. Checked my tps and I am getting .46v closed throttle 4.16v wot maf is .4v ign on eng off and 1.2v eng on so both maf and tps are reading good. Checked to see if my injector o- rings are leaking and nothing as far as I can tell. I also swapped back to the factor coils and igniror setup and it didnt make a difference and the codes 21,34 returned

PaliRB · 03-03-2017, 10:41 PM

*UPDATE*So today I found some interesting things. Pulled my cas and could barely turn it by hand, knowing at the very least the bearings are shot I borrowed a known working cas hooked it up, deleted the codes and with the ignition switch on engine off spun the cas by hand for a minute or two and checked the codes again and code 21 is gone so waiting to order a new cas and hopefully my issue will be resolved

03-01-2017, 03:41 PM	#1
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Rb25 new setup issues Just finished installing hx35 on my rb25 mods list: Stock s1 rb25 Freddy IM Ls coilpacks Tial 44mm wg 3"exhaust all the way back Z32 maf Enthalpy tuned ecu 750cc injectors So my issue is the car idles at 10.1-10.5 afrs. I checked the tps and im getting .46v closed throttle 4.16v wot, I cant find any vac leaks and dont really know where to go from here, also feels sluggisg getting into boost.

03-01-2017, 05:58 PM	#4
ThePaddy Join Date: Oct 2013 Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	Is the tune correct for the setup you have Eg z32 maf and 750 CC If it's a chip tune do you have a consult scanner and any ECU errors? __________________ Using Tapatalk

03-01-2017, 06:25 PM	#6
ThePaddy Join Date: Oct 2013 Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	You'll need to fix them then recheck it's probably in limp mode __________________ Using Tapatalk

03-01-2017, 07:30 PM	#7
KAT-PWR Nissanaholic! Join Date: Dec 2011 Location: US Posts: 2,040 Trader Rating: (11) Rides Gallery: KAT-PWR Feedback Score: 11 reviews	Check injector o rings as well. Common issue __________________ MRP Manufacturing

03-01-2017, 09:48 PM	#10
feito Nissanaholic! Join Date: May 2007 Location: Texas Posts: 1,999 Trader Rating: (1) Feedback Score: 1 reviews	^lol __________________ Tuners are big bullies

03-01-2017, 04:31 PM	#2
rawgarage Banned from the Marketplace Join Date: Oct 2007 Location: h o u s t o n Age: 36 Posts: 5,986 Trader Rating: (75) Feedback Score: 75 reviews	that enthalpy tune?

03-01-2017, 04:39 PM	#3
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	What about it?

03-01-2017, 06:15 PM	#5
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Yes i just checked my ecu codes and im getting 21 and 34 for knock sensor and cas

03-01-2017, 07:43 PM	#8
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Got it thanks, will check it out tomorrow after work and give you guys an update

03-01-2017, 09:42 PM	#9
rawgarage Banned from the Marketplace Join Date: Oct 2007 Location: h o u s t o n Age: 36 Posts: 5,986 Trader Rating: (75) Feedback Score: 75 reviews	check it now damn it....fuck work...

03-02-2017, 05:37 AM	#11
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Got to go to work,lol.

03-02-2017, 09:21 AM	#12
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Found out one of my plugs in my knock sensor subharness doesnt lock into the the knock sensor, getting another knock sensor subharness. Hopefully it is just a connection that was coming loose causing my car to run rich at idle and causing me to get code 34 as well. Btw i have ls coilpacks and gonna go back to the stock coilpacks to see if this helps.

03-02-2017, 12:59 PM	#13
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Is the code because knock is being detected or is it a failure somewhere in the circuit

03-02-2017, 01:30 PM	#15
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	What rpm do you guys time your rb's? I hear people say 900 800 750 650? The fsm says 650 +/- 50 rpm

03-02-2017, 01:44 PM	#17
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	I honestly think its the maf where should i start at

03-02-2017, 05:06 PM	#18
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	What approach should i take to diagnose the issue?

03-02-2017, 09:49 PM	#19
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 42 Posts: 4,829 Trader Rating: (17) Feedback Score: 17 reviews	You check fuel pressure, pressurize the plumbing for leaks to 15psi~ check you are using the correct maf, make sure you have the right tune in the chip, fueling is basically maf -> ecu -> Injector so this is the entire chain of command I have suggested above. If it still runs rich at idle, dial it down using a SAFC type device, OR get somebody to re-tune the chip. Not all 700~CC injectors are identical, so a tiny change in the fuel map, engine idle vacuum, idle conditions, pulse dead-zone (delay) as voltage at the injector adjusts the delay and so forth, it is too many variables for a "canned tune" as you move up in injector size. In other words, the larger the injector, the more unknown the injector, the less likely you will be "in the correct region" at low injector pulse widths such as around idle.

03-02-2017, 10:05 PM	#20
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Fuel pressure is at 38 psi at idle, using n62 maf. I checked with my tuner about my setup and he said he tuned for the same setup. My problem only occurs on idle the closer the car comes to warming up the richer it gets until it reaches in the low 10afr range and it bounces between 10.9 and 10.3afr. Checked my tps and I am getting .46v closed throttle 4.16v wot maf is .4v ign on eng off and 1.2v eng on so both maf and tps are reading good. Checked to see if my injector o- rings are leaking and nothing as far as I can tell. I also swapped back to the factor coils and igniror setup and it didnt make a difference and the codes 21,34 returned

03-03-2017, 10:41 PM	#21
PaliRB Join Date: Feb 2017 Location: Ca Age: 37 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	UPDATESo today I found some interesting things. Pulled my cas and could barely turn it by hand, knowing at the very least the bearings are shot I borrowed a known working cas hooked it up, deleted the codes and with the ignition switch on engine off spun the cas by hand for a minute or two and checked the codes again and code 21 is gone so waiting to order a new cas and hopefully my issue will be resolved