SR20DET Running Rich (Ongoing issue) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

AwhiteS13 · 10-10-2018, 09:51 AM

All,

Hoping to get some insight here and see if anyone has any possible solutions. To be frank I have checked everything...

I am on my second long block with all new sensors.
VAC leaks OK
Fuel injectors have been flow tested and checked for leaks.
Compression is good.
MAF has been replaced.
Fuel pressure doesn't hold after key off, so I replaced all hard lines in case of a leak, come to find this is typical with some walbro pumps
New FPR
Sensor voltages checked @ ECU. MAF, CAS, 02, TEMP, TPS, Knock
Spark Plugs changed
Air Filter changed
Coil Packs changed
Timing is @ 15 degrees, doesn't seem to fluctuate at all when idling.

I have a S13 redtop - running on an E5 Enthalpy tuned ECU, using a FAT 02 sensor. I have tried a skinny. I have had the ECU reflashed when swapping long blocks (old one had cams) and also sent it in to be checked by enthalpy since then and was told it was ok.

Stock SR
S15 Turbo
550 CC injectors

The issue is the car idles at 10-11 AFRs. Under a load it is Okay, typically 11-12 AFR. The issue does seem to be getting worse as now in higher gears it will pretty much peg 10 and begin to break up.

Another oddity is that when cruising it will find 13.6-14 afrs for about 15 seconds and then go full rich until I get off the throttle. It will lean out, if I get back into cruising throttle it will go back to 13.6-14 for a while again before dropping again.

I now have a Power FC and I am looking to re-tune with the feeling I have exhausted all other options but I am looking for any feedback on what else I can check. I wont be tuning it till spring so I'd like to ease my mind or troubleshoot further.

5280VertDET · 10-10-2018, 12:03 PM

Have you tried a known working FPR and gauge?

AwhiteS13 · 10-10-2018, 01:26 PM

I failed to mention I replaced my FPR. I had a Megan and now have a Tomei, it has a gauge. Fuel pressure is good.

Kingtal0n · 10-14-2018, 01:39 AM

sr20 is very simple. It goes

maf -> computer -> injectors

1. Disconnect the O2 sensor
2. verify maf and ecu are correct for application and the wiring is right
2.5 same goes for other basics i.e. fuel pressure, compression test, boost leak test (PRESSURE TEST DO NOT NEGLECT THIS)
3. Tune the engine properly

Rom tunes are great... Enthalpy is great... however rom tunes and enthalpy are not "all knowing"
they cannot account for myriad factors. It is up to you to fine tune the engine somehow, either by letting the rom tune in person ("real tuning") or by adjusting it afterwards via SAFC. In other words: Majority of rom tunes require SAFC for fine tuning.

10-10-2018, 09:51 AM	#1
AwhiteS13 Join Date: Mar 2006 Location: Iowa Posts: 33 Trader Rating: (0) Feedback Score: 0 reviews	SR20DET Running Rich (Ongoing issue) All, Hoping to get some insight here and see if anyone has any possible solutions. To be frank I have checked everything... I am on my second long block with all new sensors. VAC leaks OK Fuel injectors have been flow tested and checked for leaks. Compression is good. MAF has been replaced. Fuel pressure doesn't hold after key off, so I replaced all hard lines in case of a leak, come to find this is typical with some walbro pumps New FPR Sensor voltages checked @ ECU. MAF, CAS, 02, TEMP, TPS, Knock Spark Plugs changed Air Filter changed Coil Packs changed Timing is @ 15 degrees, doesn't seem to fluctuate at all when idling. I have a S13 redtop - running on an E5 Enthalpy tuned ECU, using a FAT 02 sensor. I have tried a skinny. I have had the ECU reflashed when swapping long blocks (old one had cams) and also sent it in to be checked by enthalpy since then and was told it was ok. Stock SR S15 Turbo 550 CC injectors The issue is the car idles at 10-11 AFRs. Under a load it is Okay, typically 11-12 AFR. The issue does seem to be getting worse as now in higher gears it will pretty much peg 10 and begin to break up. Another oddity is that when cruising it will find 13.6-14 afrs for about 15 seconds and then go full rich until I get off the throttle. It will lean out, if I get back into cruising throttle it will go back to 13.6-14 for a while again before dropping again. I now have a Power FC and I am looking to re-tune with the feeling I have exhausted all other options but I am looking for any feedback on what else I can check. I wont be tuning it till spring so I'd like to ease my mind or troubleshoot further. Last edited by AwhiteS13; 10-10-2018 at 01:26 PM..

10-10-2018, 12:03 PM	#2
5280VertDET Nissanaholic! Join Date: Aug 2013 Location: Denver Age: 40 Posts: 2,052 Trader Rating: (14) Feedback Score: 14 reviews	Have you tried a known working FPR and gauge? __________________ S13 Vert \| SR \| PE1420 \| 5-Speed \| 15x9.5 - 0 \|

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10-10-2018, 01:26 PM	#3
AwhiteS13 Join Date: Mar 2006 Location: Iowa Posts: 33 Trader Rating: (0) Feedback Score: 0 reviews	I failed to mention I replaced my FPR. I had a Megan and now have a Tomei, it has a gauge. Fuel pressure is good.

10-14-2018, 01:39 AM	#4
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 40 Posts: 4,828 Trader Rating: (17) Feedback Score: 17 reviews	sr20 is very simple. It goes maf -> computer -> injectors 1. Disconnect the O2 sensor 2. verify maf and ecu are correct for application and the wiring is right 2.5 same goes for other basics i.e. fuel pressure, compression test, boost leak test (PRESSURE TEST DO NOT NEGLECT THIS) 3. Tune the engine properly Rom tunes are great... Enthalpy is great... however rom tunes and enthalpy are not "all knowing" they cannot account for myriad factors. It is up to you to fine tune the engine somehow, either by letting the rom tune in person ("real tuning") or by adjusting it afterwards via SAFC. In other words: Majority of rom tunes require SAFC for fine tuning.