Dreaded P0300

v8Destroya · 04-26-2020, 10:15 PM

Hi guys looking for some solid advice. Been trying to fix this code for awhile now and seems to go away then come back. Replaced all spark plugs about 2 months ago. Upgraded to GTR injectors this month and currently in the process of gettting tuned by Moncef over at Admintuning. The car finally gave me a p0306 code after I cleaned my throttle bodies today. I checked the coil pack to see if it was a bad coil pack. I unplugged it and it didnt seems to make a difference in the overall idle. I figured to myself finally i found the source of my p0300 code. So i switched the coilpack 1 with 6 to confirm my thoughts. When unpluggin coilpack 1 the one i thought was bad once again no difference. So yay right? bad coilpack but heres the twist i went back to plug 6 and unplugged it and same thing not much of a difference in idle at all. Seems that im running around in circles here. Ive cleaned the maf sensors and dont have any other codes popping up. Very frustrating but the car is obviously having issues. When coming to a stop the car wants to bog out and die then idle returns back to normal range. Any one have an idea of where to troubleshoot further

v8Destroya · 04-26-2020, 10:17 PM

Just purchase a single coil pack to see if i replace the cylinder 6 pack if it will make a difference. :0 also car is at 81k miles currently

SteveSAS · 04-27-2020, 05:28 AM

better than having P0COVID

POS VETT · 04-27-2020, 06:32 AM

In a 6cyl, whether it's one or two dead cylinders, it's hard to tell. I would check continuity on the suspected coil.

SteveSAS · 04-27-2020, 07:24 AM

Just swap the coil packs around, clear code and see which code comes back. Could be simply you damaged one of the coil packs when you were doing the plugs. Or even a bad new plug as well.

JARblue · 04-27-2020, 07:56 AM

Quote:

Originally Posted by v8Destroya

gettting tuned by Moncef over at Admintuning.

ihaveashihtzu · 04-28-2020, 09:37 PM

compression test it and switch tuners heh

SonicVQ · 04-29-2020, 09:27 AM

You might want to check the fuel pressure. I have seen a few P0300 that were a result of a weak fuel pump.

On older cars, this was easy... However since Nissan/Infiniti moved to a return-less fuel system it requires a special tool.

You can pay someone to do this, or buy a "fuel tap" and 60 or 100 PSI gauge.
This is the one I use: https://cj-motorsports.com/products/fuel-tap-npt-2-bolt.

What ever you decide to do, the fuel pressure should be 50-51 psi at idle.

Tractionless · 05-09-2020, 02:35 PM

Need to check the ohm reading of each coil pack when off of the car vs what the value is in the manual to correctly diagnose a bad unit.

04-26-2020, 10:15 PM	#1 (permalink)
v8Destroya Base Member Join Date: Nov 2018 Location: chico Posts: 22 Drives: 2009 370z Manual Rep Power: 7	Dreaded P0300 Hi guys looking for some solid advice. Been trying to fix this code for awhile now and seems to go away then come back. Replaced all spark plugs about 2 months ago. Upgraded to GTR injectors this month and currently in the process of gettting tuned by Moncef over at Admintuning. The car finally gave me a p0306 code after I cleaned my throttle bodies today. I checked the coil pack to see if it was a bad coil pack. I unplugged it and it didnt seems to make a difference in the overall idle. I figured to myself finally i found the source of my p0300 code. So i switched the coilpack 1 with 6 to confirm my thoughts. When unpluggin coilpack 1 the one i thought was bad once again no difference. So yay right? bad coilpack but heres the twist i went back to plug 6 and unplugged it and same thing not much of a difference in idle at all. Seems that im running around in circles here. Ive cleaned the maf sensors and dont have any other codes popping up. Very frustrating but the car is obviously having issues. When coming to a stop the car wants to bog out and die then idle returns back to normal range. Any one have an idea of where to troubleshoot further

04-27-2020, 05:28 AM	#3 (permalink)
SteveSAS Base Member Join Date: Jun 2018 Location: Australia Posts: 61 Drives: 370z Rep Power: 5364	better than having P0COVID Jayhovah, Chrisc3, bunk and 2 others like this.

04-29-2020, 09:27 AM	#8 (permalink)
SonicVQ Base Member Join Date: Jan 2016 Location: Ontario Posts: 230 Drives: G37 Sport Rep Power: 6720	You might want to check the fuel pressure. I have seen a few P0300 that were a result of a weak fuel pump. On older cars, this was easy... However since Nissan/Infiniti moved to a return-less fuel system it requires a special tool. You can pay someone to do this, or buy a "fuel tap" and 60 or 100 PSI gauge. This is the one I use: https://cj-motorsports.com/products/fuel-tap-npt-2-bolt. What ever you decide to do, the fuel pressure should be 50-51 psi at idle. Tractionless likes this.

05-09-2020, 02:35 PM	#9 (permalink)
Tractionless A True Z Fanatic Join Date: Jan 2016 Location: Atlantic SE Posts: 1,326 Drives: '10 K23 ST 7AT Rep Power: 30525	Need to check the ohm reading of each coil pack when off of the car vs what the value is in the manual to correctly diagnose a bad unit. Felix 808 likes this. __________________ Toys Not Tots

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04-26-2020, 10:17 PM	#2 (permalink)
v8Destroya Base Member Join Date: Nov 2018 Location: chico Posts: 22 Drives: 2009 370z Manual Rep Power: 7	Just purchase a single coil pack to see if i replace the cylinder 6 pack if it will make a difference. :0 also car is at 81k miles currently

04-27-2020, 06:32 AM	#4 (permalink)
POS VETT Track Member Join Date: Apr 2015 Location: Columbus OH Posts: 612 Drives: Z34\|C4LT4\|C6Z06\|V25 Rep Power: 3366	In a 6cyl, whether it's one or two dead cylinders, it's hard to tell. I would check continuity on the suspected coil.

04-27-2020, 07:24 AM	#5 (permalink)
SteveSAS Base Member Join Date: Jun 2018 Location: Australia Posts: 61 Drives: 370z Rep Power: 5364	Just swap the coil packs around, clear code and see which code comes back. Could be simply you damaged one of the coil packs when you were doing the plugs. Or even a bad new plug as well.

04-28-2020, 09:37 PM	#7 (permalink)
ihaveashihtzu Base Member Join Date: Jun 2018 Location: Sacramento Posts: 33 Drives: 08 G35, 11 370 Nismo Rep Power: 45	compression test it and switch tuners heh