Nissan 370Z Forum - View Single Post

Jrod · 02-12-2019, 06:00 PM

09 370Z 69K miles

About 10 days ago on my way home I pulled off interstate and got $15 worth of gas at a gas station i dont usually attend. Right after I left and was on the on ramp to interstate it started to miss, on the rest of the way home, anytime I was driving up an incline it would also miss. I figured bad gas right away. The next morning I drove into town and put in a bottle of Iso-Heet and topped the car off with 93 octane from a reputable gas station. Problem persisted. It threw a code and I got it read and it was a P0301 (cyl 1 misfire), I changed all the plugs, all looked ok except cylinder 1 was caked with carbon, was not oily or anything. The problem got a better by a small margin but persisted. I added a bottle of seafoam to the tank to try to clean the injectors with no luck. So I pulled the fuel injectors and cleaned them. While doing this I also swapped the #1 injector out with the #2 cylinder in case I had not cleaned it properly the misfire should switch cylinders and I could identify the bad injector. I reset the code and after a little driving the CEL came back on and was still reading P0301. I then replaced the #1 ignition coil, no difference. Yesterday I pulled the ignition coil and plug so I could make sure it was getting spark. The plug I had replaced just a few days earlier was already caked with carbon. I replaced the plug and verified it is sparking correctly. The problem still persists. Im kinda lost at this point and could use any advice or direction as to where to look next. Thanks.

TLDR: Cyl 1 misfire, possible bad gas, replaced plug(heavy carbon deposits), added seafoam, cleaned injector, replaced coil pack, Replaced spark plug again(Heavy carbon deposits), dont know where to look next.

02-12-2019, 06:00 PM	#1 (permalink)
Jrod Base Member Join Date: Aug 2017 Location: NC Posts: 5 Drives: 09 370Z R 7AT Rep Power: 8	P0301 cannot find the cause 09 370Z 69K miles About 10 days ago on my way home I pulled off interstate and got $15 worth of gas at a gas station i dont usually attend. Right after I left and was on the on ramp to interstate it started to miss, on the rest of the way home, anytime I was driving up an incline it would also miss. I figured bad gas right away. The next morning I drove into town and put in a bottle of Iso-Heet and topped the car off with 93 octane from a reputable gas station. Problem persisted. It threw a code and I got it read and it was a P0301 (cyl 1 misfire), I changed all the plugs, all looked ok except cylinder 1 was caked with carbon, was not oily or anything. The problem got a better by a small margin but persisted. I added a bottle of seafoam to the tank to try to clean the injectors with no luck. So I pulled the fuel injectors and cleaned them. While doing this I also swapped the #1 injector out with the #2 cylinder in case I had not cleaned it properly the misfire should switch cylinders and I could identify the bad injector. I reset the code and after a little driving the CEL came back on and was still reading P0301. I then replaced the #1 ignition coil, no difference. Yesterday I pulled the ignition coil and plug so I could make sure it was getting spark. The plug I had replaced just a few days earlier was already caked with carbon. I replaced the plug and verified it is sparking correctly. The problem still persists. Im kinda lost at this point and could use any advice or direction as to where to look next. Thanks. TLDR: Cyl 1 misfire, possible bad gas, replaced plug(heavy carbon deposits), added seafoam, cleaned injector, replaced coil pack, Replaced spark plug again(Heavy carbon deposits), dont know where to look next.