Nissan 370Z Forum - View Single Post

xsamis · 11-04-2021, 04:42 AM

Hey guys i have a really wild issue going on.

i get the p0300 code when the engine is warm and i try to hold RPM. The motor will pulsate. Meaning the RPM's will go up and drop down within 700-1000 RPM. i logged it being weird but im not sure what to look for in the log.

I know p0300 is very generic but i have almost ruled out EVERYTHING. ill explain below my mods and whats done to the car.
Fully built motor, wiesco pistons, corrilo rods, ARP L19 studs, coated OEM bearings, ARP main stud kit.
Motor was built by some company but i lifted the heads so i rebuilt the motor myself following the FSM almost to a T except the clearances on the bearings and gaps on my piston rings.
Sparkplugs were also changed previously and gapped larger given im boosted (i talked to my tuner)

I took off the VVEL motors like an idiot and had to adjust them a total of 4 times to get them within spec. I have them at 5.5 degrees on both so i do not think its my timing. Also the timing was done by me, I've retimed the car before and it worked perfectly.

the car has been sitting for a few months with E85 but i added 93 (i have a flex fuel tune and sensor) and also added some fuel stabilizer. Its at about half a tank of this mix. (i think bad gas might be causing all my issues)

my Fuel pressure regulator stays at about 55-60 PSI when idling, when my car does the whole pulsing thing, the FPS does dip down and then dip back up with my cars RPM's. I checked for vacuum leaks/fuel leaks and found nothing.

also while idleing and the car does this pulsing, i have NO CODES. only when i try holding the rpm does it give me the P0300.

i have ID1050 injectors and a walbro 485 with the CJM return kit and billet top hat.

also when i hold idle my car doesn't hold idle very well. it dips and then comes back up, then MIL will start flashing.

ECUtek tune btw

11-04-2021, 04:42 AM	#1 (permalink)
xsamis Base Member Join Date: Sep 2017 Location: MI Posts: 82 Drives: 2011 nissan 370z Rep Power: 8	Built boosted engine idle/pulsing Hey guys i have a really wild issue going on. i get the p0300 code when the engine is warm and i try to hold RPM. The motor will pulsate. Meaning the RPM's will go up and drop down within 700-1000 RPM. i logged it being weird but im not sure what to look for in the log. I know p0300 is very generic but i have almost ruled out EVERYTHING. ill explain below my mods and whats done to the car. Fully built motor, wiesco pistons, corrilo rods, ARP L19 studs, coated OEM bearings, ARP main stud kit. Motor was built by some company but i lifted the heads so i rebuilt the motor myself following the FSM almost to a T except the clearances on the bearings and gaps on my piston rings. Sparkplugs were also changed previously and gapped larger given im boosted (i talked to my tuner) I took off the VVEL motors like an idiot and had to adjust them a total of 4 times to get them within spec. I have them at 5.5 degrees on both so i do not think its my timing. Also the timing was done by me, I've retimed the car before and it worked perfectly. the car has been sitting for a few months with E85 but i added 93 (i have a flex fuel tune and sensor) and also added some fuel stabilizer. Its at about half a tank of this mix. (i think bad gas might be causing all my issues) my Fuel pressure regulator stays at about 55-60 PSI when idling, when my car does the whole pulsing thing, the FPS does dip down and then dip back up with my cars RPM's. I checked for vacuum leaks/fuel leaks and found nothing. also while idleing and the car does this pulsing, i have NO CODES. only when i try holding the rpm does it give me the P0300. i have ID1050 injectors and a walbro 485 with the CJM return kit and billet top hat. also when i hold idle my car doesn't hold idle very well. it dips and then comes back up, then MIL will start flashing. ECUtek tune btw