Hi,
My problem is strange. The car ran like a dream and with the full Amuse exhaust/headers sounded like a Ferrari. When I put the JWT clutch and lighten flywheel it revved like high end motorcycle. Then out of the blue just costing to the gym, my car began to bogggg and sound like **** when I stepped on it. However, starting it was instant like a charm. When idling, it would idle around 800 then every once in awhile drop to 500. Then smooth for a minute then drop again. Then on the way home from the gym the service engine light came on so since I never seen that come on ---I milked it home and parked it.

Then I pulled out the tester and got a PO302 meaning Miss fire on cylinder #2. I immediately pulled the coil pack on #2 and looked fine then I pulled the plug and it looked fine. Then I pulled the coli pack from #4 and swapped with Number #2 to test and see if symptoms would change to PO304. However, the service engine light did not come back until I revved it a few times after running in my driveway for about 5 minutes. Then when I put the tester on and cleared the tester the service engine light went out. Well, I was going to put some HKS 10w-50w oil in with hks filter and change the dif oil because it was due. (have a race dif in so it needs changed regularly or it starts making a clunking noise when heated)

Sooooo, I drove and had it changed. After changing oil, I started the car and the SERVICE ENGINE LIGHT came on and I put the tester on it and got the same READING PO302.

Thus, I would assume that since the new reading did not say PO304 cuz I swapped Coil Pack that it stayed PO302 that the coil pack must be good. (take note: after swapping the car sounded great but there sill was a miss fire but very small -- AND no knocking at all during this problem -- engine is very strong with only 25,000 miles on it. )

I believe I have NKG Platinum spark plugs -- this really is weird because I cant understand why the plug would go bad. My next step is to change the plugs and see if it fixes the problem.


NOW THE WEIRD STUFF - My oil pressure gauge now idles at about 50-60psi and when I REV the car it shoots up like a tac to 90-100psi. Then back to Idle at 50-60psi WHEREAS before it idled at about 35-40PSI and when hot drops to about 25psi. Before if I revved it maybe it would climb to 60 psi. REV between 4000-6000 on the tac.


When it rains it pours - Could the Oil sending unit crapped out too?

I have heard that intake manifold leaks can cause this too??? Is that True?
Has anyone experienced this?

I am not getting a reading from the tester for oil sending unit?

Could low compression in #2 cause this but I have a hard time thinking its low compression because the engine sound really powerful - just this annoying intermittent miss-fire. ------------any of course the slight bogging when you step on it!!!

Any ideas???????????????



Just for background on my 350Z - I have the following on it:
Nissan 350Z - 2005 - 25,000 miles on engine (first engine!!!)

Volk Racing Mag wheels TE 37 Time attack limited edition
Black with red pin stripe 19inch x 10.5 Bridgestone tires

Amuse Titan R1 exhaust with Amuse Titan mid pipe

Tomei V2 Headers and test pipes

Greddy Emanage Ecu

Apex N1 Coilover shocks

Tomei 2way LSD

Cusco front and rear anti roll bars

Stainless steel upgraded break lines and clutch line,
With ceramic brake pads

Nismo thermostat

Motordyne Plenium 5/16 Spacer

08 model upgardaed LED rear tail light

Bose oem radio 6 stack CD player

HKS airfilter

JC racing. camber, toe and adjustable traction arms

About 2 months ago I added:

JWT 350Z Clutch/lightened Flywheel Combo, 03-06

 

This is the 350Z

 

According to the engine fault code , you have a misfire between ccylinders 1 to 8 Sorry i can't be any more help than that.

 

Actually, its a 350z so V6 3.5 so 6 cylinders. Code PO300 means miss fire at any of the 6 cylinders. However, PO302 is specific - Miss Fire is Cylinder #2
so from passengers side Left to Right - Looking at the engine would be arranged as so:
5 - 6
3 - 4
1 - 2
so miss - Fire is on front - drivers side cylinder. So best way to check coil pack is to swap coil pack from #4 with #2 and see if error code changes to PO304 -----if it does not then next step is spark plug change. If it does change to PO304 then coil pack needs replaced. In the Philippines 1 coil pack is $116 dollars - ouch!