A17Z

iTrader: (1)

I think it was around 5000rpms when it started to cut out on me.

350Zzzz

You know, I thought that I felt that, but it was so minimal that I was unsure if I was imagining it. It seems to be fine when I switch gears.

If I change the coils now, it won't be covered under warranty, as the detectable coil failure has not yet occurred.

Thanks

G

McDan

Copper plugs don't last long. On my old Supra I could only get about 4000 miles on a set before the car started misfiring under heavy acceleration. Could be you just need new plugs.

Dan

350Zzzz

This is what I came up with from the NGK website

• A spark plug is said to have misfired when enough voltage has not been delivered to light off all fuel present in the combustion chamber at the proper moment of the power stroke (a few degrees before top dead center)
• A spark plug can deliver a weak spark (or no spark at all) for a variety of reasons...defective coil, too much compression with incorrect
  plug gap, dry fouled or wet fouled spark plugs, insufficient ignition timing, etc.
• Slight misfires can cause a loss of performance for obvious reasons (if fuel is not lit, no energy is be-ing created)
• Severe misfires will cause poor fuel economy, poor driveability, and can lead to engine damage

ProCharger recommends : Part # LFR6A-11, which is with a copper core.

Is there a reason a copper core spark plug is recommended versus the Platinums?

Standard type spark plugs are PLFR5A-11, but I was given PFR6G11 by Nissan. Does that mean it is one step colder?

Does anyone know the difference between the PLFR/A (PLFR5A-11) and the PFR/G (PFR6G11)?

Happy Thanksgiving!

Thanks
Gerald

350Zzzz

Apparently the PLFR5A-11, which are the standard, are long reach spark plugs; therefore one range colder would be the PLFR6A-11

As for the PFR6G11 that Nissan Parts gave me, turns out to be the short reach spark plugs. Thank goodness I only have 3 installed, as the difference in the alpha numeric coding between the 2 spark plugs did not sit right with me.

Now none of the Nissans dealerships that I contacted carry the PLFR6A-11.

The problem with the misfire seems to be narrowing down to the spark plugs, as the plugs were replaced with hotter plugs at the last service. I can only assume that the mistake occurred due to the fact that NGK has the heat range coded in reverse.

Phew.....thank goodness I caught the discrepancy before any major disasters occurred. But what a pain, replacing the spark plugs.

Will only know if the plugs are the culprit when I get the PLFR6A-11.

Finally, if someone can enlighten me as to why ProCharger recommends copper tipped spark plugs instead of Platinums or Iridium; and being that the narrowest gap for the Platinum are recommended at 0.039, should the ProCharged Platinums be gaped at 0.035

For the moment, I am gapping mine Platinums at 0.040

Thanks
Gerald

350Zzzz

Just received a call from my buddy at Triple J Auto Supply, they got the NGK PLFR6A-11 in for me; and I just spoke to them at 10:00 am this morning.

Now we're back in business

G

MySunset350Z

iTrader: (23)

ive had the ngk 1 degree colder coppers (lfr6a-11) on for about 2months / 2500 miles now. does ngk make 2 degrees colder in copper or just irridium?

350Zzzz

As it turns out, it was the spark plugs that were the cause of the multi cylinder misfire. It is back to normal with the new NGK PLFR6A-11, will take it for a spin tomorrow morning.

Thanks
Gerald

jeff

Glad to hear it was only your plugs.

Jeff

350Zzzz

Thanks for all the tips and advice.

The fouled state of the spark plugs when I pulled them out, no wonder they were misfiring. I am carefully scrutinizing the spark plugs to get a picture of the inside of my engine. First off, it does appear that the engine is running rich and possibly even excessive idling due to NYC traffic And, the clean threads, the first couple of threads closest to the tip does indicate that the plugs were running hot. Got to get me a magnifying glass to get inside the buggers. Overall, there were no signs of major internal issues.

BTW, I noticed at meets that quite a lot of the drivers warm up the engine by prolong idling; personally I would suggest driving off after 2/3 mins or even after about 10 seconds after starting your vehicle. Then drive it moderately for a few miles to get the engine and other components warmed up.

Warming up an engine by letting it idle can damage it.



Here is another view of the coils and ignition wire connectors.



Thanks Jeff, how's the Teins?

Happy motoring

G

jeff

Let's just say I found the low point on my car! But that's taken care of...

done12many2

iTrader: (33)

How hard was it to change out the plugs?

350Zzzz

At first glance, it appears to be a hell of a job best left to the pros. But, once you get going it becomes a breeze. I started by focusing on the not so difficult side first; the three cylinders on the passenger side.

You will need to remove the strut bar and engine cover before you you’ll have easy excess to the coils and spark plugs.

I then scanned the area and noted the various obstructions in the way of the 3 ignition coils; had to disconnect 2 hoses and a bracket; unhooked the ignition wire coupler connected to the coils by applying pressure to the locking clip and pulling it out.

Carefully removing the screws, holding down the ignition coils, making sure not to drop them into the engine. I found that using a cylindrical magnet with an extendable handle did the trick; Pulled out the coils.

You will see the head of the spark plugs recessed in a cylindrical cavity socket guide. Most ratchet sets comes with a 5/8 spark plug drive socket with a rubber grip in the socket, for holding on to the spark plugs (some sockets come with a magnet).

I removed the coils and spark plugs from each chamber one at a time; gap and install the new plugs. This helps one replace and reconnect each component back in its proper order.

Removing the set of 3 spark plugs from the driver side required removal of the intake air duct from the electric throttle control actuator to the duct with the mass air flow sensor; in order to gain access to the spark plugs. Again I had had to remove a wire holder bracket and replicated the process for the previous 3 spark plugs.

I’ve noticed that all Nissan service centers that I’ve been to, removing the upper intake manifold collector to access the sparks, but I was able to gain access to all 6 sparks without removing the manifold.

Also note that when tightening the spark plugs, do not over tighten, as soon as you reach hand tightness, give it another half to three quarter turn. In my case I chose to clean out the spark park threads

Hope this helps.

G

zland

350Zzzz:

I am trying to pm you but your mailbox is full.

Jeff - zland

350Zzzz

Cleared.........Sorry

G

daking350

I replaced my plugs with the nissan ones that were one step cooler than stock, a while ago when I was running n2o and I still get a little burp at idle..maybee i need the NGK too...

350Zzzz

The 350Z stock spark plugs are NGK(s); If the spark plugs you replaced with were in good condition and with the correct gap, then there may be a possibility that your coils could be defective.

I plan to switch to the ATI recommended copper plugs by spring 2004.

G

daking350

well does anyone know how much new coils are?or if there is an aftermarket company making them???

350Zzzz

The stock coils are fine and they cost about $500; does your car misfire at high speed or does the problem occur only at idle? In most cases, if the coils are bad, you will experience loss of power and high speed misses.

If your car is also misfiring at high RPM then I would suggest getting the warranty to cover the coils.

G

daking350

So have we go a def answer on the gap to be used on the NGK LFR6A-11's???