Murphy's law, Igniton trouble

[boznuttz]

What can go wrong will go wrong, and this is the exact case with my car. I finally got everything hooked up, and it's been such a PITA. It's a mild setup to start out with.

T3/T4OE 50 trim exhaust a/r 0.63stock injectorsFMIC setupstock MAF8:1 FMUetc etc......

I'm only running this setup at 0.25 bar( 3.6 or so psi) to begin with. and timing is spot on.

The car ran absolutely fine before I put anything on. But before I started up the car, I just grabbed a few random spark plugs and used them. The first three cylinders were Bosch Platinum +2 colder gapped plugs, and the forth was stock. When I started the car, it idled like sh*t. It was VERY rough and I had to keep feathering the throttle to keep it going. It smelled like some fuel wasn't burning off. The first cylinder plug was black, while the third looked very clean.

I am almost sure that the different gapped spark plugs could have caused my engine to run like crap, but I'm not totally sure. Can anyone verify if spark plugs could cause these symptoms?

[UNVMY240]

NO Nissan like Bosch plugs in them!!! Being a nissan tech for 7 yrs I have seen many cases where the backyard mechanic put these in a Nissan and almost instantly had cylinder misfires. Get NGKs please.

[boznuttz]

Lol, I have 3 NGKs.

The car ran a tad rough before being boosted, but still fine with a Bosch on the first cylinder and NGKs on the rest. This was before I changed the plugs. But can different plugs really make THAT much of a difference in which the engine will misfire and shake?!

[boznuttz]

Come to think of it, the Bosch plug that I pulled from the first cylinder was coated in carbon.

If I can remember correctly, this is pretty common when the gap is too cold.......but I'd still like to hear a few other opinions, lol.

[KA24Power]

spark plugs make all the difference, if they're not in the correct heat range for the application or are gapped improperly they can misfire like crap. Change them out for a good set of NKG's and see if you notice a difference.

[fourLUG_hero]

Can anybody verify this ? A couple days ago I just grabbed the most expensive Bosch plugs (iridium fusion) for my car and put them in my pocket. Are the regular NGK's better for my car ? I've heard good things but we didn't have them in stock. Gotta wait till friday then when the truck comes.

Autozone job FTW as well as FTL.

[boznuttz]

I'm guessing so. Should I get NGKs gapped at 0.044? It seems about the same as stock.

The more I google, the more common this actually seems to be as a problem pertaining to spark plugs with improper heat ranges. I'll take care of it first thing tomorrow.
Modified by boznuttz at 11:17 AM 1/17/2008

[Mauibuilt Guy]

Actually, I bought the Bosch +4's a while back and installed them and my car ran like ****. It misfired a lot. After that I always ran NGK's with a gap of 0.040 from the NIssan part#PFR6G-11 and never had a problem. Also the NGK's were like $11 a pop compared to the $5 for the +4's. You could also get the NGK's from Autozone, they should be fine as long as you can check the gap yourself.

I'm guessing so. Should I get NGKs gapped at 0.044? It seems about the same as stock.

I'm guessing so. Should I get NGKs gapped at 0.044? It seems about the same as stock.

The more I google, the more common this actually seems to be as a problem pertaining to spark plugs with improper heat ranges. I'll take care of it first thing tomorrow.

a .044 gap should be fine with low boost and you should run a colder plug whenever going for more boost.

Modified by boznuttz at 11:17 AM 1/17/2008

[scheffler]

Get NGK's get 2 heat ranges lower gap them to .038 and you can adjust the gap up or down to your cars likeing but .038 is a good starting point.

YES your plugs will make a big differance.You should put this up in the KA-T fourm vs gen chat.I have been running NGKs on my ka-t for the past 2 years they work great.

[boznuttz]

Ugh, the car doesn't just misfire, it's just completely undrivable. Can this really all be attributed to just the spark plugs? It won't idle properly at all. Not to mention the car won't even accelerate at all.

BTW, I'm stranded at my friend's house 160 miles from home, lol.
Modified by boznuttz at 7:51 PM 1/17/2008

[2kul]

just go buy a set of NGKs. i dont know why your going cheap on plugs. their like $1.50/plug. and check your vacuum lines.

[boriquaS13]

Did you check for for any intake leaks after mass air meter? Man it could be any number of things. I used the coldest ngk plugs I could find for my bluebird det and on stock ignition I had to gap them down to .028, after I installed my msd I was able to bring them back out to .035. This is all done on a disco potato turbo and 23lbs of boost.

[Shabbernigdo]

I currently have the bosch plat 4 prong plugs in my car and have had no problems at all. Other then the fact that 4 plugs cost 40 fkn dollars and really dont seem make much if any diff from the stockers. but eh u live u learn.

[krazydriver]

Ngk V-Power Bkr7e.. That oughta solve the plug problem.

[boznuttz]

All I seem to find around local shops are the NGK BKR5s with a gap of 0.044....Ugh.

[devil_child]

will it idle if not try the maf on the blow thru side instead of draw thru. check for leaks. and get some bkr7es or 5e's with a low gap and low boost.

[Licenthrope]

Sorry to but in. YES absolutly spark plugs make that much of a difference. Especially on 4 cylinder engines. but just to be on the safe side, check to make sure your firing order is'nt off a hair. i've done that once and yes crap is how it ran.

[sebazztard]

ive ran +4's for the past 6 years, never once had a problem with them. only difference i found is a quicker startup. maybe since its a ka-t application, temp is different? oem ngks are pretty cheap, its definatly worth a shot for the price.

[DougRoost]

The first three cylinders were Bosch Platinum +2 colder gapped plugs, and the forth was stock.

This comment makes no sense; gap is the distance between the center electrode and ground electrode(s), heat range is how fast the plug conducts heat away from the center to the cylinder head. The gap is a function of the power of the coil and ignition system (the more energy the bigger the gap can be), while the heat range is a mechanical property of the spark plug.

As others said, this really isn't worth the time to type. Put a matched set of the right plugs in and then work from there. All that money Nissan invested in the ignition becomes reality at the spark plug. If you have junk wires or plugs nothing happens. It's even worse in a boosted application since you have additional cylinder pressure the spark has to jump across the gap in.

[boznuttz]

This comment makes no sense

I meant that I wasn't using the same plugs, sorry it wasn't a little more clear.

The only issue that I'm pondering is that the car ran somewhat fine with the plugs in it now. It was a ***** and a half to start and would misfire somewhat, but since the car has been boosted, it idles like crap.

[e1_griego]

WTF are you doing running a 50 trim with stock fueling?! Ridiculous. What CAN go wrong WILL go wrong if you cheap out and don't do it right the first time. This is why people say KA-T is unreliable etc, because of all the half-assed setups floating around.

Get the BKR7E's, gap 'em to .028-.030. That's after you get some real, supporting fuel mods and some management of some sort.

Alex

[boznuttz]

On about 3 or 4 psi, the stock 270s are fine with an 8:1 FMU.

[e1_griego]

Sure. Get rid of that **** and get some real fuel/mgmt.

Alex

[boznuttz]

Lol, it's crude, but works.... and it'll get my car moving for now until I go with an SAFCII / Wideband combo.

[Morph]

Man when I saw the title I was thinking that he threw a rod across the yard but damn, just a misfire....I was hoping for so much more.

[CRyan]

Wow - I never knew Nissan engines didn't like the Bosch plugs. . .makes me now reconsider the platinum 2's i'm running now. . .

[Jookmasta]

holy ****ake............um ur using stock injectors and fmu which is ok for now but how the hell do u know what ur a/f's are across the board. alot of your driving issues could be due to the a/f's that you have.

also as said earlier, u need to get ngk plugs with 2 step colder heat range. gap them to .030 and go lower until your car is purring beautifully. they are only 7 bux for the four of em and if they are out of the BKR-7E, you can use BKR-6E for the time being.

on a side note, get an safc and some larger injectors asap.

[Riubens]

the problem you have doe snot sound like a spark plug problem your car is obviously running too rich check your maf sensor when the maf goes bad it has the same symptoms you described also check for leaks in the vacuum or intercooler piping also try starting the car with out the FMU ,trust me I've had the same prob as you and it was the MAF after I fixed it then I had a bad leak which cause my car to run like **** and barely idle.

hope that helps alittle. G/L

[fourLUG_hero]

Thanks alot guys. Tomorrow, I'm gonna grab me a set of NGK's from my job. Anybody wanna buy some ? I'll sell for 5 bucks for all 4.

[beatd]

Thanks alot guys. Tomorrow, I'm gonna grab me a set of NGK's from my job. Anybody wanna buy some ? I'll sell for 5 bucks for all 4.

ME ME ME!!!!