INCREDIBLE upper-rpm misfiring...

[85_305]

My 3100 is easy you unbolt the side mount wheel well bolts and the top inside bolt, then slide the motor forward, and re-tighten the top inside bolt and it holds the motor forward for you.

Use the AC Delco normal plugs. They are proven to work good and are cheap.

Well scratch that, I will just have my mechanic do it lol. But i'll be sure they are ac delco's. Thanks guys! I will let you know how the results turn out

[IsaacHayes]

Oh come on you gotta get your hands dirty sometime. You are on an engine enthusiast message board after all!

R44LTSM Is the AC Delco normal plug.

[85_305]

I've already had the "honor" of rebuilding the motor from my Z28, and it's taken me YEARS to come as far as doing my oil changes and TPS changes Some thing piss me off to much, so I just wanna avoid that stage all together lol.
But there is no better gap than factory for these plugs?

[IsaacHayes]

I'd leave the gap alone. I believe on the 3.1mpfi R44LTSM the gap is .045".

I don't know if you could run the R44LTSM6 that the 3100's run, they are the same plug but the gap is .060". The ignition is the same on the 3.1mpfi as the 3100 (ICM and coils) so I'd think it would be strong enough for that gap, but I don't know if it would run good or not.

Going to a larger gap gives you more spark area to burn fuel but too big and the spark becomes weak if your ignition can't supply enough spark. Smaller of a gap is only needed when you have super high compression or forced induction.

So I don't know you may be able to run the .06" 3100 plugs for a larger spark area and the stock DIS should be strong enough, but there may be other factors why the 3.1mpfi runs a smaller gap....

Anyone else have input?

[pontiac3100]

mines need the .060 gap while the 95 needs .045 and the 96 and up aww i forgot.

but in my 3100 i used regular ac's and she burned em' out within 3 weeks.
but now i use rapidfires.

to replae the rears on my 3100 i remove the coil pack which in turn makes it easier.

[IsaacHayes]

Why would a 95 3100 need the older smaller gapped plugs? They later switched to the plat and then iridiums in later year 3x00's for longer lasting as far as I know.

Yeah removing the coil pack does help. I've done that before.

[pontiac3100]

wait?! they used iridiums??

it's weird that they said that.
but i stuck with the .060gap.

and i'm starting to question if useing rapidfire was a good idea

[IsaacHayes]

Yes, go to acdelco.com and look up say a 2004 impala 3400. Iridium. PN 41-101. Funny if I look up the plug for my motor (R44LTSM6) it doesn't show any vehicles, but if you look it up with the picture thing it does show it. I wonder if they discontinued it? If I look up my vehicle now it shows platniums and another plug with part number "6" rapid fire but it's not got the modified tip (extends down further to ignite more gas) and is .045" gap... Huh? lol Sounds like that last one would be less efficient at burning fuel since it's got a smaller gap and doesn't reach as far into the cylinder.

I'll stick with my R44LTSM6 as that's what the owners manual calls for and the car runs superb on them.

http://www.acdelco.com/parts/sparkplugs/identification.jsp

Is also a good link to look at for decoding part #'s.

[IsaacHayes]

Ok did some work and found this out. According to acdelco for a 3.1mpfi (your sunbird) you should run the R44LTSM like I said or if you want platnium run the 41-805. Both plugs have .045" gap.

--
Now for us 3x00 guys it seems R44LTSM6 was the first plug available then they switched to platinum and now iridium for all 2002+ motors. Below is the years and what plug ac delco recommends which I think is just what was recommended for that year, and they must keep changing them slightly with each year. I don't know the differences between them, but they gotta be slightly better with the newer years. The last 2002+ iridiums are being used even in 2007 motors so apparently GM is happy with that design... I'd probably run those in my 3100 if they didn't cost so much. All plugs are .060" gap below.

1994-95...41-908 platinum
1996-00...41-940 platinum
2001........41-979 iridium
2002-07...41-101 iridium

Looks like the first year they came out with platinum and iridium they did some tweaking the year after. I would avoid the 1994-95 and 2001 years for that reason and go with a newer year. So for a 3x00 I'd say a safe bet for plugs is R44LTSM6 for normal, 41-940 for platinum, and 41-101 for iridium.

I'll try to read up and see if I can't decode the differences in those plugs and see what they changed.

[85_305]

Well thanks for the input all, as an update I installed Autolites into the front bank today, and will do the rest in the rear bank tomorrow. MAN were those plugs fucked! Man they are terrible!! The electrode is worn, the tip is fucked etc.. just terrible.

[IsaacHayes]

haha so did you do it yourself? Soon you'll have a smooth running motor!

[85_305]

Ya I did the front bank myself, and reconnected a rear-bank plug wire that was disconnected. The idiot at the mechanics place didn't reconnect the wire they replaced
So it runs good anyhow, I just have three more plugs to change today. And it's chilly and Buffalo Rainy today lol.

[IsaacHayes]

hahah gotta love when you take a car in for something to be fixed, and they replace it but don't hook it up. lol Just another reason to DIY!

So it doesn't missfire anymore I gather?

[85_305]

Ya I was pissed. Even moreso the fact that the plug wire was too short, so they just let it dangle there. Plus, they were gonna charge me 70$ 2 days later for new plugs

But ya she runs great now. I have to do the rear-bank plugs tomorrow. The fronts were TERRIBLE when I yanked them.