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Discussion Starter · #1 ·
i have been running ac delco 41-932 gapped at .060 and they seem to work ok, but i wasnt real happy with them. decided to go with 104's, gapped at .054 and it seems to run great the only problem is that when your sitting still in drive or neutrel the car has a slight miss that you can feel, ive scanned it and it will be random cylinders. the question is, should i gapped them down to .052 or gap the to .056. just need help on which direction to go with.

mods are: 3.4, ported front manifold, throttle body spacer, 2 1/2" downpipe, no ubend/resonator and 9" open cone K&N
 

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104's

I'm gapped at .050 on my '04 and I'd say I have the same issue...a very slight tremor at idle. If I put it in drive with my foot on the brake, it's not there. I'm not sure if it's from my plugs or from my MAF screen being removed. I'm going to try TR6's gapped at .056 this weekend. I'll let you know if that makes a difference.
 

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I have the 104's and gapped at .055. I don't seem to have that slight miss you describe. Have you checked or replaced the plug wires?
 

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I have TR-6's gapped @.056", and a descreened MAF in my 04', and it idles smooth as silk. ;)
 

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Discussion Starter · #9 ·
not sure really, im guess that the MAF just went bad being that the car has 104,000 on it. it is a 99, and actually im not even sure if the MAF is going to fix it. i have been told by many of people including a good friend of mine who is a gm certified tech that it is the MAF. i will be putting the new one on today and finding out
 

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Over the weekend I replaced my 104's with TR6's. I no longer have the tremor. Not sure if was the change for 104's to TR6's, or the change from a gap of .050 to.056, but all is good now.
 

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I recently changed to the TR6 plugs, but afterward I was experiencing misfire around 4k while in WOT mode. My idle is fine and the problem only happen during WOT or sudden throttle trump. The plugs were gapped at .052 when this happened. I pulled the plugs and regapped to .056 but the problem still happend. I pulled the TR6 and installed TR55 gapped @ ..057 but I am still having the same issue.
I must note that while I was changing the plugs I also cleaned my throttle body with carb cleaner-(aka MAF killer), and I also replaced a damaged throttle body gasket.
I am at a lost. My next move is to regap the TR55 to .55, but I doubt that that will change the WOT characteristics.
 

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How old are your plug wires? If you're like most, they are the stock original ones. I would highly recommend replacing them.
 

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SLEEPGTP said:
I recently changed to the TR6 plugs, but afterward I was experiencing misfire around 4k while in WOT mode. My idle is fine and the problem only happen during WOT or sudden throttle trump. The plugs were gapped at .052 when this happened. I pulled the plugs and regapped to .056 but the problem still happend.
Why did you gap them larger if you had misfire, wouldn't you need to close them instead?
 

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I agree with BlackZ34. I had the same issues when I had my cam installed. The garage replaced my AL103's and had them gapped at .54 :eek: This was way too big for my setup. You should have seen my dyno it was all over the place. During idle my car felt like it was going to shake apart. I took them out and gapped them down to .48(as Zoomer recommended for my setup) and the problem was fixed. I'd say try going in the other direction. Bigger causes more misfires, in most cases.
 

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I will certainly re-gap them lower and see what happens. Since I have the TR55's in now I will gap them to .055 as recommended and see what happen.

I am also tempted to put back in the TR6's and gap them lower than the .052 that I had them and see what the result is too.

What I have noticed is that more than one vendor will have different recommendation and I think that can be confusing. Of course, no two cars are set up the same but your plug requirement is based on the amount of boost or pulley size you have, not "supporting mods".

I am sure I will get kicked in the teeth for saying this :rolleyes:
 

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When I got my 00 PAU L67 I pulled the plug wires off the coil (I know this is a problem area on the previous 3800 LN3 I had) and sure enough, 4 out of 6 towers on the coils were rusted, badly. It had an idle miss that was very mild, but knowing the 3800 LN3, I knew it could be better.

I replaced coils and wires (wires were rusted up too) and it cleared 90% up, added in new plugs (TR5's) and it is nice.

I did however, notice that I had one wire with about 1.5" of insulation GONE. Mouse! Some critter was feasting on the #4 or #6 wire. I found a nice nest up there too under the nice vanity cover. Being the car is 8 years old and I bought it with 67K on it, it didn't get the wheels driven off of it, so it probably had a fair amount of time sitting in the garage.

Not helping things for good idling and power....

So inspections are worth it.
 

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wow..

i tried ngk tr6 plugs and my car misfired.. went to autolites and runs like a champ..
 

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It is so wierd these cars react so differently to different things and tweaks. I have noticed my car likes Autolites more than NGK's. I wish there was one way to go with a certain mod combination. It would be so easy. I guess it just depends on the variances in each motor and transmission and who put it together. It is like the frame on the 67 GTO my Dad and I are restoring. One side of the frame is welded immaculate and the other side looks like a kid done it.
I guess what I am saying is to try different combinations until you find out whats right for your car. I noticed a difference going from a gas that was not in the top tier group to one that was. The car ran noticeably smoother and the raise from 92 to 93 octane could not have hurt anything.
 

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I will try some 104's and see how it does, engine is stock, not modded, so are 104's too cold? I do live in a cold climate (well, right now I do! Probably won't be over 40F for the next 4 months....)

Can't hurt! I did use garden variety plain plug wires. I have the stockers still, I guess I could put them back on and see if I can get back the stone stock combo as I got it when I had no KR issues at all, even warm out. Stock plugs I still have, around 80K on them. I think I had KR with them too, but can't remember.
 
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