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Discussion Starter #1
I just got the car with 125,000 miles on it (some of you might know from my previous post). Runs great, but I have no clue when the last time the plugs were done, so I might as well change them. What kind of plugs do you guys recommend? Im concerned with complete smoothness, if that helps. Also, should I leave them gapped at the setting at which I buy them, or go with a different gap (I have a muscle car too, so Im always changing the gap to get the most performance; not sure about caddies - if I should just leave the gap at whatever they come with)? Last of all, should I do spark plug wires as well, or leave mine in (and if so, wich should I go with)? Thanks again guys! By the way, how difficult is it to do the plugs on this 4.9? On my ls1 trans am its a complete bitch; Im hoping this is easier!
 

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2005 CTS-V, 1994 Infiniti Q45
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You'll wanna replace the plugs with ACdelco OEM plugs AND wires!!! Wires should be replaced every time....

I think they come pre-gapped, but im not certain on that......
 

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1968 Cadillac Sedan deVille, 1994 Chevrolet G20
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There SUPPOSED to be pre-gapped. Don't trust it though, they usually vary quite a bit.
 

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Discussion Starter #4
ok, cool; so what gap should I be looking for to get the most smoothness? Also, is it a pain to do these plugs?
 

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2005 CTS-V, 1994 Infiniti Q45
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I hear its no fun to do the plugs..... No fun at all, but it is doable...

Not sure on the gap, though....
 

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1968 Cadillac Sedan deVille, 1994 Chevrolet G20
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.060 for the 4.9. As far as ease, remember that the LS1 is RWD. Two sides to work on. 4.9 FWD. That rear bank isin't gonna be fun though.....
 

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Discussion Starter #7
another quick question; where can I get the ac delco plugs and wires? Do I have to order them, or do auto stores sell them?
 

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Bosch platiniums are the same smoothness. I was not that happy changing the 2 along the firewall on the pass. side. Just lift or flex the heater hose that runs back there and you'll get them. Some say it's better to go underneath, you can try that too/ Be prepared to swear and curse though. :D
 

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2005 CTS-V, 1994 Infiniti Q45
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And have some guaze ready, cuz youll have cuts and bruises on your hands.....
 

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90.5 Allante, 02 Deville, 13 ATS 2.0t
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RAMAIR57 said:
I just got the car with 125,000 miles on it (some of you might know from my previous post). Runs great, but I have no clue when the last time the plugs were done, so I might as well change them. What kind of plugs do you guys recommend? Im concerned with complete smoothness, if that helps. Also, should I leave them gapped at the setting at which I buy them, or go with a different gap (I have a muscle car too, so Im always changing the gap to get the most performance; not sure about caddies - if I should just leave the gap at whatever they come with)? Last of all, should I do spark plug wires as well, or leave mine in (and if so, wich should I go with)? Thanks again guys! By the way, how difficult is it to do the plugs on this 4.9? On my ls1 trans am its a complete bitch; Im hoping this is easier!
I just replaced the plugs, Autolites with 50K on them, in my 91 Deville with 169K. I selected the Bosch Platinum 2 plugs and picked up an honest 1.5 mpg. One year ago I replaced the Thermostate and in addition to getting more heat, I picked up 2 mpg. May I suggest using a anti sieze compoung on the plug threads. I was a little worrysome removing the old plugs, they came out hard.
Another helpfull hint if you want to enhance the Heating and cooling performance. I cleaned the evaporator, which was almost totally clogged. To gain access, I disconnected the battery, removed the maxi fuse and relay panel on the firewall. This operation provides acess to the control module for the blower speed. Removing this module givs access to the evaporator. I sprayed it with Simple Green, the hit it with a water hose.
What an incredible difference.

Blue_Eldo
 

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01 frontier , 89 Shelby CSX vnt
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on my 94 it was a pain in the arse to do the reay bank thats layed against the firewall , the only thing that was worse was the rear banks valve cover (did it last weeknd) , if you have done plugs on a full boat trans am this should be a cinch , that motor is way back there on the f body , i sugest a moving blanket draped over the engine and laying over it to get a good line of sight at the rear bank

i use ac delco rapid fire plugs
 
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