is this a hard job to do at home?

Look at the FSM and the threads in Infiniti Online Mechanic.

Accurate torque wrench highly recommended, especially if you don't torque steel bolts into aluminum recievers regularly.

Its mostly tedious -- removing the plastic covers, then the coil packs. There's a bunch of tiny screws.

thanks!

like jesda said its not hard, you just have to pay attention to whats going on.. its no biggie and ive done it twice.

Is their a code light when a coil goes bad? 90 q45

Recommend using a allen socket to make job easier! Also when removing coil pack wires remove ground from valve cover to head and move to a safe area. It's cold where I live so I put wires in a warm area because the colder they get the more brittle they get and when you go to put them back on they are as stiff as a dead man! The coil pack has 6= 5/16 bolts holding CP and bracket in place but, just remove outer left and outer right side bolts and remove coil pack and bracket as a unit. Make sure plugs are gaped correctly even though they come pre-gaped. Also apply a little plug lube to threads of plugs to prevent seizing and always start plugs by hand to prevent cross threading. Foot long piece of 5/16 hose attached to plug will get job done. Then finish with your socket.Most people forget but this is the best time to check all 8 coils for wear and damage. The contact surfaces where the spark is generated will be dome shaped and from mis-firing the tips of contact will be chipped or damage apply little Di-Electric grease to contact surfaces and too coil harness connector. Also when replacing sparkplugs always remove and replace one at a time because if you drop something down into the plug hole and it goes threw the hole there's no getting it out. If factory engine use factory NGK plugs but, if you have performance up grades you can up grade to iridium XI plugs which have a 100,000 mile warranty even if they don't last a 100,000 miles. People say stick to the factory plugs but, I know from experience that other plugs work without performance lost or damage! As an engine gets older you get cylinder blowby which means the plugs catch more oil blow-by which shortens it's life. An up-graded plug burns more which extends your engines performance. I know that I'm not the only one who has had success with other than OEM Plugs!

PopPop wrote: 1.) The coil pack has 6= 5/16 bolts holding CP and bracket in place

2.) People say stick to the factory plugs but, I know from experience that other plugs work without performance lost or damage!

3.) As an engine gets older you get cylinder blowby which means the plugs catch more oil blow-by which shortens it's life. An up-graded plug burns more which extends your engines performance.

4.) I know that I'm not the only one who has had success with other than OEM Plugs!

1.) Funny, my engine is metric, not SAE.

2.) Unfortunately we on the board have documented proof of Bosch and Autolite failing and taking out the engine. Others do indeed have performance loss.

3.) If there is that much blow by in a VH45DE, the engine is abused. The rest of the statement is pure bull caca. "An up-graded plug burns more which extends your engines performance." WTF does that mean and where is the data?

4.) Can you name anyone on this board who has been around at least a couple of years? Didn't think so. Anything less than 40K miles doesn't count. Any plug will last for a while.

maxnix wrote:1.) Funny, my engine is metric, not SAE.

2.) Unfortunately we on the board have documented proof of Bosch and Autolite failing and taking out the engine. Others do indeed have performance loss.

3.) If there is that much blow by in a VH45DE, the engine is abused. The rest of the statement is pure bull caca. "An up-graded plug burns more which extends your engines performance." WTF does that mean and where is the data?

4.) Can you name anyone on this board who has been around at least a couple of years? Didn't think so. Anything less than 40K miles doesn't count. Any plug will last for a while.

Mr expert I guess your right about one thing. Your engine being metric not SAE (Standard) right! I guess you can't put a standard tool on metric bolts without stripping it? Only a dumb M.F.B. would think like that. In Q45.ORG Wes evens says 5/8 inch socket will work in place of 16mm. I don't hear your mouth about that. Show me where the F'''k I said that NGK's don't work! NGK makes iridium plugs also right or wrong! Bosch or autolite didn't come out of my mouth! Do a true compression test on your engine if you know how and I'll bet that all 8 cylinders will not test out at factory specs.! Which means lost compression. Have you ever heard of a fouled plug and what causes it! I guess platinum and iridium are the same material right. Son your just afraid of change! Don't need to name anyone that has been on the board for a couple of years and if they all were like you there wouldn't be a board! I have own G50's 90-94 off and on ever since the early 90's and have wrenched on them to with the best of them! Using metric and standard tools. I worked on the import racing circuit since 1993 off and on so I'm not new to this mechanic S''t! Denso and NGK run neck and neck with the very similar Dyno readings! You can say what you want but, nothing beats hands on experience. Like I said before I know I'm not the only one who has run plugs other than OEM with success! God bless you!

Wow, with an attitude and closing incantation like that, it kind of speaks for itself, if we use the term "speak" in its broadest sense.

Your documentation is very impressive!

Been a little while since I dropped in here, looks like things have got a bit fiesty! I tried bosch plugs first (when I installed the engine, before I knew about NICO) and it ran like crap. Not saying you won't find a set every once in awhile that work, but for the work involved in changing them (not too bad, but no fun) I wouldn't think of using anything but NGK's. Wes, can you still hook him up with plugs cheap?