Hello all. I just recently purchased a 87 Nissan 300ZX with the VG30D(E) in it. I know its the same as the 1st or 2nd gen engines (i think 2nd, not sure??) and i want to know if any of you have a write-up on how to do it. Or if you would be so kind and help with a few helpful words advice. Thanks a lot.

Peace

-Josh

 

well i think u mean u have a VG30E the DE didnt come out till 1990. but ur best bet is www.z31.com thats all i can think of

~mike

 

Remove the plug wires with a plug wire removal tool, don't just jerk them loose and damage the ends. Ford sells a tool for this cheap at their dealerships. There are other brands, too.

Ok, this is important, clean around the sparkplugs down in the deep ports in the head before you remove them. Dirt, sand, and other stuff like injector wiring clips get down in there and can fall into the cylinder if you don't, which could score the cylinder under operation and make it use oil. Scratch the crud loose with a long small screwdriver or probe. Blow the recess in the head out with compressed air. Use computer canned air if you have to as a substitute.

I usually have to remove the PCV valve to get the plug out under it.

There are a couple of places where the wiring harness grounds and harness guides are in the way a bit. Take the bolts that hold them to the intake plenum out and move them aside. Don't overtighten them when you put them back, they twist off easily. You can use some loc-tite to keep them in place if you want.

The factory wrench is a long metal tube with one end formed into a sparkplug-sized socket. It has two holes in the other end that you can put a phillips screwdriver through to turn it, if you do not have the rod that goes with it. If you do not have the factory wrench, to a junkyard and get one from another Maxima or a 300ZX.

Arrange the plugs you remove pushed into a chunk of styrofoam packaging from some sort of a carton. Push the end of the plug the wire was attached to into it, so that you see the ends that were installed into the cylinder. Arrange them in the order they fit into the engine. The condition of a given plug will then be easily referenced to the cylinder it came from. There are fixtures you can buy for this, but even a cardboard box will work.

You can tell a lot about the condition of each cylinder by the coloration and condition of the spark plugs. There are charts with photos of plug conditions to compare them to available in most auto repair manuals. Reading plugs is an art, Jack Roush, the owner of several Winston Cup racing teams, is a well-known master plug reader. The basics are in the manuals, a consult with Jack will probably be expensive. You can tell if there is oil or fuel fouling and whether the fuel/air mix and spark intensity are optimal or not.

Use NGK plugs. Repeat, use NGK plugs. NGK BCPR6ES-11 or equivalent. Don't use Bosch plugs, my Maximas don't run well with them. I have taken new ones back out after a few minutes. Make sure they are gapped properly. Use a wire or feeler gauge type gap tool not that disc with the graduated edge. Gap is 0.039 to 0.043. Bend the electrode out or in to the desired gap. Make it even side-to-side.

Inspect each new plug for cracks in the porcelain insulator and other defects before installation.

When you put in the new plugs, use a stiff fairly straight piece of old air hose about 8-9 inches long to put over the end (where the plug wire will go on) to put the plug down into the threads with. It will let you turn the plug without damaging or cross-threading the opening, and you can tighten it by hand until it gets fairly tight. Old thick stiff hose works best. You can turn it counterclockwise and clockwise until you have gently engaged the threads in the head. These heads are aluminum. Don't force the threads and don't start the plugs with a wrench.

Tighten the plug about a quarter turn past hand tight. Don't over-tighen them. 14-22 ft. lbs. of torque, if you have a torque wrench. You can use the factory wrench or a plug socket on an extension with a torque wrench. You may want to use some hi-temperature anti-seize compound to prevent electrolysis between the dissimilar type metals (steel and aluminum) from making a corrosive bond that makes the plugs hard to remove.

Replace the wires, which are numbered with the proper number of the cylinder on them (factory wires). Listen for the little click into place. You can feel it snap into place, if you don't they aren't fully in place and you will cause a miss. The cylinder without the distributor on it has the number one plug in its front-most cylinder. The middle one is number 3 and the rear one is number 5. The other cylinder head with the distributor on it has 2,4,6, respectively, from the front to back.

Inspect the wires for grease, oil, or cracking. Replace cracked ones and clean oily ones with dish detergent. They need to be clean and dry. You can see bad wires transmit the spark down their outside in the dark. You can test wires and hunt misses by disconnecting the wires. One that wasn't working will not change the way the car runs when removed. A working one will change the way it runs for the worse. Factory wires are not really more expensive than good aftermarket wires if purchased at Nissanpartscc.com or Courtesynissan.com., especially if you mention Z31.com website. They are very good 9mm wires, and most aftermarktet wires are 7mm.

Factory caps have the appropriate numbers on them, if you are working with an engine that has aftermarket wires. Use a factory cap and rotor, if at all possible. Echlin parts at NAPA are a pretty good substitute, which are their more expensive line of electrical parts. Don't use cheap aftermarket stuff, they ususally don't fit right, and I have taken them back because the Maxima runs badly with them. Change the cap and rotor when you change plugs, only more often if you are seeing corrosion from condensation. You can see the metals transferring from the electrode in the rotor's end to the electrodes in the cap after it has run a while. Replace it when it looks bad or runs badly. Inspect very closely for cracks or thin grey trace lines where spark has been arcing.

That, ladies and gentlemen, is plugs 101 according to Dr.Disc. Reading plugs, comparison with the color charts, heat ranges, and tuning to get proper coloration comes in a more advanced exposition.

 

I run nothing but Bosch platinums in my z31 and in my 92 maxima. The maxima has 189k on it, and it's never had anything done but timing belt and battery. The car idles perfectly and works well in all rpm ranges.

 

We have this friendly disagreement on Z31.com too. My VG30E motors (normally-aspirated) run terrible on them. What coil are you running? I have a set that only was in my first 85 Maxima a few minutes before I took them out. It had a ultra-low mileage 84 Z31 engine in it (2700 actual miles when I installed it). When I got the recall done on that Maxima, I had Splitfires in it, and the Nissan tech could not get it to idle without missing. He said use NGKs only. I did get better highway mileage and more spunk with the splitfires, but they took higher octane fuel (92) to run well. Without any other changes, the NGKs cleared that up and let it run 87 octane without pinging. The next set were the Bosch platinums and they sucked really bad. The car was not drivable. I got some NGKs, by driving another car to the parts store, to replace them and had very fine results until I rolled the car with about 40K miles on the motor. Of course, I still have that motor awaiting a cherry chassis and I have the 2700 mile Z31 transmission in reserve, too. Maybe your heavily modified turbo Z31 has characteristics that allow their use without any problem. Your Maxima is a different generation than the 85.

 

I used Bosch platinums when my engine was stock in the Z. I also used them with 12psi and nitrous. I then upgraded to MSD ignition and coil, still with the Platinums.

I also use them in my Maxima that is 100% stock.

 

I only use AC Rapid Fire plugs in my cars. The ones that still have cap and rotor I try to get Standard Blue Streak components. Also use Standard Wire sets where available. I have never had trouble with them in any application from Cadillac 472 to Triumph 1500 and also good results with the Max's L28E. Just my .02

 

Nice. But you see, we were discussing VG30E engines. (The fellow's 89 300ZX has one in his car, too, unless somebody swapped something else in.) Your inline six is something else, and not comparable. I use AC plugs in my 81 Cutlass, and Motorcraft plugs in my Crown Vic, and they are recommended by their respective manufacturers.

The Nissan dealership techs I know in several area towns all recommend NGKs and factory caps and rotors for the VG30Es, and my experience, having tried other stuff, is they are right in doing so. I got my first one in 1984, and I have four VG30E powered vehicles at present, and three engines on the shelf in the garage as well.

I like Splitfires in my Suzuki bikes and in my Yamaha funjet because they make them more perky. I get 500 more rpm out of the funjet (boat) with the Splitfires. I ran Splitfires in a Maxima, and it was faster and got better mileage, but it idled like a popcorn popper.

 

I'm just sharing what has worked well for me over the years in many very different vehicles. AC Rapidfires are not Splitfires. I tried those one time in the wife's twin cam Saturn and didn't care for them overall. As for the other ignition components, cap, rotor, points, (where applicable) and wires, the Standard line is the best I have found for the price.
Maybe there's something unique about the VG30E that makes it unlike any other internal combustion engine that I may have missed? I would infer that a product that performs exceptionally well in such a wide range of applications as I have used it in, Cadillac high compression BB, a wide range of SB Chevys, Carbed and injected small Chevy 6 (including the 24V), DOHC Saturn, Austin Healy A-series, MG 18V (AKA Healy B-series), Triumph small 4 and Datsun L I fail to see why the VG30E would be an exception. If I am missing something, please fill me in. And, no I'm not being sarcastic or defensive. I really would like to know.

 

Quite honestly, its all preferences. Everyone has a certain brand they prefer. I usually base my preference on the car I drive. On my max I use NGK religiously, on my ford ranger, I used autolites, and on my mercedes I used bosch. On my dad's car I would probably put bosch on it. It also based on experience. I know many people who put bosch plugs in thier max and had success, I also know people who did the same thing and it all went bad real quick. If something works for you, by all means keep using it, because it works. BTW, the 89 300ZX has the VG30DE motor, not the VG30E. They just came out with the z32 that year.

S

 

89 300ZR, based on a Z31 chassis, which was not imported to the US, and which is not a 300ZX, did come with a VG30DET. But the 1989 300ZX cars were equipped with the VG30E and VG30ET. There were about 4000 built. These were Z31 series cars. 1990 Z32s, some of which were manufactured in 1989, did come with VG30DEs, like some 1984 Z31s were manufactured in late 1983. Your post is a bit misleading.

 

I use nothing but the best. NGK all the way. These are the best Spark plugs to use for our cars. I currently have the V-power NGKs.

 

Dude, I'm trying to butt heads with you, this is from what I learned about in the US market. If its wrong go ahead note that, as its not my intension to misled people. I never knew a 300ZR existed. Where was it availble? Japan, Australia, or both?

S

 

ur rite sarin there was a 300ZR that was in 86' and it had a basically it was a VG30DET, i read ur post and took a bit of time time research it as for where it was introduced i have no clue but from wut i found it was in japan im still lookin for more info
heres a link to where i found my info
http://www.j-garage.com/2210.htm

~mike

 

Look, this is just a friendly discussion for us to enjoy. Nobody is counting coup. The 300ZR and, get this, a 200ZR, were Japanese-market versions of the Z31 bodied cars, with engines other than the VG30E and ET offered in the 300ZX. There are Japanese-language websites with pics of them. I did actually see an 89 300ZX, Z31 chassis, at a car wash last night, it was a normally-aspirated VG30E automatic, silver-colored and very slick. It looked just like the 87 and 88 na versions to me. I own an 87 Z31 na coupe, an 84 na slicktop coupe, an 87 200SX SE V6 (S12VG30E), an 85 Maxima, and have most of two dismantled 84 Z31s and a dismantled 85 Maxima (less the chassis). I also have a 62 Chevy Impala Sport Coupe and an 81 Cutlass Calais Coupe.

 

Would you consider selling one of those VG30's you say you have on the shelf? And if, for how much?

 

$400 plus shipping for an 87 Maxima VG30E in good running conditon. You should install a timing belt on it, as the mileage and service history is unknown. I can get others, even extremely low mileage ones (one under 3K miles), but they are expensive. All are nonturbo, the high-dollar ones have known provenance, and are destined to go into my cars when needed, if not sold. I have some on the shelf, and I have some spotted that I can buy. I also have some single cam engines out of 3rd generation Maximas spotted. Maybe we should start another thread about available engines.