Missfire

[Foosblood24]

Hi, I'm new to the forum having recently purchased a 93 NA 5sp and you guys seemed very knowledgeable about stuff.

I'm experiencing a misfire in at least one cylinder. I've changed the plugs and one coil pack but the misfire is still occurring. I don't want to swap out the rest of the coils if I don't have to. Is there a way to test the coils to see if they're bad?

[Foosblood24]

Oh yea....and cup holders....any help on cup holders mucho apreciante'

[nissanfreak12]

Hi, I'm new to the forum having recently purchased a 93 NA 5sp and you guys seemed very knowledgeable about stuff.

I'm experiencing a misfire in at least one cylinder. I've changed the plugs and one coil pack but the misfire is still occurring. I don't want to swap out the rest of the coils if I don't have to. Is there a way to test the coils to see if they're bad?

Your misfire is more than likely injectors, you can always ohm test the injectors. Very easy, unplug each injector, test one at at time. A good injector will be in between 10-14 ohms. If it is out of that range, it is bad. You can also check by running the engine, pulling the coil pack one at a time. Which ever one doesn't change the engine tone or drops the idle is your issue cylinder.

Keep us posted.

[ThisIsSparTTa]

Swap spark plugs between cylinders. Swap coil packs between cylinders. Check for spark. Test injectors (as pointed out above). You have a 92, which means you likely have old style fuel injectors which are prone to fail due to ethanol. You can replace them 1 at a time as they go out, but you'll end up dumping more money into that than getting the new style, and just doing them once. http://z32.wikispaces.com/Fuel+Injector

[Foosblood24]

You have a 92, which means you likely have old style fuel injectors

No it's a 93 which does take a different injector but does that make a difference in fail rate or do the injectors fail for the same reason?

[Foosblood24]

Ok, these guys give a 2-year warranty and the prices speak for themselves. The Phase 2's are reman and the Phase 1's are new. They charge $8.00 per core so add $48 to the sale price, but it's refunded back to your card. I'm going to order 6 of the phase 2's on Saturday. I'll keep you updated on the progress.

http://www.injectorwarehouse.com/ShopBy ... ZX&mode=EG

[ThisIsSparTTa]

The NA's transitioned during the 93 year, you could have either. I dunno if I'd mess around with random injectors, but your call. Most people will only use Nissan/Nismo because other ones can have unpredictable flow rates and other issues. May not be as much of an issue on NAs though. If you are going from Phase 1 to 2, you will need an adapter kit like this as well: http://conceptzperformance.com/Cart/des ... .164.62.64

[Foosblood24]

Also, what exactly is the advantage of higher CC injectors. I've read on here and other places that my NA doesn't need them and the stock 270CC's are the strict way to go.

[RubyRed300ZX]

Beware: Those prices seem too low for new injectors. And, nowhere on the page does it state "New" or "re-manufactured." Additionally on Bostech's site under company history it states, "Stuckey Bros. Auto has two re manufacturing divisions: CV Unlimited and Bostech. The CV Unlimited division re manufactures CV axles and rack & pinions. The Bostech division does electric fuel injectors for gasoline and diesel fuel injectors." Not all that clear as to what the hell "division does electric fuel injectors" is supposed to mean. The cost of the labor to install the injectors (or your time to do so) isn't worth the savings for re-manufactured injectors. Typically, re-manufactured means they clean them, and replace the o-rings. Does nothing for the tired solenoids.

As for a cup holder on a 300ZX, that's what curvacious blondes are for when they're strapped into your passenger seat.

[ThisIsSparTTa]

Higher CC's give you more fuel flow when you're pushing the engine. Typically you wouldn't need them on an NA unless you're somehow magically flowing big power, which is tough and expensive.

[ZL8NING]

Subscribing.

I checked the date this time!

[Foosblood24]

Beware: Those prices seem too low for new injectors. And, nowhere on the page does it state "New" or "re-manufactured."

The cost of the labor to install the injectors (or your time to do so) isn't worth the savings for re-manufactured injectors. Typically, re-manufactured means they clean them, and replace the o-rings. Does nothing for the tired solenoids.

Advice taken and understood. The customer service rep did say the phase 2's were remans, and the phase 1's were new. Both have a 2 yr warranty but all the trouble it seems to take to do the phase 2's seems extensive. But if the phase 1's are new (and it's what I'm currently running in the first place) I'll have to go with that.

As for a cup holder on a 300ZX, that's what curvacious blondes are for when they're strapped into your passenger seat.

Her hand is usually already preoccupied with pretending to drive a "British-side" manual transmission.

[Foosblood24]

Another thing I've notices in surfing YouTube for injector replacement tutorials is that cylinder 4 seems to give the most trouble. Actually, I've looked at 5 or 6 different YouTube vids and they ALL had the one injector in cylinder 4 that was bad. Is there a common problem with cylinder 4 that causes the injector to fail or is this just a coincidence?

[z32loverboy]

Probably coincidence, ethanol eats away at the coating on the coil inside the injector which controls opening and closing and shorts it out. The old style has the fuel go past the coil, the new style does not. When you pull the intake plenum off to get at the injectors they're all right there and just pull out of the fuel rail, it's not real hard to get them out. The hard part is getting the intake off. It's a good time to delete the throttle body water pipes and re route the vacuum hoses to make it easier to get off in the future. I would suggest going a head with the new style injectors, AND paying for good ones. Especially with car parts you always get the quality you pay for, sometimes it doesn't matter but with most engine parts it does.

I saw a cool mod a year or so ago where there were cup holders mad into the interior piece that sits about tricep level behind the center console. I just buy bottles and throw em behind the seat belt buckle, they fit pretty well there and don't really go anywhere. +1 on the curvacious blondes lol

[Foosblood24]

Would the injectors from Autozone be reman or new? They don't give the info one way or another.

Also, is there a whole lot of complication to going from Phase 1's to Phase 2's? I've heard everything from a complete fuel rail swap to simply changing the electrical connectors to the 93 is interchangeable without any mod at all. Would love to know this before diving into a complete plenum removal and all that.

[nissanfreak12]

This is the best thing you can do. Just buying one injector will lead to frustration when another one goes out, and another one will go out.

http://twinturbo.net/nissan/300zx/forum ... n-Kit.html

You will know if you have the newer style injectors, the plugs will be oval and not squared. If you have the newer style, you will just need the injector, no adapters or plugs, unless your plugs are broken.

[Foosblood24]

Oh wow...for the 93 will the phase 1 and phase 2 injectors fit in the same rail or does that need to be swapped as well?

[nissanfreak12]

They fit in different rails, but if you have the older version, you just need an adapter. If you have the newer style, it will be just a drop in.

You can tell just by looking at the injector plugs themselves. That will tell you what style you have. Don't get the injectors from autozone, I would trust them at all. Check out the link I sent you earlier in the post from Bernie, or check out conceptZperformance.com, Z1performance.com, they usually have good deals as well.

[Foosblood24]

Hmm...according to the conceptZperformance site, their phase 2's fit in the 93 NA's as long as they aren't CV

AUS Injection 300ZX Fuel Injector (270cc), Non-Turbo 93-96(except 93 CV) - New

Would there be a way to check if mine was a CV or not using the VIN?

Also, does anyone know or have advise about this "dremmel-grind" procedure done to the plenum so it doesn't have to be removed?

[nissanfreak12]

Double post

[nissanfreak12]

CV means convertable.

Just go check the connectors, that is the best way to tell.

[Foosblood24]

CV means convertable.

Just go check the connectors, that is the best way to tell.

Ah...that's interesting. They actually made a different fuel injector based on the convertible top?

I'm gonna take a picture of the connector and post it on here. You said either oval or square so it should be pretty easy to tell. Of course the no-brainer is my hope that the phase 2's fit on both the fuel rail and the connector (usually I'm not that lucky)

But all this has prompted a different angle; what is the shelf-life of a phase 1 injector? I mean, my 93 has 150,000+ and I believe the injectors that are on it now are OEM and only one is faulty so far. While I'm sure more injectors will start to fail soon, I'm wondering if it's actually worth all the headache to go to phase 2's if the original phase 1's lasted at least this long? I realize that once I've gone through the process of replacing them with phase 2's I'll never have to worry about injector fail again, but I should get at least another 100K out of a set of new phase 1's.

Need some advise on this!

[nissanfreak12]

Phase 1 injectors fail due to the ethanol in the gas as stated earlier, not is going to change that. Buying more phase one is a waste of money and time, they may last a year or two if your lucky.

Phase two have a better spray pattern, can handle ethanol, and are the same price minus the install kit. I switched over to phase 2, much better idle, throttle response, and definitely a good peace of mind. Quit questioning it and get phase two, there has been multiple discussions about this topic.

[Foosblood24]

Phase two have a better spray pattern, can handle ethanol, and are the same price minus the install kit. I switched over to phase 2, much better idle, throttle response, and definitely a good peace of mind.

Lovin' that right there! Phase 2 it is!

Quit questioning it and get phase two, there has been multiple discussions about this topic.

Don't get me wrong, I'm just very analytical on stuff (drives my gf batsh*t too) I just like to explore all the options. I'm definitely taking your advice, believe me!

[nexus08]

Don't get me wrong, I'm just very analytical on stuff (drives my gf batsh*t too) I just like to explore all the options. I'm definitely taking your advice, believe me!

It is always good to ask questions. Nothing wrong at all.

I had not heard that the Phase 2 had better performance (other than the ethanol issue). That really helps with the sell.

[nissanfreak12]

Don't get me wrong, I'm just very analytical on stuff (drives my gf batsh*t too) I just like to explore all the options. I'm definitely taking your advice, believe me!

It is always good to ask questions. Nothing wrong at all.

I had not heard that the Phase 2 had better performance (other than the ethanol issue). That really helps with the sell.

Questions are always a good thing, that is how we all learn!

Phase 2 will not get you better performance, it will atomize better causing the better throttle response, more even burn, better idle, and more complete combustion. Just smother all around.

[Foosblood24]

[UPDATE]

Gong to perform the "Dremel Method" grinding excess metal from the plenum.

http://www.thumper300zx.com/z32/dremel/ ... method.htm

My biggest hope is that my particular '93 is the one that accepts both phase 1 and phase 2 as it will reduce the job to simply switching out injectors and maybe the oval to square plugs. I'm hoping for obvious reasons I won't need a new fuel rail as that will require a total removal of the plenum. But on the bright side, the one cylinder that is missing is the front left (when looking at the engine) and from what I'm to understand, that is the easiest of all of them to replace.

[ThisIsSparTTa]

You shouldn't require a new fuel rail in either case. The adapter kit works perfectly fine for adapting the new injector to the old fuel rail: http://conceptzperformance.com/Cart/des ... .164.62.64 . TBH, I don't know that the Dremel method is the best time saver. You're going to tear up some bits, and that damn plenum grind for #1 that you to do regardless was a b**** for me even with the plenum off. Also consider that the dremel method gets metal shavings everywhere.

I'd recommend a plenum pull with a water line bypass and EGR delete if you can get away with it where you live. They aren't that scary after the first time, and they can go really quick. You can also get happy and replace the intake valve cover gaskets while you're there as a cheap form of insurance against headaches in the future, they are easy and quick. I wouldn't recommend doing exhaust valve covers with engine in unless they're leaking. Total PITA.

[Foosblood24]

You shouldn't require a new fuel rail in either case. The adapter kit works perfectly fine for adapting the new injector to the old fuel rail: http://conceptzperformance.com/Cart/des ... .164.62.64 .

My thing is, I have an NA T-top. (Lord knows why there's a fuel injector difference between T-tops and convertibles...) but that's what I have. My biggest question is do I even need the adaptors for the phase 2's?

TBH, I don't know that the Dremel method is the best time saver. You're going to tear up some bits, and that damn plenum grind for #1 that you to do regardless was a b**** for me even with the plenum off. Also consider that the dremel method gets metal shavings everywhere.

I'd recommend a plenum pull with a water line bypass and EGR delete if you can get away with it where you live. They aren't that scary after the first time, and they can go really quick. You can also get happy and replace the intake valve cover gaskets while you're there as a cheap form of insurance against headaches in the future, they are easy and quick. I wouldn't recommend doing exhaust valve covers with engine in unless they're leaking. Total PITA.

What is a water line bypass? I'm guessing the EGR delete has to do with the chip?

[Foosblood24]

OK...now I'm a little stuck. I just called Customer Service at CONCEPTZ PERFORMANCE, and they verified that 93 hardtop NA's run phase 2's OEM!!!

But ummm.....my #1 cylinder is still missing...

He did go on to say that phase 2's do go bad, but just not as often. He also said something about checking the OHM's and that I might need to replace the wiring harness?

HELP!!!