Nissan Maxima Fuel Injector Change Tutorial

[CarAudioHelp]

I recently changed one of the fuel injectors in my car and I created a tutorial to go with it.

DIY 3rd Generation Nissan Maxima VG30E Fuel Injector Change

http://www.caraudiohelp.com/nissan_m...ange_tutorial/

I think I covered about everything but if you see anything that needs to be changed/added/modified let me know. I'm subscribed to this thread so I should get all of the replies.

I also have a timing belt change tutorial which I posted earlier.

DIY 3rd Generation Nissan Maxima VG30E Timing Belt Change

http://www.caraudiohelp.com/nissan_m...ange_tutorial/

[CapedCadaver]

i'll go ahead and be picky.

the yellow circles on some pics are only 1 pixel thick so when the pics are reduced in size as thumbs, it's really hard to see what's circled without viewing at full resolution, but if you view at full resolution then it's too big to see all of the pic on the screen.

93-94 injectors have a plug stlye change. pic (link) labelled "new"

to test ohms on injector #2 you test resistance between blackred and redwhite on the injector subharness. colors on the car-side of the harness are different, but you should be able to see the wire ends through the heatshrink wrap by pulling the harness out a little bit. I'll confirm the wire colors tonight.

[carllangford]

93 Max GXE: Do the manifold gaskets go back on dry, or do they require a sealant? I'm getting ready to replace all my injectors since two have failed.

Also, can't I skip the step of separating the throttle body chamber from the intake plenum? I'm really just interested in getting the injectors in and back on the road. I could leave that cleaning procedure for a later time and leave the plenum in place.

The tutorial is great, I appreciate it

Thanks.

[CapedCadaver]

Originally Posted by carllangford

93 Max GXE: Do the manifold gaskets go back on dry, or do they require a sealant? I'm getting ready to replace all my injectors since two have failed.

Also, can't I skip the step of separating the throttle body chamber from the intake plenum? I'm really just interested in getting the injectors in and back on the road. I could leave that cleaning procedure for a later time and leave the plenum in place.

The tutorial is great, I appreciate it

Thanks.

i've never done intake gaskets but i do know that you can pull the entire plenum/tb/duct as one piece, but i'm thinking it's slightly more frustrating when trying to reconnect the vacuum and coolant lines back onto the TB. if you can disconnect the coolant lines from wherever they hook to rather than from the TB itself, and the same with those 2 vac lines, you might be in better shape tho.

[carllangford]

Originally Posted by CapedCadaver

i've never done intake gaskets but i do know that you can pull the entire plenum/tb/duct as one piece, but i'm thinking it's slightly more frustrating when trying to reconnect the vacuum and coolant lines back onto the TB. if you can disconnect the coolant lines from wherever they hook to rather than from the TB itself, and the same with those 2 vac lines, you might be in better shape tho.

Thanks. The gaskets I was questioning were the plenum gaskets that are exposed in the injector swap. Also, now that you mention it, do you need to drain down the cooling system since TB water lines are being disconnected? Or can you just catch whatever coolant drains when you disconnect the hose?

[CapedCadaver]

Originally Posted by carllangford

Thanks. The gaskets I was questioning were the plenum gaskets that are exposed in the injector swap. Also, now that you mention it, do you need to drain down the cooling system since TB water lines are being disconnected? Or can you just catch whatever coolant drains when you disconnect the hose?

depends how much of a mess you want to risk making. if you want to be sure not to make a mess you can drain the system (might as well, if the system could use a flush or refill anyways). Often times the little hoses will just drain slowly for a long time, rather than gushing like it would if you pop off the lower radiator hose.

[nc90gxe]

Originally Posted by carllangford

93 Max GXE: Do the manifold gaskets go back on dry, or do they require a sealant? I'm getting ready to replace all my injectors since two have failed.

Also, can't I skip the step of separating the throttle body chamber from the intake plenum? I'm really just interested in getting the injectors in and back on the road. I could leave that cleaning procedure for a later time and leave the plenum in place.

The tutorial is great, I appreciate it

Thanks.

Dry. and drain the coolant some it will be a mess if you dont. you might as well seperate the tb i think the bolts are a little wierd anyway and it may come loose on its own when you disconnect the coolant lines. besides cleaning it doesnt take long. be sure to have your dual duct and throttle body gaskets before you start they were a pain for me to locate.

Forgot to pay my respects for the write-up! (A+)

[Rayovac]

Cleaning the TB isn't that bad, but getting the old dual duct gasket off was a colossal PITA. Seriously, it took me over two hours to scrape that fused crap off.

[AzureblueZ]

Hey thanks for doing this

[carllangford]

Pardon this lengthy post, however many will hopefully benefit from it.

Ok... A little history..... Several weeks ago I had a mechanic troubleshoot and replace a single fuel injector. The total bill was $500 ($320 of it was labor). He got $159 for one injector. Long story short I had two cars down at once and needed the quick repair.

So, just weeks later my luck has it that another injector went out . So I have 5 Bosch injectors on the way I bought on Amazon for $86 each. Same injector the mechanic used. In the end I'll only have about $500 in parts for a 5-injector job. I'm providing the labor this time since my other car is up and running.

So tonight I did all the removal work down to getting the (5) injectors out, using mainly the A+ tutorial and a couple other sources (AllData and FSM). Here are some things I noticed along the way and would welcome comments and/or explanations:

(1) I left the TB connected to the plenum and removed it on once piece, no problem. After seeing how dirty everything is however I'm considering separating it and doing the cleanup on it. Just not looking forward to that PITA gasket cleanup.

(2) I found the upper and lower plenum gaskets coated in motor oil. Did the mechanic do this on the install and should I repeat?

(3) I removed the fuel rail, but wish I hadn't. After I got it out I still could not easily remove the injectors and I was fearful of damaging the one (newest) that I wanted to keep. I put the rail back on and grabbed the injectors with vice grips and twisted and pulled them out. Since I pulled the rail out I plan to replace the insulators that sit below the rail.

(4) I pulled the EGR valve off the plenum, as per the tutorial, and found the gasket did not look new. Wondering how the mechanic did the job without removing this and replacing the gasket.

(5) I did manage to strip some of the screws holding the metal caps on top of the injectors. I'm buying more screws tomorrow.

(6) Do we lube the injector O-Rings with motor oil before re-install? I know they need lube, but unsure what type. The tutorial indicates motor oil but just wanted to make sure. Other sources say to lube them with gas.

(7) Based on the amount of force required to remove the old injectors, I'm a little uncertain what I will encounter trying to put the new ones in. Grabbing them with vice grips I think is out of the question. So just how do you coerce them in? Is it possible that the metal cap and it's screws can be used to drive them in, or will this result in some sort of damage? I suppose I can try and re-insert an old injector to test the method of insertion.

(8) As per the tutorial, I labeled everything that would not be obvious when I go to put her back together.


(9) One last item: if the fuel rail is installed and all injectors are in place, is that the time to test the fuel rail and injectors for leaks? Would that be as simple as turning on ignition with FP fuse installed?

Thanks for reading, and I look forward to your answers and opinions.

[BenStoked]

I havent done this, but here is what I have gathered from others:
1) you have another car, just do it
2) IDK
3) IDK
4) he is an r-tard, and reused the old gasket?
5) good luck with finding them, shouldn't be too hard, Ace, or most of the other small places are easier to find the little screws/nuts/bolts/whatever than home depot/Lowes
6)
7)engine oil, Vaseline, assembly lube, whatever, pretty much (unsure about gas. I would think no; it would evaporate before you are done. and it isn't a very good lube)
8) I would never be able to remember to bag/inventory everything. i would just figure out where it all went on re-assembly.
9) I believe so, but deferred to somebody else.

[carllangford]

Thanks BenStoked

(1) Good point
(5) Nissan stocks them @ $1.05 each.

[Pearl93VE]

Originally Posted by carllangford

(1) I left the TB connected to the plenum and removed it on once piece, no problem. After seeing how dirty everything is however I'm considering separating it and doing the cleanup on it. Just not looking forward to that PITA gasket cleanup.

Leave the actual throttle body on the Intake Manifold, but take the lower intake manifold duct off of the throttle body, you'll be happy you did when everything is said and done. Getting the gasket off is a pain in the ***, but you'll have much easier access to all of the vacuum, coolant, and fuel lines under and behind the Lower Intake Manifold, not to mention having new gaskets when you're already going to be in there is just smart practice.

(2) I found the upper and lower plenum gaskets coated in motor oil. Did the mechanic do this on the install and should I repeat?

It isn't required to coat them in oil, in fact, I would sway against that theory. Detergents in motor oil can actually deteriorate rubber over a prolonged period; if anything, I would just put a thin layer of Vaseline on the gasket with your hands and install it.

(3) I removed the fuel rail, but wish I hadn't. After I got it out I still could not easily remove the injectors and I was fearful of damaging the one (newest) that I wanted to keep. I put the rail back on and grabbed the injectors with vice grips and twisted and pulled them out. Since I pulled the rail out I plan to replace the insulators that sit below the rail.

Good idea on replacing those insulators, one of mine was busted so I just used generic one's I found at Ace Hardware (or Home Depot or whatever) and used it so it sat level.

(4) I pulled the EGR valve off the plenum, as per the tutorial, and found the gasket did not look new. Wondering how the mechanic did the job without removing this and replacing the gasket.

Scrape off gasket, and replace. In theory, you could just use some Permatex Black RTV silicone sealant and put it back on if you don't want to wait for gaskets, but having OEM stuff is always good for peace of mind.

(5) I did manage to strip some of the screws holding the metal caps on top of the injectors. I'm buying more screws tomorrow.

**** happens

(6) Do we lube the injector O-Rings with motor oil before re-install? I know they need lube, but unsure what type. The tutorial indicates motor oil but just wanted to make sure. Other sources say to lube them with gas.

Most definitely lube the **** out of those O-Rings. However, do NOT use motor oil or gas. Use Vaseline, it's thick, gooey, doesn't deteriorate rubber, and it's pretty cheap. Lube those O-rings up good and slide them over the injector.

(7) Based on the amount of force required to remove the old injectors, I'm a little uncertain what I will encounter trying to put the new ones in. Grabbing them with vice grips I think is out of the question. So just how do you coerce them in? Is it possible that the metal cap and it's screws can be used to drive them in, or will this result in some sort of damage? I suppose I can try and re-insert an old injector to test the method of insertion.

I think you'll be pleasantly surprised on how easy it is to insert the new injectors. Just put an even amount of pressure on the top of the injector and you'll eventually hear it pop in. Good to go, just screw it in once it's centered.

(8) As per the tutorial, I labeled everything that would not be obvious when I go to put her back together.

Good practice too, I like to set things up on the ground in the layout I took them out in, helps when you reinstall. kind of like an invisible blueprint.

(9) One last item: if the fuel rail is installed and all injectors are in place, is that the time to test the fuel rail and injectors for leaks? Would that be as simple as turning on ignition with FP fuse installed?

Not sure on this one as there will be other uncapped fuel lines, you can pretty much tell by looking at all of the hoses leading to the fuel rail, if they look dryrotted or are cracked where they bend, might as well replace them. If you're worried about the actual injectors leaking fuel, I wouldn't worry too much, just insure the O-Rings are lubed and they're properly fastened into place and you should be good to go.

Thanks for reading, and I look forward to your answers and opinions.

Good luck, It's not too bad.

[traxtar944]

NEVER NEVER NEVER lube a rubber o-ring or gasket with motor oil. That seal will be sure to leak and deteriorate in a couple thousand miles. Use Vaseline always. It's cheap, easy, and works every time.

Word 2 ya mother.






PS) Make DAMN sure that those injectors seat perfectly. When I did my injectors, one of the inner o-rings had a tiny rip/slice and ended up dumping fuel without stopping....totally flooded the cylinder. And that was after re-installing ALL the coolant and vacuum lines and manifolds, because there's no other way to really be sure they all seated properly without reinstalling everything. Doing a job twice because of crap like that really chaps my ***.

[nc90gxe]

Originally Posted by carllangford

(3) I removed the fuel rail, but wish I hadn't. After I got it out I still could not easily remove the injectors and I was fearful of damaging the one (newest) that I wanted to keep. I put the rail back on and grabbed the injectors with vice grips and twisted and pulled them out. Since I pulled the rail out I plan to replace the insulators that sit below the rail.

If you have time I'd say mail it to these guys http://www.deatschwerks.com/catalog/...r_services.php for their basic service that way you can have them tested before you put everything back together.

[BenStoked]

Originally Posted by nc90gxe

I took the time to mail mine to these guys http://www.deatschwerks.com/catalog/...r_services.php for their basic service. now my friend's mom (who is a psychic) is tell telling me that I will need to redo the injectors soon

fixed

[Pearl93VE]

Originally Posted by carllangford

(9) One last item: if the fuel rail is installed and all injectors are in place, is that the time to test the fuel rail and injectors for leaks? Would that be as simple as turning on ignition with FP fuse installed?

Also...

Testing injector o-rings

[nc90gxe]

Originally Posted by BenStoked

fixed

HA! It's been running strong since February, I seriously doubt there'll be any problems. But just to be on the safe side, how did they work out for you?

[BenStoked]

Originally Posted by nc90gxe

HA! It's been running strong since February, I seriously doubt there'll be any problems. But just to be on the safe side, how did they work out for you?

I havent had any problems with my original injectors (save about a month ago, but it went away, maybe time for a new one), but if i do need any, i won't bother with a reman, I will get new, and call it a day.

[nc90gxe]

Originally Posted by BenStoked

I havent had any problems with my original injectors (save about a month ago, but it went away, maybe time for a new one), but if i do need any, i won't bother with a reman, I will get new, and call it a day.

Well if you get a chance take a look at this thread deatschwerks phase 2 injectors. I did not put in the OE VG injector remans (the ones with the wire clips). I do value opinions on this forum but just like everyone else that has the opportunity, I've decided to try and pioneer something that may prove to be reliable and economical (400 for them to clean the rail, put in 6 remans, and flow test injectors).

[carllangford]

Thanks to the OP for the injector tutorial and all those who responded. I got the 5-new injectors in today and put it all back together. Runs like a champ now. Saved about $1000. Really appreciate all the help . I lubed the o-rings with vaselline as suggested and they poped right in. It was a big help putting it back together to have had the connections labled.

[kgbtaf]

Some great info in this thread. Maybe you guys can offer some advice. 2 of my injectors went bad on my '91 VG30E so i bought some a 6pk of refurbs. Installed all 6, now the car doesn't start. I get voltage to the injectors and the fuel rail gets fuel, but don't think the injectors are pulsing (used jumper wires from battery to a few injectors to see if they activated).
I checked the 2 small ground straps and the 3 or so electrical connectors involved and they all seem fine. Wondering what could be wrong here. Any ideas?
Thanks in advance for any help.

[carllangford]

Originally Posted by kgbtaf

Some great info in this thread. Maybe you guys can offer some advice. 2 of my injectors went bad on my '91 VG30E so i bought some a 6pk of refurbs. Installed all 6, now the car doesn't start. I get voltage to the injectors and the fuel rail gets fuel, but don't think the injectors are pulsing (used jumper wires from battery to a few injectors to see if they activated).
I checked the 2 small ground straps and the 3 or so electrical connectors involved and they all seem fine. Wondering what could be wrong here. Any ideas?
Thanks in advance for any help.

Did you ohm out the refurbs?

[internetautomar]

Originally Posted by kgbtaf

Some great info in this thread. Maybe you guys can offer some advice. 2 of my injectors went bad on my '91 VG30E so i bought some a 6pk of refurbs. Installed all 6, now the car doesn't start. I get voltage to the injectors and the fuel rail gets fuel, but don't think the injectors are pulsing (used jumper wires from battery to a few injectors to see if they activated).
I checked the 2 small ground straps and the 3 or so electrical connectors involved and they all seem fine. Wondering what could be wrong here. Any ideas?
Thanks in advance for any help.

Problem 1: you bought remans

[kgbtaf]

Yeah, got 12ohms on most of them (2 were a little high, but the contacts are a little dirty & oxidized & I haven't cleaned them yet). I was wondering if Flow testing might be worth it or if i should just pay full price & get some Bosch or OEM? Was trying not to spend several hundred dollars on replacements, seeing that i already spent over a $1000 on other parts. Guess i was hoping that it might be another possibility before I commit.

[carllangford]

Originally Posted by kgbtaf

Yeah, got 12ohms on most of them (2 were a little high, but the contacts are a little dirty & oxidized & I haven't cleaned them yet). I was wondering if Flow testing might be worth it or if i should just pay full price & get some Bosch or OEM? Was trying not to spend several hundred dollars on replacements, seeing that i already spent over a $1000 on other parts. Guess i was hoping that it might be another possibility before I commit.

What exactly is "a little high"? I bought Bosch 62042 injectors for $86/each through Amazon (actual supplier was The Parts Authority). I figured if I got almost 200K out of the originals I would just buy new and call it a day. I understand about saving money, but there's only so much money to save. If you've saved parts mark-up and labor by DIY, then don't cheat on the parts. Either something is wrong with some or all the injectors you bought or you hooked something back up wrong when putting it all back together.

[Greeny]

Originally Posted by kgbtaf

Some great info in this thread. Maybe you guys can offer some advice. 2 of my injectors went bad on my '91 VG30E so i bought some a 6pk of refurbs. Installed all 6, now the car doesn't start. I get voltage to the injectors and the fuel rail gets fuel, but don't think the injectors are pulsing (used jumper wires from battery to a few injectors to see if they activated).
I checked the 2 small ground straps and the 3 or so electrical connectors involved and they all seem fine. Wondering what could be wrong here. Any ideas?
Thanks in advance for any help.

Go back over your work area thoroughly, chances are you left something unhooked or something of that nature. Did you remove the distributor when you replaced your injectors?

[kgbtaf]

Yeah, made sure both ground wires were good and secure and the 3 or so electrical connectors are good. Also, sprayed fuel into the intake and the car starts up just fine. So it looks like the problem starts at the injectors. Got fuel to that point.
If these reman injectors are bad, I guess i can live with that, but it just sounded a little hard to believe cuz the seller had great feedback for over 2 yrs of selling injectors and I didn't think all 6 would be bad. My engine ran with 2 or 3 bad ones before, so i assumed that even a couple "new" bad ones would at the very least start up (but run like poopoo of course). That's why i thought i had an electrical problem cuz i don't get pulse from any of them (although to be honest I think i only checked about 4 of them). Just power to each thru their connectors.
Probably gonna go the Bosch route and cross my fingers, but just seems like a waste to have all be dead. Very strange.
I'll be rechecking the resistance soon once i clean the contacts. The fluke i was using was all over the place on a few of them.

[CarAudioHelp]

The tutorial has been updated today. A few minor changes and notes.

[jakeru]

I swapped some VG injectors recently (1989 max GXE), so can add my thoughts and methods to what has been stated already...

1. I like to remove the throttle body from the upper plenum, but leave it connected to everything else inside the engine bay. That way I can leave the coolant hoses, vacuum hoses, even the plastic intake hose that connects to the MAF/air cleaner in place. It saves time!

2. I like to leave the distributor in place. Not necessary to remove it, just unclip the cover (and unplug one of the electrical connections) is all that is necessary to access the nearby injector.

3. Not necessary to drain coolant, as someone else here mentioned. There is a coolant line connecting to the middle intake piece, but it only dribbles out a small amount of coolant and then stops. It's pretty high up, so is not going to drain out a whole lot.

4. I remove the two 12mm nuts holding the EGR valve to the middle intake piece, but I leave the EGR valve on the rest of the engine (easier that way.)

5. I find it can be really important to polish the insides of the fuel rail "bowls", where the upper injector o-ring seals, if it isn't perfectly smooth already! This caused me a lot of o-ring leaks until I figured it out. I used a fine "cross-buff" with a die grinder until they were really smooth. And of course, don't attempt to re-use 20 year old o-rings either, if you want them to reliably seal!

6. I have no problem using oil to lubricate the o-rings. Gasoline is a much stronger solvent than oil, so I think it does no harm. Obviously, the rubber o-rings are at least somewhat solvent resistant if they last for 20 years being continuously exposed to gasoline. The oil lubricant helps them install in a more relaxed, kink-free position, which is a good thing I think.

7. Watch the torque specs on the intake pieces. Especially the upper intake piece! (which only takes a paltry 5.5 ft-lbs on those big 6mm allen socket head screws!)

8. Check the inside of your injector electrical connectors for green corrosion! I found all of mine had significant green corrosion, especially the back three (with straight rubber boots, which were all hardened and torn), and should all be replaced. Also the back three had green corrosion pretty bad under the boots, where the connectors crimp to the wires. (It occurs to me that a bad, intermittent injector electrical connection could be a cause of injector failure!)

If you are looking for replacement injector connectors, be aware that the common Bosch "EV1" injector connector doesn't appear to have the correct, "offset" middle pin that our 3rd gen maxima's OEM JECS injectors have, so they won't work.

I did source some connectors matching our JECS injectors, which can be cut off and soldered onto our maxima harness from this $21 (plus shipping) harness of three connectors, from courtesy parts here:
http://www.courtesyparts.com/300zx-i...-p-624193.html

This 1990-1992 300ZX harness also has the "new and improved" connector, which eliminates the leak-prone rubber sealing boots in favor of weatherpack type seals (one individual seal per wire built right into the back of the connector.)