So I was thinking about why an injector would fail...It can't be many things. I mean, it is just a "plunger" with a coil wrapped around it, which moves the plunger via a magnetic field when an electric current is run through it.

So, my thought is, maybe it is gummed up...I am going to take it out and clean it...It works about half of the time meaning it is not completely busted. I'll let you guys know if it makes a difference or if I end up ordering a new one.

But as the title indicates, has anyone done this? And what was the outcome?

 

IMHO,i dont think injectors mainly fail do to gumming up,i believe it to be a mechanical failure..Moving parts just eventually wear out..

 

But mechanical failure would indicate it not operating at all...my car still runs fine at least half of the time.

 

Moving electrical parts can and do intermittently fail,for instance,i have had to put 3 fuel pumps in my car since i have owned it,all of them failed intermittently for a while until finally completely failing...My injector also failed in the same manner,in and out for a while then eventually,nothing...

 

I've been thinking that the needle probably just gets worn or something. It would be useful to know where exactly the resistance comes form inside the injector.

I dont know what is in the fuel that could gunk it up though, some random dirt maybe? Gasoline is already a solvent, and the fuel filter is supposed to pick up the rest so there shouldnt be much in there that can stick and get built up over time. Maybe if NEW injectors are failing too soon, it might be a good idea to replace rubber fuel lines in case they are coming apart on the inside.

I also heard that you can get dirtier gas if the gas station just got refilled and all the settled dirt is agitated, but I'm not sure if thats just a myth. I assume some of it could settle in the gas tank of the car over time, but I've never seen the inside of one after thousands of miles.

What about placing two fuel filters in line with each other, any cleaner then?

 

these injectors typically fail electrically.
I'm THEORIZING (no proof available) that when they do the intermittent functioning thing. they are windings that have broken and they will intermittently touch and solder themselves back together until the next time.
I've seen bulbs do it before.

 

I've seen our power door locks do it before.

 

I regularly run techron injector cleaner and mine still fail every once in a while. Our injectors just suck. I thought you told me you use cleaner too?

When I get a chance I'm going to see if I can fit a set of top feed injectors under the stock plenum.

~Alex

 

ugh I dont trust those cleaners, they could dislodge some crap and bring it to the injector

 

Thats why I change my fuel filter every year. You cant just service one part of a system gotta clean it all.

~Alex

 

I have a set of Branson Ultrasonic cleaners here at work. I used them to clean a set of 370s and a set of old VE injectors that were gummed shut.(They wouldnt even fire, they had sat with fuel in the rail for like 5yrs) I couldnt believe how cloudy the cleaning solution got from all the crap coming out of the filters!! After they were done cleaning for like an hour, they all fired and sounded strong.

Ive been using them for like 6 months and the motor runs super smooth!!

BTW, this is the same process that RC and other injector shops use to clean injectors.

Im just lucky...

 

[QUOTE=mikekantor had a good point
Maybe if NEW injectors are failing too soon, it might be a good idea to replace rubber fuel lines in case they are coming apart on the inside.
qUOTE] BLEED THE GAS LINE....
you could pull the fuel feed line at the injector rail or under the fuel filter and route it and or extend it to a clean empty gas can and turn the key to the ON position but dont start it and let some gas pump into the container(it pumps fast so dont let the container fall over) and look for particles if you think your fuel lines are breaking down you would definitly get a lot of good gas flow and would see anything in there as far as chunks of rubber . (BE VERY CAREFUL WITH GAS) i bleed a little out like this when changing gas filters so i would know if particles are staying in the hose that wont stick in the filter (since ive noticed
the old filters will drop particles out of the bottom side that the gas flows through) since ours go from bottom to up . this is also good for DRAINING wrecked or parts cars as long as theres not damage to the system from the accident

 

So uh how much would you charge to clean mine? I just want to know if they are actually flowing. And make 100% sure they are clean.

~Alex

 

I was going to just send them to Withchunter they only charge $17.- per injector. But when I pulled mine to send them they went on vacation or something!! So I just tried them in my cleaner @ work.

I would be willing to do it, but for the price, you can get a flow sheet and a pro to do it..

 

These injectors aren't worth $102+shipping. There are cheaper places but I don't want to spend more then $30-40....

What cleaner did you use? I'm thinking of making a cleaning stand or something.

~Alex

 

I used a Bransonic 1510 heated ultrasonic cleaner and the Branson Industrial cleaning solution. I let them clean for about 20 min then used a 9v battery to cycle them open and closed every few minutes for the next 40min or so. Then I made a stand to backflush them @ about 30psi with light penetrating oil. Then continued to cycle on that stand every 2-3 seconds for a couple of minutes.

Ultrasonic cleaning while cycling is probably the only way to really get them clean.

 

with the difficulty of removing the fuel injector, I wouldn't mess with cleaning them. Put in new ones. All of mine that failed were electrical failures and yes, they were intermittent.

You didn't say if you checked the resistance (ohms) of the injector coils. They should be about 11 or 12 ohms. I bet you will get ohm reading of 25, 75 and higher.

whatever you do - do not buy rebuilt injectors.

 

The use of some type of cleanter will only cause failure due to all dirt/deposits becomming loose.

 

that is totally inaccurate.
the cleaner hurts because it removes the coating off the windings of the injectors coil which causes them corrode and fail

 

So how difficult is it to replace your injectors ? I know you have to remove the intake manifold, but is seating/removing them tricky (i.e. Am I going to have to take apart the engine to reseat them ?)

 

Afraid you are the one that is wrong/inaccurate there..............

The coil on the injector is housed in a "plastic" molding that prevents the windings of the coil ever even coming into contact with fuel - the needle valve's mechanical operation is tightly governed by that molding to endure the magnetic properties of the assembly stays constant and the movement of the valve is consistent and predictable.

If an injector fails because of additives in the fuel and coil resistance showing a measured increase, it sure is not because of the injector's coils getting chewed/corroded - its plain bad luck.

I sure can however see a dislodged piece of dirt (because of the actions of the "cleaner" added to the fuel) fouling and changing the needle valve's mechanical movement characteristics.

.............. and for the record:

Measuring the injector's coils resistance says one thing and one thing only - ie - the coil resistance is either in-spec or its not.

It says absolutely nothing about the injectors ability to open and close on demand. You will be able to measure a 100% "as expected" coil resistance on a particular injector and it will mechanically be fouled/blocked/etc and totally unable to function or serve its purpose.

 

Have to agree there.
But the 2 injectors I have had fail, have been electrical faults and have been picked up by measuring the resistance of the injector, each time they were out of spec, usually measured around 50 ohms. Although a simple resistance test can't claim the injector is good, it can identify it as the bad one if it has a similar fault and is probably the easiest and quickest test.

 

My bad:

That "enDure" you quoted should have been an "enSure"

 

so you've taken apart the nissan injectors?
the fuel flows past the coil on our side feed injectors, I've spent too much time talking to rebuilders about them. So I know where the failure is.
Nissan Released a TSB specifically addressing the issue.

 

FSM (the ultimate authority... is it not?) says specifically to test resistance as an indicator of failure, and nothing about flow testing. I dont think anyone here has replaced a failed injector that still gave 10-14ohms.

 

Once you have the intake plentum chamber removed (you don't remove the intake manifold itself), the injector will pull out with a pair of channel-locks, although guys up north seem to have a more difficult time, probably from corrosion. If you haven't done it before, you will probably need half a day to do it. And don't forget to check all the fuel and vacuum hoses hidden by the plentum chamber and replace if necessary.

As for the firestorm I started by suggesting checking injector coil resistance, all I was trying to say is check it. You can't automatically say an injector is plugged, jusy like you can't automatically say the coil is bad. You have to check it.

However, if the injector has 100k miles on it - replace it. And if you are going to tear the car apart to replace one, replace all 6 because when one goes, the others will follow behind it.

 

So do I need to remove the fuel rails or can I just pull them out with the fuel rails still in place ?

 

I've done both, but I think its easier to leave them in. If you remove them, then the only convenient way to work is to lock it in a vise... but thats no different then having them sit securely in your engine. The only time I would pull the rail is if you're changing a front injector but leaving the plenum on.

Someone once posted some great advice here so I will repeat it: once you remove the cover that holds down the injector, reinsert one of the screws, rotate the injector so the harness is above that screw, and use the screw's head as a pivot for your screw driver when you pry it out. The injector will rise slightly, dont force it too much past that or you will destroy the plastic, instead have another flat-head ready and insert it in the opening. The key to getting them out is lifting symmetrically from opposite sides.

 

Just got done replacing bad injector and the car runs like new again...Also gave me a chance to replace some old and brittle fuel and vacuum lines...Not too bad a job, but still kind of a b!tch...I just hope I don't have another injector **** out on me anytime soon. The intake plenum had never been touched before, either. I busted off a lot of factory zip ties and such.

It's also good to see that my engine is really clean on the inside...not bad considering I rolled over 150k last week and I will be taking it on yet another 1000 mile road trip this weekend. I will not be able to test and tinker with the bad injector, as it got man-handled a bit being removed from the fuel rail...But I will dismantle it and see if anything looks odd (not that there's much to see.) I took some pics with my new digi and will post them later on...Right now I'm tired and going to bed...That is all for now!

 

wonder where you got the injector from

 

Must've fallen off a truck...

 

at that price , you'd think so

 

Whachu talkin 'bout, Brian? Those little suckers are pricey!

 

beats $140 ea w/o o'rings at the dealer

 

yeah on the o'rings, I had a set already but was pleasantly surprised to see them in the package. expect another injector order from me soon!

 

yeah, the fact that they don't normally include o'rings makes no sense to me. So I include them