Injectors

[Terranical]

I've recently had all four injectors changed in an attempt to reduce the amount of black smoke (which they didn't, it's now worse!)

The guy that fitted the injectors showed me four small (about 15mm diameter) copper washers which were below the nozzles, in addition to the four conventional sealing washers - he said he had never seen that before, and didn't believe they should be there, so he left them out.

Has anyone come across this before, and have any idea why they should there?

[11redrex]

When I took the injectors out of my old mav there were copper washers under the injectors, and most of the injectors I've seen for sale come with new ones. There are several "gaskets " shown on the parts diagram, one is described as 15mm id and 18m od, one is 11.5mm id, on is 11mm od.
Black smoke is too much fuel, or not enough air. Have you checked everything else ?
If they were there and have been for some time, I would guess they are meant to be there.

[stinka]

I know common rails have copper washers.

Bloke sound like an idiot, " I don't think they should be there " isn't really the thing you'd expect to hear from someone that was following manufacturers specification and had bothered checking with Nissan ...

[Terranical]

The company that refurbed the injectors for me gave me a set of new washers, four copper 18mm od and about 12mm id, and four aluminium "bleed-off washers. They said that was a complete set. They did not include the four small copper washers (about 11mm od and 8mm id) that were found below the old nozzles.

My mechanic fitted the four large copper washers between the injectors and the block, and the bleed-off washers in the same place as the old injectors had them.

The small copper washers were quite badly squashed and distorted, so couldn't really have been re-used below the nozzles - if they were necessary one would think that the refurbishers would have provided four of them as well as the others.

[Terranical]

The company that refurbed the injectors for me gave me a set of new washers, four copper 18mm od and about 12mm id, and four aluminium "bleed-off washers. They said that was a complete set. They did not include the four small copper washers (about 11mm od and 8mm id) that were found below the old nozzles.

My mechanic fitted the four large copper washers between the injectors and the block, and the bleed-off washers in the same place as the old injectors had them.

The small copper washers were quite badly squashed and distorted, so couldn't really have been re-used below the nozzles - if they were necessary one would think that the refurbishers would have provided four of them as well as the others.
Further to the above, I've just had a look at the parts manual, and it doesn't appear to show a washer below the nozzle - odd!

[elpeede]

The copper washers are to provide a gas tight seal and should be replaced when injectors are removed unless you anneal the washers (heat) to ensure that they are sound when refitted. Regardless of if they were previously I would have fitted them. Making sure that as much as possible the orrifaces are as clinically clean as I could get them to ensure no debris allows air through the seal.

Has the air filter been replaced recently, not enough air could be as simple as a heavily clogged filter.

I don't know enough about nissans to comment further, this is based on my experience with other motors.

[Terranical]

The copper washers are to provide a gas tight seal and should be replaced when injectors are removed unless you anneal the washers (heat) to ensure that they are sound when refitted. Regardless of if they were previously I would have fitted them. Making sure that as much as possible the orrifaces are as clinically clean as I could get them to ensure no debris allows air through the seal.

Has the air filter been replaced recently, not enough air could be as simple as a heavily clogged filter.

I don't know enough about nissans to comment further, this is based on my experience with other motors.
The air filter was pretty dusty until a few weeks ago. when I tapped it until no more dust came out, but I'm thinking of taking it out completely and giving the car a short run to see if that makes any difference.

The main sealing washers were replaced with new, my quandary is over the 4 small washers under the nozzles, which aren't shown in the parts manual. That's what makes me think they shouldn't be there i.e. when the injector is tightened down two copper washers have to be compressed, with the possibility of one bottoming out, preventing the other from sealing properly.

[geoffdown]

The air filter was pretty dusty until a few weeks ago. when I tapped it until no more dust came out, but I'm thinking of taking it out completely and giving the car a short run to see if that makes any difference.

The main sealing washers were replaced with new, my quandary is over the 4 small washers under the nozzles, which aren't shown in the parts manual. That's what makes me think they shouldn't be there i.e. when the injector is tightened down two copper washers have to be compressed, with the possibility of one bottoming out, preventing the other from sealing properly.

The small washes u talk about should be there they are called heat shield washes they start off with a lip round which gets squashed mine had both small heat shield washes as well as the bigger seating washer sound like this bloke does nt know what he's doing goodly.