therieldeal

iTrader: (2)

so i put some thin metal washers between the rail and the head, and used the plastic spacers above the rail to keep everything centered. everything seems to fit fine, but i have to finish wiring up the MS again so i can apply fuel pressure and check for leaks.

flipt86

iTrader: (4)

i ended up taking one end of the plastic isolators and putting them on the belt sander and sanding them to about half thickness... has worked so far, but i'm not really happy about it. I told travis about the problem after they sent me the new spacers...

therieldeal

iTrader: (2)

mine seem fine at this point, i idled the car up to full temp and drove it slowly up and down the street once. running fine and no leaks. i'm waiting for axle nuts from toyota so i couldnt really beat on it or drive fast lol

TurboRoach

iTrader: (3)

The set I have in my 1.6 are short like that as well. I left out the spacers and they haven't leaked yet (4 months). I couldn't get a response from DW so I used them.

I've been able to get them to idle at ~16.5.

therieldeal

iTrader: (2)

its been running about 200 miles now, no leaks at the injectors. idle is no problem, very pleased!

in other news, some NPT fittings on my fuel rail that had been installed and untouched for 2 years randomly started leaking yesterday. all set now though.

Deatschwerks

I need to know how many of you have had a problem, please see this thread in my vendor forum
I will get this resolved asap
https://www.miataturbo.net/forum/t39928/#post464498

OZMX-5

Uhmmm.... sorry if I completely missed it, but why has no one mentioned that you received NB injectors instead of NA ones.

therieldeal

iTrader: (2)

all i know is that i ordered 94-97 injectors which should fit, and they were too short. i know nothing of the NB motor or its injectors, as i do not have one :P

OZMX-5

You got sent the wrong ones mate.
NA injectors and NB injectors look profoundly different, as made stunningly obvious in the original post.

Send them back, get the vendor to send you the correct ones, simple.

I have no idea why you all have gone through all the trouble of putting in spacers, removing the plastic heat-sinks (which is an important part by the way) when it's obvious the two injectors are completely different by design.

And as for the need for 600cc injectors.....

therieldeal

iTrader: (2)

So running my rx7 550's at ~80% duty cycle and wishing to run a couple more pounds of boost doesn’t indicate a need for 600's?

I'll replace the steel washers with some sort of heat resistant composite ones, thanks for the tip on heat insulation I didn’t even think of that.

TurboRoach

iTrader: (3)

You can use a NB injectors in an NA. They work just fine, and are both the same length.

OZMX-5

Correct, and I stand corrected

Here is a photo that I took earlier today to prove it:



So you guys definitely got the wrong part.

As someone else suggested earlier, they may be WRX injectors, but then again, I also heard WRX injectors are direct fit.

therieldeal, I wasn't referring to you when I made the 600cc comment. You forget that the original poster is flipt86 which, and Im just going by his sig, has a mildly modded engine.

flipt86

iTrader: (4)

And I bought 600's because I don't like buying parts more than once if I can help it... I just bought a stock longblock today... My internals are coming over the winter. Do it once, with plenty of headroom. We all know how power hungry we get.

Norm

I haven’t seen a definitive answer here about injector length problems, so I assumed that everyone solved their length issues. Now I have a similar concern with the Deatschwerks 600cc injectors that I received for my 2002 1.8 so I need to revive the discussion.

When I received the 600’s they were about 1/8” shorter than the stockers, measured from the bottom of the lower isolator (at the head end of the injector) to the upper end of the injector tip, just above the o-ring. See photo. Did not get a comparison photo with stock injector. The upper isolator, however, was twice as long (thick) as the stocker. When I installed the 600’s the fit was very tight because the longer isolators contacted the fuel rail socket earlier and had to compress much more to allow the fuel rail to bolt down completely. The car started and ran, but I later had a great deal of trouble tuning the idle with my Adaptronic, even with Travis’ help. Idle was very erratic - one minute it idled well, the next minute it was all over the place. I looked for vacuum leaks with no success, but didn’t inspect the fuel rail. Finally, I pulled the plug on the ECU/600cc injector install and reverted back to stock ecu and injectors for a driving trip I had to make in the Miata. Upon removal of the 600’s I found two of the upper isolators were crushed and split.

I think I understand that the upper isolator simply acts as a dust boot. The fuel seal is provided by the o-ring at top and the lower isolator/doughnut at the bottom which is compressed into the socket in the head by the pressure exerted by the fuel rail socket in contact with the hard upper end of the injector. The fuel seal at the bottom may not be critical, but it seems to me that the lower seal is necessary to prevent vacuum leaks and/or pressure leaks while on boost since the lower end of the injector should feel the same pressures that the manifold experiences. Does this sound correct?

If this is correct, then a 1/8” shorter injector would result in much less pressure being exerted on the lower isolator/doughnut. Deatschwerks says that the lower isolator can absorb 1/8” more compression, but my point that 1/8” less compression might not result in any compression. Maybe it could be the source of my vacuum leak? Of course I will inspect and test it thoroughly when I reinstall the 600’s, but I am not ready to reinstall them yet. I am not convinced that Deatschwerks sent me the correct injectors. They seemed very vague about it on the phone. They never really confirmed that I had the correct ones. They felt that the difference in length was not significant.

What do you think? Has the length question been definitively answered and I just missed it? Also, could someone provide measurements of a stock injector (2002 model if that matters) from the bottom of the lower isolator/doughnut to the top of the injector? In my rush to leave town I installed the stockers without recording that measurement and I am now relying on memory for the length.

Sorry this post is so long.

ftjandra

iTrader: (6)

I measured 70mm. My injector is from a '94 Protege (1.8BP).

--Ferdi

Norm

Thanks, Ferdi. My 600's measured 66.5mm (2.75") compared to your 70mm (2.75") which indicates that my 600's are, in fact, 1/8"shorter. My memory was about right after all. Thanks for the help.

BTW, your sig says 343 whp on your Protege. That must be a wild beast.

OZMX-5

I don't know how else I can say this:
flipt86, therieldeal, et al received the WRONG injectors, and unfortunately, so did you Norm.
Did you see the photo I took of NA and NB injectors?

The others have played around with different size washers, spacers, filing down spacers, not using spacers, etc etc, to FORCE them to fit, and that is just ridiculous.

My experience with goods I bought from US retailers has been exceptional. If something is wrong with a product I purchased (which has been only a couple of times out of the dozens of things I bought from the US), they go out of their way to rectify the problem or replace the parts, and they have been very curteous.

This issue of injector length is really baffling me.
Wrong product = replacement or refund. Why is it not that simple in this instance?

Staff from the company in question are active members of this forum and their silence speaks volumes to me.

I make no apologies for having a "rant", but this is a very serious issue in my opinion for the simple fact that if you have misfitting injectors, you run a very high risk of fire.
I'm only looking out for fellow enthusiasts' safety here.

end of rant

OZMX-5

Sorry, I'm going to have to continue my rant as I just took a look at flipt86's photos and what he/she wrote.

Norm, they gave you wider top "spacers" (whatever they are called) in order so the fuel injector sits further out of the fuel rail and thus effectively increasing it's length. Obviously they know the length is incorrect.

Although the O-ring is the main seal against leakage, the top of the injector MUST sit flush in the fuel rail. The reason why the top spacer broke is, as you mentioned, because it's too wide and when you tried to tighten everything back up, you are forcing the injector into the fuel rail hole (because the top edge is not yet sitting flush) and thus squashing the wider washer until it cracks.


Allow me to quote:

Ockham's Razor : is the principle proposed by William of Ockham in the fourteenth century: ``Pluralitas non est ponenda sine neccesitate'', which translates as ``entities should not be multiplied unnecessarily''.

In other words, the simplest explanation is usually the correct one.

Please do not try to put these back in. Please take them back.

[Edit]

Here is a photo I just took of spare NA8 injectors, Nippon Denso part# 195500-2180:



As you can see, I can confirm ftjandra's 70mm length from top edge of injector to bottom edge of isolator spacer dougnut.

I can see a "Denso" name on your injectors, is there no part number?

therieldeal

iTrader: (2)

Ok I think I figured out what happened.

Norm has a 02, but he received injectors for a ~96. I have a ~96 equivalent, but I received injectors for a ~02. In both cases the injectors themselves are actually identical, just the top spacers are different. The top spacers that I received were much thinner, they looked like the stock top spacers.

The problem I have is this: even if I had gotten the right spacers (the ones Norm had), they would "correct" the fitment, but greatly reduce the distance that the o-ring groove extends into the fuel rail. On my custom fuel rail, the injector bores are slightly counter-sunk, and I fear that the o-rings may not seal correctly. That would be a real hazard.

I think I am going to stick with the setup I have now... it seems to be working just fine. I may replace the new thin washers/spacers with some sort of composite insulating washer, but other than that I will leave it alone.

Aside from this fitment issue the injectors are working great... it idles better than it ever did with the RX7 550's, but that may have been due to the relatively unknown opening time of a 20 year old OEM injector.

Norm

I think you are correct, OZMX-5, about the injectors being "wrong" or at least not "right". I also agree that Deatschwerks' silence here speaks volumes. I am at a disadvantage because I know nothing about injectors and I am dealing with a company that is supposed to be the "experts". That is why I have asked for some other forum member comments to make sure I understand how the injectors are supposed to fit before making an argument to the supplier.

Something that Mike at Deatschwerks said on the phone may explain why some of our members injectors have worked better than others. He explained that they have to group injectors into specification ranges that allow some variation so that a larger number of units can fit several different applications. In other words, not every injector is specific to that application, it may also fit other applications while not replacing stock injector fitment perfectly on any of them. This concept might work fine for injectors with o-rings at both ends, as some axial play may not cause a problem, expecially if the play is filled with a pliant rubber grommet. But for injectors requiring some axial compression to seal at the bottom, this may not be a good idea. My theory is that some of us may have received correct length injectors and some may have received varying lengths, apparently shorter than stock by different amounts - 1/8" to 3/8" by my observation. We may all be getting rebuilt injectors from the box of "one size sorta fits all".

By the way, I think the Deatschwerks injectors are certainly rebuilt, not new injectors built for our cars. I inspected mine with a magnifying glass to identify the part number. I saw some generic moulded-in numbers and one recessed area where a series of numbers (probably the original part numbers) had been obliterated, apparently by a hot object. This was exactly the same on all four injectors. I reported all these observations to Deatschwerks in an email and they ignored the information.

Some injectors may seal better at the bottom end simply by luck. Upon close inspection, I found that the lower isolator/doughnut is slightly tapered such that the diameter at the top of the isolator is slightly larger than the bottom diameter. On some of my injectors the isolator would stick in the head socket and some would come out with the injector while trial fitting. The fit on the injector is reasonably tight, so maybe a seal is achieved in some cases and not in others even without proper axial compression from the fuel rail.

I think many buyers "adjust" their injectors to fit simply because schedule sometimes is tight and the return process could take a week or more. In my case, I have no reason to believe I would receive better fitting injectors if I did return them. I will have to consider rigging mine too if I can become confident of the adjustment.

The only way to "increase" the effective length of the injector is to use longer lower isolators or space them out by the length shortage. For injectors 3/8" too short I would not like the idea, but for 1/8" shortage how about a 1/8" thick steel spacer located inboard of the lower isolator? The compressed isolator would seal against the bottom and wall of the injector socket in the head and would seal around the barrel of the lower end of the injector. Any feedback from you guys would be appreciated.

I wish I had spent just a little more for RC550's.

Norm