94-96 style injectors on 90-93 Q... INFORMATION/PICS

[elwesso]

Theres been a lot of deliberation on what will/wont work as far as injectors on 90-93 Q45s.

before proceeding, review your notes on the plenum job because Im assuming you know whats going on when you take the plenum off.

With ethanol throughout the country its imperative we find something that handles ethanol better. The obvious choice is the 94 style injectors. Im not convinced this is the BEST solution, but it is definitely the easiest/best solution we have right now (outside of retrofitting something else)...

Ill be posting another picture thread but long story short I did some work on user Johnny Rocket's Q with 38k miles. It had 2 GOOD injectors in it...

So in order to do this, you need the following:

1. Set of 8 94-96 injectors2. Set of 94-96 Fuel Rails3. 94-96 injector harness4. 94-96 fuel rail-to-runner seals (donuts)*

You may be thinking "deatschwerks sells an adapter kit for this". These are collar adapters that will be obvious what they do later in the thread to allow the 94-96 injectors to fit in the 90-93 fuel rails.. However the BETTER route is to go with 94-96 fuel rails, which brand new from nissan is cheaper than the kit from deatschwerks by about $50.

Joe is getting a few sets of new OEM rails in the country now (backordered from Japan)... Deatschwerks sells 94-96 injectors for about $65 each with a 1 year warranty... Not a bad alternative, and for the record deatschwerks claims they see around 1% of returns in their warranty period, not bad at all!!!

Anyway, long story short this is a BOLT ON AFFAIR.. The only thing modification you have to do is eliminate the washers and only use the plastic spacers. This could probably be eliminated if you bought #4 on the list, we did not.. Anyway, without further ado, here are the pics!

90-93 rails on left, 94-96 on right (90-93 injectors still in rails)



94-96 rails on right, 90-93 on left.. Note how much bigger the holes on the bottom of the rails are, this is the primary difference between the pintle type injectors and the rotary disc injectors.



94-96 injector in rail

+

Spacer modification- note how the top black plastic spacer on top is sandwiched between 2 gold washers, and the bottom one isnt. This is because the seals dont sit right, so you need to let the 94 fuel rails sit a little farther into the seals.. Thats why I put a star around item four (4) because i think you'd be better off using the 94 seals and theyre cheap.



94-96 injectors bolted on car



90-93 rails/injectors

[goody90q45]

Good job Wes. Johnny Rocket is a lucky man. What do you think the miss is from? No scan program on your laptop?

I'll be doing the same this spring. I have a DetschWerks cleaned rail ready for the 94Q and will have the used rail with injectors readied for the 90Q at the first sign of injector problems (fingers crossed).

[jimbyjimb]

Thanks for getting your elbows grimy for the benefit of all yet again.

[Q45tech]

Be sure to change to new O2 to give ecu best chance of learning any differences in injectors.................power balance and resulting variations should be interesting.

[Q451990]

4. 94-96 fuel rail-to-runner seals (donuts)*

Thats why I put a star around item four (4) because i think you'd be better off using the 94 seals and theyre cheap.

Wes,

The 94-96 style rail-to-runner seals are thicker and smaller in outside diameter vs. the 90-93 seals, so there is no good way to use them. I tried. The only way to make them work is to open up the existing 90-93 style seals and then glue the new seals in place with RTV or something. I found it just a little too convenient that the existing 90-93 seals fit perfectly around the raised area on the 94-96 rails by lowering the rail down just a bit - which you did by eliminating the washers. I'm not even entirely sure that lowering the rails is necessary, but I chose to do it just to be safe.

I chose to use a stack of two (or was it three?) washers and eliminate the spacer, since I had concerns about the spacers cracking if I torqued the rails down without the washers there as a buffer.

Heath

[Denver90Q]

Wes,The 94-96 style rail-to-runner seals are thicker and smaller in outside diameter vs. the 90-93 seals, so there is no good way to use them. I tried. The only way to make them work is to open up the existing 90-93 style seals and then glue the new seals in place with RTV or something. Heath

Thats what I did on my 1990 as I was afraid of possible vacuum leak otherwise.

Have you done a power balance test yet?

[maxnix]

I chose to use a stack of two (or was it three?) washers and eliminate the spacer, since I had concerns about the spacers cracking if I torqued the rails down without the washers there as a buffer.

Heath

I think TexasOil was the first to note this solution in IOM.

[Johnny Rocket]

Hey Wes did we do a power balance test yet? Or was that 8000 RPM shift a power balance test?

[BLACKonBLACK98]

wish i would have had this info when i put my car in the shop. oh well... mental note for next time.

[Q451990]

I think TexasOil was the first to note this solution in IOM.

You are correct!

Heath

[elwesso]

No power balance yet, didnt have my consult and also dont have a laptop...

Thanks for the info heath, that makes me feel a lot more comfortable in my decision.

[Johnny Rocket]

Wes your email is down for some reason...I have lots of laptops...call me when you get a chance

[Q45tech]

In last week we have seen 3 more 94 95 with failed injectors.

[Drake57]

Wes,

The 94-96 style rail-to-runner seals are thicker and smaller in outside diameter vs. the 90-93 seals, so there is no good way to use them...Heath

So which style seal should be used?

PS - which seal is it in which a failure can cause hydro lock? Are there two seals on each injector, as well as the rail to runner seal?

[elwesso]

theres 2 O rings that go around the injectors that seal it in the fuel rail, and theres a rubber donut that seals the fuel rail/injector assembly to the lower manifold.

[Jesda]

This thread is awesome. Thank you for taking the time to explain and photograph everything.

[masoQist]

When I first read this thread and saw the differences between the older and newer style rails, I was skeptical about this setup. However, after examining and test fitting the parts, it all makes sense now. Both the new and old style rails seal against their respective manifolds by means of a flange-type seal, or a gasket being compressed between two flat, parallel surfaces. In both cases, the sealing surface on the rail is a narrow ring (about 1.5 to 2mm wide) while the sealing surface on the manifold is a wide ring (about 7.5mm). However, on the newer rails, the ID and OD of the sealing surface are much smaller – so much smaller that when using the newer rails on the older seals, the original rail sealing surface misses the rubber seal entirely. The interesting part in all of this is that the newer rail has a machined 45-degree conical surface outside of the original sealing surface. You can see this clearly in the last photo above. When the newer rail is installed on the old style manifold and rubber seal setup, the inner edge of the rubber seal seats right on this machined conical surface, which creates a compression-type joint.
Modified by masoQist at 10:04 PM 12/14/2009

[mxr662]

So which are the fuel rail to intake runner seals?

[mxr662]

part number anyone

[Infinitiguy19]

1990-1993 Q45 Injector Insulator--16636-60U00-

[mxr662]

actually i need the 94+ part number to match my 1994 injectors to my 1990 runners.

[Infinitiguy19]

Prod.M/Y:0293-0795----16636-41B00-

Prod.M/Y:0795- ----------16636-72P00-

[elwesso]

actually i need the 94+ part number to match my 1994 injectors to my 1990 runners.

just use the 90-93 insulators... in other words, dont change them out, or get the ones that originally came on your car..

The 94-96 Q45 lower intake runners have a smaller OD where the insulator sits in the lower intake manifolds.

[BCC93QT]

I am running 94-96 injectors in my original 90-93 fuel rail. The only difference i think is the spacers that raise the injector a centimeter or so. Also the rubber piece on the top of the injector is different. Deatschwerks has a nice kit that covers this. All has been well for about a year now injector wise

[mxr662]

4. 94-96 fuel rail-to-runner seals (donuts)*

This could probably be eliminated if you bought #4 on the list, we did not..

That's why I put a star around item four (4) because i think you'd be better off using the 94 seals and they're cheap.

So don't get number 4

[freddyboy]

its been about a year since I have researched the injector prob with the Q I see it is still ongoing. I am ready to tackle the job and now I see the best way is to go to the 94-96 rail and Injectors. Do we have a central location for the posts and pics/vids of how to do this? thanks to elwes for the great pics. fred

[elwesso]

welcome to NICO Fred... This is really where I put all the info.. Feel free to ask questions or post another thread specific to what you're doing...

[Drake57]

Is the 94-96 injector and rail set up any less prone to seal failure leading to catastrophic hydro lock and engine destruction than the 90-93 style?

Can anyone say the capacity rating (lb/hr or cc/min) of OEM Q45 injectors?

Thanks, Drake.

[elwesso]

Is the 94-96 injector and rail set up any less prone to seal failure leading to catastrophic hydro lock and engine destruction than the 90-93 style?

Can anyone say the capacity rating (lb/hr or cc/min) of OEM Q45 injectors?

Thanks, Drake.

That has nothing to do with the actual injectors... It has to do with installing them improperly and causing the O rings to pinch, causing fuel to dump into the cylinder... Equally possible on the 90-93 or 94-96..

The stock Q injectors are 370cc.

[OwnerCS]

Has anyone replaced their O2 sensors as part of this operation? I didn't see any further references. Do you use O2 sensors from a 90-93 or 94-96?