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 injectors
2. Set of 94-96 Fuel Rails
3. 94-96 injector harness
4. 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

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).

90 Q45 Base 246,000 miles

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

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

Have you done a power balance test yet?

Discover the power of the button!

You are correct!

Heath

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

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?

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

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.