Good Fuel Injectors for 1991 Q45

[vin27]

Hello all,

I'm looking at replacing all the fuel injectors while I got
the top off, any recommendations on if it's best to
go with OEM, or is aftermarket reman pretty good?

Here is where I found the OEM
http://www.infinitipartsusa.com/partloc ... atalogid=0

And then for the cheapones, I found these:
http://www.thepartsbin.com/guides/infin ... ector.html

All the best,
Vin

[OwnerCS]

Hey Vin - Welcome to NICO.

For the 91 model, you want to upgade to the Phase II injector used in the 94-96 model. A significant design improvement was made on the Phase II injector.

With that said, you also need to upgrade the injector rails to a Phase II rail and wiring plug.

When I replaced my originals last summer I went with BWD (black dots) for a 94 model which are about $130 now days.. Sometimes you can get a parts store like OReiley to "cut you a deal" at $110.

One of our NICO sponsors, DeatschWerks in OKC, sells an adapter kit so a 94 injector can be run in 91 model. I run the DW adapter kit. Also, I understand DW has some "good pricing options" for Phase II injectors. Many members have had success with DeatchWerks.

I would give Chris at DeatschWerks a call to see what kind of pricing options he has to get your injectors upgraded to Phase II. Also, ask about ethanol compatibility.

http://www.deatschwerks.com/q45

Be sure to pressure test the injectors in the rail for any o-ring seepage before you start bolting down the rails as in the picture below.

[maxnix]

For the 91 model, you want to upgrade to the Phase II injector used in the 94-96 model. A significant design improvement was made on the Phase II injector.

With that said, you also need to upgrade the injector rails to a Phase II rail and wiring plug.

When I replaced my originals last summer I went with BWD (black dots) for a 94 model which are about $130 now days.. Sometimes you can get a parts store like O'Reilley to "cut you a deal" at $110.

Be sure to pressure test the injectors in the rail for any o-ring seepage before you start bolting down the rails as in the picture below.

Follow these particular words of advice above to the letter! Replace all gaskets and hoses while you are there and clean everything until it sparkles. You will be good for 100K miles.

Check KS and harness. I would replace on general principles as they live at the bottom of the valley of death and you do not want to return soon. Trust me.

[vin27]

Thanks for the great advice guys, I spoke with Chris and he was very helpful too.

By the way, what's the big difference between the Phase 1 and Phase 2 injectors?

I've read about it here on the forums, but didn't see what the big difference was.

On my 1991 Q45, I've had the same injectors in there since it left Japan, it's
got about 185K miles on it now.

I've also got a 1990 300ZX TT, about 60K miles, never a problem
with the injectors.

Now the 91 Nissan Pathfinder my dad has, I think he had
an injector go bad every year for the first three years!

All the best,
Vin

[maxnix]

Phase I are single pintle, Phase II are rotary pintle. The fuel rails are different, or some have shimmed the Phase II with Phase I rails.

[vin27]

By the way, how do you guys pressurize the Fuel Rail
and check for leaks?

I went by AutoZone, the only thing they had was a Cooling
System Pressure Tester. . . I'm trying to figure if there
is something I can Rig up with Bike Tire Pump?

I've got a pretty typical Tool Set, and no
Compressed Air other than a Bike Tire Pump.

All the best,
Vin

[subtle_driver]

I second the DW kit! very nice setup, I converted a 300zx TT from phase 1, to phase 2 and I liked the completeness and the quality of their kit. Thumbs up!

Only thing is the DW injectors are not ethanol compatible, according to personal experience and the sales rep.

[OwnerCS]

I picked up the fuel line pressure testing kit from Harbor Freight. Once I installed the gauge in the line, then I was able to “carefully clamp” the return line and the input line to capture a high pressure point when switching on. It took a couple of tries and some simultaneous clamp and release operations to capture the pressure at the high point. Once captured, it sustained a pressure for hours before bleeding off.

IIRC the BWD injectors are ethanol compatible. I remember Heath doing a bit of research on the subject. For as much as the BWD cost, they ought to be compatible alcohol, jet fuel, you name it.. LOL