Q45 Injector Compatibility

[eisbaer]

Hello,

I have been reading this forum for some time, but this is my first post. I recently inherited a 1992 Q45. I’m aware of the basic things that need to be done for this year Q, and the $ involved.

The car is in good cosmetic condition, has 83k miles, but was misfiring. 3 injectors ohm out of the 10-14 range.

I decided to replace the injectors/plugs/hoses/knock sensors, etc.

I’m to the point of replacing the injectors and decided to be the guinea pig and purchase the Q45 injectors sold by Five-o Motorsport on ebay:

Link to Ebay Auction

Before buying them, I asked specifically if they have a color mark or “no color mark” – the reply being that they have no color mark. The injectors on the car have no color mark. They arrived in the mail and appear to be the real deal (OEM, Made In Japan, Nissan Logo) and have the same physical dimensions as the injectors on the car. The problem is that they have a white color mark.

I’ve searched the forums and Googled for quite some time looking for an answer to the following question(s). I’m hoping that someone on this forum can help me out.

It’s my understanding that the model of injector combined with color mark assures compatibility, this being especially important if single injectors are being replaced vs. all 8 (I bought 8). The question I have not been able to find an answer to is what the color mark actually means and whether it’s OK to have a different color mark when all the injectors are being replaced (assuming they are otherwise correct for the car).

Orig injector (model info): 0P31 1705D (no color mark)(I broke this failed injector while taking it out)

New Injector (model info): 0P21 7907D (white color mark/dot)

Will the new injectors work in a 92 Q?

[maxnix]

If you are replacing all eight with new OEM, then no problem.

If the replacement injectors are new OEM, then no problem.

Not replacing the timing chain guides before you ever start your engine, could be a real big fatal problem.

Welcome to NICO.

[Haitian_King]

Hello,

I have been reading this forum for some time, but this is my first post. I recently inherited a 1992 Q45. I’m aware of the basic things that need to be done for this year Q, and the $ involved.

The car is in good cosmetic condition, has 83k miles, but was misfiring. 3 injectors ohm out of the 10-14 range.

I decided to replace the injectors/plugs/hoses/knock sensors, etc.

I’m to the point of replacing the injectors and decided to be the guinea pig and purchase the Q45 injectors sold by Five-o Motorsport on ebay:

Link to Ebay Auction

Before buying them, I asked specifically if they have a color mark or “no color mark” – the reply being that they have no color mark. The injectors on the car have no color mark. They arrived in the mail and appear to be the real deal (OEM, Made In Japan, Nissan Logo) and have the same physical dimensions as the injectors on the car. The problem is that they have a white color mark.

I’ve searched the forums and Googled for quite some time looking for an answer to the following question(s). I’m hoping that someone on this forum can help me out.

It’s my understanding that the model of injector combined with color mark assures compatibility, this being especially important if single injectors are being replaced vs. all 8 (I bought 8). The question I have not been able to find an answer to is what the color mark actually means and whether it’s OK to have a different color mark when all the injectors are being replaced (assuming they are otherwise correct for the car).

Orig injector (model info): 0P31 1705D (no color mark)(I broke this failed injector while taking it out)

New Injector (model info): 0P21 7907D (white color mark/dot)

Will the new injectors work in a 92 Q?

Dunno. I never bought any of those. The ones I bought were pulled from a Q.

Good job on the Q. My 92 had 83k on it when I bought it. At about 92 and change now.

When I needed to replace an injector before, I was also confused about the colored dots. From what I could tell, I don't think they meant anything. I'd love to know the point of them though.

While you're doing the injectors and stuff, you might as well do the chain guides. I was able to go to 91k with the plastic guides intact, but it was a terrible experience. You'll worry with every crank.

[Q451990]

Great first post! Talk about a long-term lurker... almost a year since joining!

I believe the color mark had something to do with the spray pattern. I think the idea was to match the pattern across all cylinders as the ECU trims the injector pulse width on each bank...so it was beneficial to have them all with a similar spray pattern. I don't think the ECU has the ability to adjust each cylinder, and wouldn't know what to do anyway with one O2 sensor per side. At least I think that's the theory.

As you suggested, replacing all eight makes it a moot point. I'm glad to hear that the auction appears to be the real deal! When I had injector failures on my old Q, I replaced one - then had another failure in a couple of weeks. I decided to replace the other 7. Plenum removal is just too painful to repeat on a regular basis.

This was in the late 90s long before NICO, and probably even the old Yahoo board - so I don't think I even knew to ohm test them. They were probably just clogged. My first replacement round was with Python remanufactured units - and one or more had a bleed-down problem that caused minor flooding and hard starts after a hot soak. About six months later I bought 8 new OEM units - which looked like the ones you bought - with the purple tops.

So anyhow, good luck with them! Please keep us posted on how it all works out! Now that ethanol is here, I'm sure mine are going to be on the way out too... Oh, and are those new o-rings in the pic. included in the auction?

As far as advice - remember to lubricate the o-rings and pressure test the rails before reinstalling them. A leaky lower o-ring will can cause flooding and potentially hydrolock the engine. A leaky upper will just cause leaking out of the top of the rail. Oh, and I replaced the OEM easy-strip philps-head screws on the rail caps with hex heads - apparently that is (was) standard operating procedure at Infiniti of Scottsdale and they had them on hand. Oh, and you might as well check/replace your knock sensors and their subharness, and the hoses and gaskets under there while you're at it.

Good luck and welcome to NICO!

Heath

Modified by Q451990 at 2:40 AM 4/26/2008
Modified by Q451990 at 2:43 AM 4/26/2008

[eisbaer]

I want to thank you for your thoughts on the color mark question. You gave me the confidence to try the injectors.

I'm pleased to report that the job is done, the injectors appear to fit the application, idle is smooth, no apparent leaks, and the car will now shift out of 2nd gear (Upon reassembly, I initially left an -apparently- important connector unplugged).

It was a huge job, but having all the hoses on hand made it possible to complete the work in about 14 hours (over several days).

I also want to thank the many people who have contributed repair documentation over the years. While there are always unique pitfalls (where did that egr gasket go?), there is enough knowledge to make diagnosis and repair possible for mid-level novice mechanics.

Right now, I would say that the injectors are a good buy. I will revise that assessment and let you know if anything goes wrong.

Best Regards NICO

[Q45tech]

14 hours? It took less than 2 hours to replace 1,3,5,7 injectors with new units. Fortunately the hoses were all new from last summer.

Practice will make you much faster assuming you have air tools.

[eisbaer]

Great first post! Talk about a long-term lurker... almost a year since joining!

I believe the color mark had something to do with the spray pattern. I think the idea was to match the pattern across all cylinders as the ECU trims the injector pulse width on each bank...so it was beneficial to have them all with a similar spray pattern. I don't think the ECU has the ability to adjust each cylinder, and wouldn't know what to do anyway with one O2 sensor per side. At least I think that's the theory.

As you suggested, replacing all eight makes it a moot point. I'm glad to hear that the auction appears to be the real deal! When I had injector failures on my old Q, I replaced one - then had another failure in a couple of weeks. I decided to replace the other 7. Plenum removal is just too painful to repeat on a regular basis.

This was in the late 90s long before NICO, and probably even the old Yahoo board - so I don't think I even knew to ohm test them. They were probably just clogged. My first replacement round was with Python remanufactured units - and one or more had a bleed-down problem that caused minor flooding and hard starts after a hot soak. About six months later I bought 8 new OEM units - which looked like the ones you bought - with the purple tops.

So anyhow, good luck with them! Please keep us posted on how it all works out! Now that ethanol is here, I'm sure mine are going to be on the way out too... Oh, and are those new o-rings in the pic. included in the auction?

As far as advice - remember to lubricate the o-rings and pressure test the rails before reinstalling them. A leaky lower o-ring will can cause flooding and potentially hydrolock the engine. A leaky upper will just cause leaking out of the top of the rail. Oh, and I replaced the OEM easy-strip philps-head screws on the rail caps with hex heads - apparently that is (was) standard operating procedure at Infiniti of Scottsdale and they had them on hand. Oh, and you might as well check/replace your knock sensors and their subharness, and the hoses and gaskets under there while you're at it.

Good luck and welcome to NICO!

Heath

Modified by Q451990 at 2:40 AM 4/26/2008

Modified by Q451990 at 2:43 AM 4/26/2008

Q451990 - Thanks for the advice.

I lubricated the o-rings and used channel locks combined with the injector "cap" to pop them in straight down. I pushed the lower o-ring into place in the rail before inserting the injector. I also pressure tested the rail by leaving the rail elevated, hooking up all the fuel system components and switching the car to "ON." Just to be sure the fuel pump had been on, after turning the car off, I covered a fuel line connection with a paper towel and disconnected the line. Pressurized fuel came out, leading me to believe that the test was valid.

I replaced the KS and harness, along with as many hoses as I could identify, injectors, injector harness, pcv valve, temperature sensor, air filter, fuel filter, spark plugs, ...laundry list. Can you tell that I don't want to do the job twice?

[eisbaer]

14 hours? It took less than 2 hours to replace 1,3,5,7 injectors with new units. Fortunately the hoses were all new from last summer.

Practice will make you much faster assuming you have air tools.

OH Air Tools (and practice)

My father now has air tools, and I used them for the first time recently. Upon returning home, I started looking at Sears and then moved on to Craigslist in search of a good value compressor that could run the tools I might want, and not get me run out of the neighborhood. I didn't buy air tools to do this job because I felt that I could really mess something up by moving too quickly (I'm no technician -- light years away).

I'm going to get dinged for things out of order, but I will preempt. I just got the car (drove it from RI to NC). Chains guides are #1. The problem with dealing with #1 first is that I want T3 to do the chain guides and the car was misfiring so badly that I was uncertain that it would make it to T3 without damage due to misfire (I have no idea if this is possible).

Which T3 location should I make an appointment with and what's the time required for the job? Alternatively, if the consensus is (and it is) that I'm foolish to start the car at this point, is there anyone in NC qualified to do the chain job?

[Q451990]

I would think you want the T3 at S. Cobb - assuming Byron is still at that location. He's the one that replaced my guides - and probably Q45Tech's injectors in 2 hours. Amazing how the learning curve works on these cars!

Anyhow, I think in the absense of a verified good tech. in NC, you run a risk of a botched job that is at least as likely as having your engine crater on the way to ATL. And I doubt towing it that far is an option. I would just avoid driving the car until you can make the trip - and book it as soon as possible!

Do you have a Harbor Freight nearby? I find that their tools are affordable and pretty good for ocassional work, but probably not so much for heavy duty daily trade work.

Heath

[Haitian_King]

OH Air Tools (and practice)

My father now has air tools, and I used them for the first time recently. Upon returning home, I started looking at Sears and then moved on to Craigslist in search of a good value compressor that could run the tools I might want, and not get me run out of the neighborhood. I didn't buy air tools to do this job because I felt that I could really mess something up by moving too quickly (I'm no technician -- light years away).

I'm going to get dinged for things out of order, but I will preempt. I just got the car (drove it from RI to NC). Chains guides are #1. The problem with dealing with #1 first is that I want T3 to do the chain guides and the car was misfiring so badly that I was uncertain that it would make it to T3 without damage due to misfire (I have no idea if this is possible).

Which T3 location should I make an appointment with and what's the time required for the job? Alternatively, if the consensus is (and it is) that I'm foolish to start the car at this point, is there anyone in NC qualified to do the chain job?

I'd like to say, (I've already donned my asbestos jumpsuit) that you might be able to get to T3 in good shape. Most of the strain comes from cold starts, and with the warmer weather, maybe it'll help. You're at a fairly low amount of mileage, but even then, it's not a given.

If you take the front cover off, you'll be able to at least give the current guides a once over and check for any sort of hairline fracture or (god forbid) missing pieces.