Bobo

I posted a thread a few days ago about a P0305 and P0325 code that I threw for #5 cylinder misfire and knock sensor or circuit fault.

The problem turned out to be a fuel injector which I had replaced today. The job is a PITA as the plenum has to be removed.

I am not sure if it is a coincidence or not but the CEL was triggered a couple of days after and about 10 miles after adding Chevron Techron Fuel System Concentrate to about 12 US gallons of gas. I had used Gumout Regane about 11,000 miles previous to this. Given I was coming up to an oil change, I thought I would use some more Chevron Techron but they don't sell the straight Chevron Techron fuel injector cleaner in the bottle in British Columbia anymore.

Is it possible what I used dislodged something hung up in the injector causing it to stick? There was fuel getting to the plug to some extent as a result of the misfire. So I replaced the laser platinum plug, although it only had 25,000 kms (15,500 miles on it).

The owner of the shop also told me that when an injector goes that the others typically aren't far behind. Does this make sense? If this were true, I might have considered replacing the other 2 rear fuel injectors given the plenum was off, but he didn't tell me this until after I paid the bill.

I went with an OEM fuel injector rather than a rebuilt one that I returned to a parts shop.

I don't need a knock sensor, but if the plenum was already off would it be easier to access the ks and change it out?

whiteSE

iTrader: (2)

1. when installing, you could of damaged your injector, but i doubt it. so idk about this one

2. what he said is sorta true. think about it, u have 6 injectors, and they are all the same, and they worked the same as well. so they wear out the same. in this case, one injector went a little sooner then the others. so if u had a pain taking the UIM of, then go ahead and change all 6 right away. you can get injectors on here at a good price. i was selling 6 injectors with 12k on them for $40.

3. if u don't have a "ghost code" for a knock sensor, then i don't see the point in changing it, but to answer your question, yes, it is easier to replace it when the UIM is off. you are going to have to take the LIM off as well though.



hope i helped

Bobo

Thanks.

The reason I am questioning the need to replace the other 5 fuel injectors any time soon is that the car only has 82,600 mostly highway one-owner miles on it and has always run on decent gasoline.

I am hoping that the other injectors last quite some time.


I took back an rebuilt injector that cost $94 plus tax and went with an OEM injector that cost $195 plus tax. I did not want to drive the car any longer in its current condition.

I strongly suspect that the vast majority of 4th Gen owners on this site get a lot more than 82k miles out of their injectors.

I do get the car out on the highway and enjoy the benefits of a y-pipe, so it is not as though the car is babied. I also ran a bottle of Auto-rx through the combustion chamber 23k miles ago in order to clean the engine up and rejuvenate the seals before switching to synthetic oil. I have been running Esso Extra XD3 PAO 0w30 full synthetic for the last 20k miles.

Acesanugal

I have a question... And I suppose this doesn't really count as thread hijacking, considering the problem and the unique way you cannot post a thread until you have x-many posts (Which as a former Rotary forum owner, I completely agree with), I guess I'll ask here.

I've got a '97 SE (Manual, o'course!) with closing in on 200,000 miles. My CEL came on a few months ago when I bought the car. I pulled the codes and originally just had P0174. Cleared the code, did some searching, but didn't think much of it because my gas mileage was around 22mpg mixed. I went through a phase of running premium, simply because it is what's recommended...Then the poor bug was going around and I stepped down to regular. Mind you, this car, before me, had never once been run on premium gas.

Well, as these idiot lights are, the CEL came on shortly after clearing it the first time. Obviously, clearing things out doesn't fix the problem, it just turns that silly little light off. It's been on to this day.

So today, I decided to pull the codes again. I was noticing some light 'pinging' under acceleration between 1,000 and 2,600 revs. Now, this noise is something that disappears 90% when I run premium, so last night I made the decision to switch back to premium. Opinions be damned, *I* notice a difference in the way the car runs and feels between grades.

Codes seen today....

- P0174: Bank 2 lean
- P0171: Bank 1 lean
- P0325: K.S.

Your eyes are not deceiving you, those are indeed two new codes. I've kind of reached a point where I am actually asking for advice/opinions. I never really dove too far into P0174 originally, but now that it's sister code and the K.S. code are being thrown, I'd be lying if I said I wasn't uncomfortable.

I am a Rotary enthusiast and a Mazda guy. The Nissan business is new to me, and diagnostic wise, I'm unable to organize a plan of attack.

Generic K.S. run $22.00 shipped on Fleabay right now, which is cool. But that's also $22.00 out of my pocket. Possible gall stones and the effects from said issue have limited how much I can work until my doctors figure out for sure what is wrong with me; money is tight.

I'm not entirely worried about the K.S.. So long as I run premium gas, it should be fine. If, however, certain forum members here with impressive credentials tell me to replace it, I will. As for the other two codes, I'm stumped. I've been told I've got a bad injector, a dying fuel pump, a clogged fuel filter (Which I replaced, btw... I mean seriously.. It was $2.00!).

I think it is worth mentioning that when I got the car, it had a monumental coolant leak from the ****ty little three inch hose on the back of the I.M. on the driver side. Yeah.. that was three hours of my life slipping on a snowy/icy driveway with it coming down on me like hell that I can never get back.

However, when I put it all back together, the EGR down tube (I guess?) had a little tiny gasket on it that managed to disintegrate into ten thousand tiny dusty pieces. Seeing as it was 15 degrees outside, I ignored it. I don't have to pass emissions here.

That being said, the part worth really mentioning is that the CEL for the original P0174 code illuminated that stupid light not but a few days after it all happened.

I can't imagine that an exhaust leak THAT SMALL could have caused the code to be thrown? If it is, can it have thrown the sister code? And what explains the K.S. code?

Description of the way the car runs and drives...

- Compared to my current FC RX-7, the torque is nice.
- Right around 3,000 revs, the power really pours in.
- Around 5,200 revs, a noticeable drop in power is noticed (Similar to the way N/A FC's are...why take it to redline if it's no longer making peak power?)
- On occasion, it takes a few seconds of cranking (Two or three) before it fires. RARELY do I have to stop cranking, then try again and it fires no problem. Most of the time it fires right away, though.
- I usually get 350-384 miles to a tank.
- Engine burns no oil or coolant, runs at NOT, and uses maybe..eh.. half a quart between 3,000 mile oil changes at the most.

Help appreciated!

Cheers,
-Collin

Bobo

I would be inclined to run the premium gas awhile longer and replace the knock sensor.

I question whether it is the fuel injectors. I am not sure what causes them to run rich or lean and perhaps some one can weigh in on that as I haven't had those codes before.

I know cash flow is problematic for you right now, but I would be inclined to replace it.

I know this may sound like sacrilege but have you talked to a stealership. Don't let them touch your car.

Acesanugal

I don't believe much in the traditional Stealership...

Truth be told, injectors don't really go bad.. They get clogged, fail, or seize from corrosion. Injectors are a common slow-failure item on rotaries. Usually we just send them off to be cleaned and flow-tested before and after to evaluate how big of a problem they were to start with, and to indicate the health of the injector after it's been cleaned. In most cases, Witch Hunter Performance can get them within a few percent of new-performance.

This is why the injectors being a problem with my Maxima doesn't sit too well with me, and it's why I am stumped. The car doesn't jerk, or produce a blunt hesitation throughout the rev range. See why I'm stuck?

Correct me if I'm wrong, but doesn't the Knock Sensor advance/retard timing, essentially affecting the air/fuel ratio that could be causing the lean codes to be thrown?

***Edit*** If I have to, I can afford the generic KS off ebay, but I'd rather not if it's determined that isn't the problem. I have found that you can test the KS with a multi-meter, but it's not a for sure diagnosis. Trust me, dealing with OBDII cars and all these fancy-schmancy electrical systems and sensors etc *really* makes me appreciate my humble 150ebhp N/A rotary engine. :-P No offense.

Bobo

Not sure that I can help you with the ks question.

I read through the thread on highest mileage 4th Gens and there is only a couple of posts that mention any problems with fuel injectors.

I have the old fuel injector. I might take it into a place I found about that will test it, do the ultrasonic cleaning of it and retest it for $25. It does work to some extent as there was gas on the plug that was removed. I replaced the plug although it didn't look fouled and only had 15,500 miles on (NGK laser platinum OEM plug).

As far as rotaries go, I have owned 5 in my lifetime - an R100, RX4, two 79s and an 85GSL-SE. The 85 died two years ago shortly after being talked into an oil flush at a Pennzoil lube joint. I should never have done it. I went on vacation shortly after the flush/oil change and came back 10 days later and couldn't start the car. I got it towed into a knowledgeable shop and was told it was a seal problem. I will never do an engine flush again as I thing it screwed the apex seal.

The vehicle had almost 138k miles on it at the time and I owned it for 58k. I never had a fuel injector problem with it.