ENGINE MISFIRE/KNOCK ROUGH IDLE <----I KNOW YOU'VE SEEN THIS BEFORE

Post by **djerok** » Sun Jul 29, 2007 7:55 pm

I LOVE MY Q BUT IM SERIOUSLY ABOUT TO DRIVE IT OFF A BRIDGE. RIGHT NOW MY MECHANIC IS PLAYING RING AROUND THE COIL WHILE I PAY $50/DAY TO RENT SOME POS. HE CHANGED THE PLUGS AND SWAPPED A COIL THAT HE THOUGHT WAS THE BAD ONE AND NOW THE ENGINE MISFIRES EVEN MORE FREQUENTLY. NOT THROWING ANY CODES. WHAT IS THE FIX FOR THIS PROBLEM? THIS HAS BEEN AN ONGOING TOPIC HERE IN THIS FORUM FOR YEARS NOW AND STILL NOBODY POSTED THEIR SOLUTION. YOU KNOW THE SYMPTOMS: ENGINE MISFIRE/KNOCK WHILE CAR IS AT A STOP/REVERSE (REALLY BAD IN REVERSE), ROUGH IDLE, NOT THROWING ANY CODES AND CAR STILL RIDES LIKE A DREAM WHEN IM ON THE GAS. WTF IS THIS? FUEL PUMP? INJECTORS? COILS? HELP ME PLEASE BEFORE I GO INSANE. THANK YOU..

-ERIC

Post by **maxnix** » Sun Jul 29, 2007 8:30 pm

First off, we are not blind, so PLEASE DON"T SHOUT AT US. Thank you.

"More Q45 have been damaged by unknowing mechanics." - Q45tech

Please give us a clear maintenenance picture so we can try to understand why some person unfamliar with a VH45DE is tearing through it. Do you even have the FSM?

With no Consult you are up that creek with no paddle.

Post by **djerok** » Mon Jul 30, 2007 3:44 am

I apologize for the caps lock, call it a severe case of frustration I guess. This car is very well maintained. I take very good care of it. I only use premium fuel at all times and I always change the oil on time. As far as bringing this vehicle to my under qualified non-infiniti mechanic, I originally brought this car to the very pricey infiniti dealer and they told me that they couldn't find anything wrong with the car ($100 later). The symptoms started about a year ago and it seems that they have progressed for the worse as the time goes by. It seems that a lot of people are in my situation and there has to be someone out there that was able to get it fixed before just scrapping the car and taking a huge loss. I've spent so much money trying to get this issue resolved and i have gotten nowhere. I'm not familiar with the term FSM so I don't know if I even have it or not. I don't want my mechanic to work on this car and my biggest fear is that he's gonna screw it up. He is trying to isolate which coil is the bad one but I really don't even think this has anything to do with the coils... I'm thinking dirty injectors or possible faulty fuel pump? I'm not a mechanic so i'm not really sure... Someone please help me... Thank you ...

Post by **goody90q45** » Mon Jul 30, 2007 4:28 am

Have you ohmed your injectors? If you're sure you're not getting any ECU codes I'd also suspect the FPCU and/or fuel pump. Q45.org has a good article in the tech help section for grounding the fuel pump to determine if your FPCU is bad. Ohm the injectors first and let us know the readings.

Post by **bullittandy** » Mon Jul 30, 2007 7:03 am

I don't think this is the problem but...

I had the same problem, (97 Q45) and did all the rec services, including BG44K, air filter, pvc etc.

I also replaced the Knock sensors at about this time and the porblem has not shown back up. I am not saying that the K/S fixed the problem, only that the problem went away and has stayed away about the same time that I replaced the K/S. Since K/S fail regularly, replace them without fixing anything else to see if that fixes it.

Yuor car will be a good test for this as your other fixes have not worked and the problem is very noticable. Good luck!!

Post by **djerok** » Mon Jul 30, 2007 9:10 am

I'm going to try BG44K treatment today.... I have a feeling that this problem has something to do with my injectors and fuel system... If this BG stuff is as good as everyone says it is, then it should help a little. I was told to buy two cans, use the first can, then filler up again, then use the second can on the third tank.... I'll keep you posted. I will also suggest to my mechanic to ohm the injectors.... thanks guys....

Post by **djerok** » Tue Jul 31, 2007 2:25 am

Wow this stuff really is as good as everyone says it is. I was put-put-ing before i dropped it in the tank and as soon as I did the treatment is was like night and day. Couldn't believe how quick this stuff works. I haven't felt a kick from the motor yet (i wont say that too loud). I only wish I would have tried this before spending $800+ on coils that prob didnt even need to be replaced. A $18 can could have saved me all that money. I'll keep you guys posted but so far so good. I got another can that i will use again in a few days.... Thanks for the advise...

Post by **Miyabita_Y33** » Tue Jul 31, 2007 1:22 pm

change your oil after your second can. or the proble will come back.

I had the same prob FYI. It came back with no oil change

Post by **maxnix** » Wed Aug 01, 2007 1:59 am

Don't forget to change your fuel filter also. When BG44K works dramatically, it confirms fuel system is or was serioiusly contaminated.

Might want to consider a BG rail flush for superior cleaning.

http://www.bgfindashop.com
Modified by maxnix at 10:47 AM 8/1/2007

Post by **elwesso** » Wed Aug 01, 2007 4:34 am

some interesting information floating around here.

on a G50 the fix is well known and that its the injectors. Dont know how that was missed?

I have a feeling the 44k is only a temporary fix. Report back with the results of the injectors and we'll go from there.

Post by **djerok** » Wed Aug 01, 2007 7:32 am

yea unfortunately the 44k was only a temp fix. As soon as I turned the A/C on, the problem came right back. It isn't as frequent or as violent as before, but it is still there I will keep you guys posted. I'm still only on the first can. I am due for an oil change so I'll deff get that done asap. Should I wait until after I use the second can or should I just get it done asap? The problem still has dramatically improved. Over the weekend I actually had to stick the car in neutral everytime I stopped at a light. Putting it in neutral seemed to minimize the engine misfire. I do also need to change my fuel filter. Does anyone know where the fuel filter is in this car? It was uner the hood in all of my other cars, but i was told that this one was in the gas tank??? I dunno, if anyone has any advise or possible a step-by-step diagram on swapping the fuel filter, it would be greatly appreciated.. Thanks again guys...

Post by **maxnix** » Wed Aug 01, 2007 7:49 am

You really need to get an FSM and study it.

Post by **djerok** » Thu Aug 02, 2007 2:53 pm

i still don't know what that means....

Post by **goody90q45** » Thu Aug 02, 2007 3:37 pm

maxnix wrote:You really need to get an FSM and study it.

djerok wrote:i still don't know what that means....

FSM= Factory Service Manual. Avalable for free download at phatg20.net.

Have you ohmed your injectors yet?

Post by **djerok** » Fri Aug 03, 2007 4:54 am

No, i have not ohm'ed the injectors yet. Im am on my second tank of gas since the 44K treatment and the engine hasn't stumbled in a while. I will chainge oil this weekend and then use another can of 44K. I don't see the need to "study" the FSM. I have no desire to persue a career as a Q45 mechanic.

Post by **maxnix** » Fri Aug 03, 2007 5:05 am

djerok wrote: I have no desire to persue a career as a Q45 mechanic.

Nor to maintain a G50 either, evidently.

Where do you think the answers to your questions about how the engine functions may be found?

Post by **dodiho** » Fri Aug 03, 2007 6:18 am

Maxnix...good reply about the FSM....The pfat site didn't have one for my '99 Q....I just posted my same problems yesterday wanting input from you guys. Where could I buy a good code scanner for my cars? At a reasonable price? I live near you in the Waco area and Appreciate all of the advice and time involved answering our questions! Thanx!

Post by **maxnix** » Fri Aug 03, 2007 7:12 am

Pep boys run them often. Don't get the super cheapy, the ~$200 one will work. Wait for it to be on special, $30 off.

The 1999 FGY33 Manual is on this page. you will need WinRAR to decompress.

http://phatg20.net/modules.php...id=62

The TSB for the FGY33 are many and are only available in complete form from

http://www.nissan-techinfo.com/infiniti/ for a one day fee of $20.

Owner's manuals are free to download there.

Post by **q45VIP** » Sun Aug 05, 2007 5:54 am

goody94q45 wrote:

Does this image apply to G50 also?

Thank you.

Post by **konatown** » Sun Aug 05, 2007 6:39 am

That is for the G50, Q45VIP.

Post by **q45VIP** » Tue Aug 07, 2007 3:16 pm

konatown wrote:That is for the G50, Q45VIP.

Thank you Sir.

m(_ _)m

Post by **silkysmoothyjud** » Sun Oct 14, 2007 7:32 am

Just a note, check the color of your fuel injectors and make sure they have the same color. Injectors will cause hard core misfire issues without throwing a code. The injector would have to be almost totally spent to see if its bad by a multimeter test. I had that problem and it was the cream colored injectors in my car (half were purple, they are all purple now) and a hose, the Pus_Y hose on the plenum, its a bent hose next to the throttle on the plenum, (plenum to plenum hose.) My misfire was so bad from trying to use used injectors, that it caused the water pump to leak out of its hole (related?). If I didn't try to rig it myself, i NEVER would have found the problem...

Post by **Haitian_King** » Mon Oct 15, 2007 10:05 am

Yeah. My car is idling rough. It's really noticeable. Like you see yourself moving up and down. So I took it to the shop and $100 later, I was told it was the #8 injector. So. I bought some injectors from cccpman, and I plan to have it installed this weekend. Hopefully, this will end my Q's bout with Parkinson's.

Post by **maxnix** » Mon Oct 15, 2007 10:13 am

maxnix wrote:The 1999 FGY33 Manual is on this page. you will need WinRAR to decompress.

http://phatg20.net/modules.php...id=62

The TSB for the FGY33 are many and are only available in complete form from

http://www.nissan-techinfo.com/infiniti/ for a one day fee of $20.

Owner's manuals are free to download there.

The phatg20 links to manuals are no longer active. Wonder if they had a word with Nissan or too little bandwidth?

Here is Q45 FSM page for downloads.

http://www.nicoclub.com/FSM/Q45/

Pre-1994 will have to improvise off the 1994 FSM or eBay or retail one, which are now usually bible sized ones that were OEM in each early car.

Post by **Q45tech** » Mon Oct 15, 2007 11:41 am

I have no desire to persue a career as a Q45 mechanic

You better be better trained than the average dealer technican or you will be in serious trouble indeed owning any out of warranty lux-o-sport automobile.

The real money is in diagnosis not mechanical parts replacement..............using the word mechanic today is serious blasphemy to the educational expertise required.

Post by **onelly23** » Sun Sep 30, 2018 12:34 am

djerok wrote: ↑
Wed Aug 01, 2007 7:32 am
yea unfortunately the 44k was only a temp fix. As soon as I turned the A/C on, the problem came right back. It isn't as frequent or as violent as before, but it is still there I will keep you guys posted. I'm still only on the first can. I am due for an oil change so I'll deff get that done asap. Should I wait until after I use the second can or should I just get it done asap? The problem still has dramatically improved. Over the weekend I actually had to stick the car in neutral everytime I stopped at a light. Putting it in neutral seemed to minimize the engine misfire. I do also need to change my fuel filter. Does anyone know where the fuel filter is in this car? It was uner the hood in all of my other cars, but i was told that this one was in the gas tank??? I dunno, if anyone has any advise or possible a step-by-step diagram on swapping the fuel filter, it would be greatly appreciated.. Thanks again guys...

Please i need your help as im currently having the same problem with my fx35. I knocking misfire that happens when i idle at a traffic light, in reverse and sometimes in park. But it gets better while in neutral. Please djerok were you able to fix this fault?

Post by **Q451990** » Mon Oct 01, 2018 12:24 pm

Unlikely you'll get a reply to a 11+ year old post. I'd create a new post in the correct forum that will have better information about your engine. The technology in your '05 FX35 is substantially different than the previous generation engines. If you have OBDII codes available, that will go a good way in helping diagnose your problem.

....edit... I see the FX forum is even slower than this one, so I certainly understand why you posted here. Either way, the FX forum is the best place for this. I'll try to help over there to whatever extent I can.

ENGINE MISFIRE/KNOCK ROUGH IDLE <----I KNOW YOU'VE SEEN THIS BEFORE

ENGINE MISFIRE/KNOCK ROUGH IDLE <----I KNOW YOU'VE SEEN THIS BEFORE

Re: ENGINE MISFIRE/KNOCK ROUGH IDLE <----I KNOW YOU'VE ... (djerok)

Re: (djerok)

Re: (djerok)

Re: (Miyabita_Y33)

Re: (maxnix)

Re: (djerok)

Re: (maxnix)

Re: (djerok)

Re: (maxnix)

Re: (dodiho)

Re: (goody94q45)

Re: (q45VIP)

Re: (konatown)

Re: (q45VIP)

Re: (silkysmoothyjud)

Q45 FSM Download Page(maxnix)

Re: Q45 FSM Download Page(maxnix) (maxnix)

Re:

Re: ENGINE MISFIRE/KNOCK ROUGH IDLE <----I KNOW YOU'VE SEEN THIS BEFORE

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