JvG

Your have an AIR LEAK through the ripped injector O rings!!!

the injector is working just fine. So no codes.

Famairize yourself how the ecu compensates for air leaks.

Did you or did you not oil the O rings before installing them.

JvG

You STILE dont understand . There is an AIR LEAK between the injector and the head. The AIR is going through where the ripped or distorted O ring should be, but isnt.

The ecu responds to the leak by adding excess fuel.

if you had the 22 dollar Amazon BAFX scanner I reccomend, your phone would tell you that the mixture is WAY too rich.

maxima297

Faulty parts don't always throw a fn code! Case in point, the MAF does not always throw a code, but will be the cause of several symptoms. But hey, you "rebuilt" your engine, so you CLEARLY know what you're talking about :eyeroll: your car is throwing classic misfire symptoms (HELLOOOOO P0300!) ffs but you're thicker than the wall we are banging our heads against trying to explain common sense automotive repair to you.

Have fun continuing to eff your car up, cuz you'd rather argue than properly diagnose the poor thing, or fix the little mistakes you and your "mechanic" made. Oh and about the rust in your mirror? Yes, that IS normal, especially here in the rust belt. I don't know why you're shocked. Then again, I don't know anyone who would drop 10k on body work/complete paint job for a car that a) is a daily rust belt car and b) isn't even mechanically sound.

maxima297

Did you even replace the spark plug tube seals while you were "rebuilding" that engine? How about some rtv with the VC gaskets?

JvG

This member is telling you that the valve cover needs to be installed correctly. Or air will leak though the gaps. The ecu would enrich the mixture to compensate for that leak as well..

max ride 41

iTrader: (4)

i'm tired of arguing with you guys. i've done multiple scans and yes rtv was used upon install of new valve cover gaskets. i'm not going to yank all the injectors off the motor to check the o rings, that's ridiculous. i'm not a kid here guys, been around cars a long time, injectors are practically NEW!! tell me why the master tech at nissan didn't mention anything about the injectors?? he said coils and vacuum leaks. why is it not possible that a fpr that's original (24 years old ) is bad? the engine wasn't rebuilt, just had a lot of work done to it, period. i would love to have 1 of you guys see the engine and hear it run, it's almost finished. it actually runs pretty good except for the hesitation and low throttle as stated.

JvG

You refuse to do the very thing which will probably fix your car.

You have a massive vaccuum leak.

You can chase your tail till the cows come home, but your car will continue to have its problem till you sell it from frustration.

While the new owner will fix this problem inxpensivly and then have a good car.

I've been working on cars since 1971. I know more than you do.

You tried to do it your way. Now try mine.

CS-AR and Wizard are very respected membets of this board. They say pretty much the same thing.

From now on, I'll just post a chirp, chirp, chirp as I watch you flounder around still more. It seems that all other members have given up trying to help you as well.

JvG

Oh gee, the Nissan tech said vacuum leaks.

Imagine that.

The same vacuum (air) leak which I'm trying to have you fix.

JvG

Again , did you oil the O rings? If yes, the problem is probably elsewhere.

But if you did NOT oil them, you have ripped o rings which create a vaccuum leak.

We are tired of arguing with you as well.

You are not willing to respond to direct questions, or to listen to reason.

maxima297

It's pointless. Let him continue firing that parts cannon. Honestly, I do hope he figures it out soon because it does suck not having your car run right.

Quickywd01

iTrader: (16)

Maybe he can spray something around suspected vac leak areas because then you don't have to pull the injectors out to make sure they're leaking vac. I've never tried that with injector o-ring leaks but it should work like any other vac leak.

JvG

Yes he could. Water or other fluids would get sucked in.

an unlit propane torch head held very close to a leak would result in an increase in engine speed.

max ride 41

iTrader: (4)

so, started it up tonight and fuel smells strong out of the exhaust. first time i've smelled it in 2 weeks. wtf? i've never had a issue like this ever before with this car. i already told my mechanic we're swapping front 3 injectors next week and checking the rears. by the way jvg, he did oil up the o rings for the back 3 when he put them in as well as the front 2 he did this year as well.

JvG

Ok.

Since the rear injectors are new and the seals were oiled when they were installed, they are no longer likely to cause this issue.

​​​​​So that leaves the front injectors.

Or another possibility is indeed the fpr.
I would remove it's vacuum line. If gas drips out, or if it smells like gas, it's defective. If not, it's good.

You also want to think about getting a proper scan tool such as the one I mentioned. It saves a lot of guess work, and expense.
The scanner would show a rich mixture.
It would indicate a vacuum reading as well. Low vacuum means a leak.
​​​​​

I'm trying to save you from doing extra work next week.

Which is why I asked repeatedly whether or not the injector O rings were oiled.

max ride 41

iTrader: (4)

location of fpr?? if you don't think i beat my head against the wall checking everything twice your crazy. i do appreciate it, sometimes it makes no sense how they are failing and relatively new throwing no codes and no gas smell. it's driving me nuts.

JvG

it is in the fuel rail. Has a two thick rubbet hoses attached to it for gasoline. And a thinner hose forv vaccuum. It looks kin da like a flying saucer.

its located close to the rightmost injector when you stand in fronthe of the car.

Do a search on the forum for photos.

max ride 41

iTrader: (4)

so, my mechanic tried to do a fuel pressure check and his kit didn't have a fitting small enough to do the test. so, on to the injectors, unplugged the front 3 and got a good reading with the ohm meter so i know the rears that are new are fine. we took it for a test drive and it stalled twice and was bucking at around 40 to 60 mph. i saw where the fpr was, looks relatively easy to do. problem is, how do i know if it's not the fuel pump? which should i replace first, they both have similar problems when failing/going south. symptoms still are, stalling, some fuel smell out of the exhaust, bucking at certain speeds. as i was driving it through town at low throttle it stalled at 2 different lights like 4-5 times each after driving a few miles ( like 12 ) so i parked it and let it cool off and after 3 hours of starting running the heat and turning it off it got me home no problems.

JvG

It's probably best to take the car to a different mechanic. One who can finally do an accurate diagnosis regarding what is wrong with your car.

You have been throwing parts at it. That gets expensive.

You can repair the car yourself once you know what the story is.

I can't figure it out anymore.

Best wishes... I know it's frustrating.

Turbobink

iTrader: (2)

I'm still calling injector failure ...

You can't be assured your injectors are in good operating condition simply based on the fact that the injectors are getting good/adequate electrical input.

It's the physical/mechanical aspects of the injectors that typically fail ... a failed O-ring or broken or missing pintle cap aren't going to result in an out of spec. ohm meter result.

Your recurrent fuel smell from your exhaust is a clear sign of a failure and your drive-ability issues only reinforce that in my mind.

Regarding your FPR ... pull the small diameter vacuum hose off of the FPR nipple. Is there raw fuel in the hose of is the inside of the hose or is the nipple wet or moist with fuel? If so, the FPR has failed.

max ride 41

iTrader: (4)

no raw fuel, but the hose had white corrosive looking crap in it and was probably the original hose so he replaced that.

The Wizard

iTrader: (43)

Beat me to it. Was gonna post the exact same thing.
As stated by others, you need a better mechanic that truly knows how to rule out suspect parts.

Turbobink

iTrader: (2)

These guys (mechanics), like WWII veterans, are becoming more and more scarce, and it's a damn shame.

There are plenty of "techs" out there that can hook up a scan-tool and do those things their windows-based program tells them to do, but when it comes to truly diagnosing issues based on operational symptoms ... it ain't happening anymore.

JvG

Yes, I've noticed that.

I'm 64. My cars had no computer controls of any kind. All the diagnosis I did was based on symptoms alone.

That background might explain why I refer to symptoms on this forum.

My first car with an ucu was a 1973 Volvo.
All the diagnosis to its fuel injection was based on symptoms and a volt ohm meter. It was not even Obd-1.

The 1996 Maxima I drive was the first one with relatively modern Obd-2.

max ride 41

iTrader: (4)

yeah, no $hit. i tried to find another shop to work on the max and they all say it's too old, too big a can of worms and i was almost hung up on by one guy. f'in sick of this ****, but i've never wanted to get something fixed more than this damn car for some reason. had her for almost 14 years and have fixed everything that would cause it to run bad/rich. 2 things i'm leaning on are the fuel pump and a fuel pressure regulator because they can both cause lean or rich operating problems and my plugs are black with dry soot ( new ). i am asking for a few op to chime in and with no codes tell me that with stalling after she warms up and stalling multiple times monday night which part should be replaced first. after she sat for awhile she started up, i adjusted the idle and she ran fine going home with barely a stutter and no stalling.

JvG

We have asked you to remove the vacuum line from the fuel pressure regulator. Does that line smell like gas, or does gas drop out.

Please report back.

Another thought.... is your air cleaner relatively clean, or us it filthy.

Turbobink

iTrader: (2)

So if we went ahead and bought you new set of fuel injectors, would you actually install them?

Rit

iTrader: (3)

GoFundHim !

max ride 41

iTrader: (4)

they are brand new, no codes, no gas smell, clicking away normally. do you really insist that the injectors are bad? i would love to try doing that, but it's labor intensive and i honest to fuking god dont' think it would change anything. you wan't to buy them and send them over, i'll put them on, but plugs turning black has never happened on this car before because of a bad fuel injector or 2, just saying.

max ride 41

iTrader: (4)

removed the vacuum line, had some white corrosive looking stuff in it and it was soft so we just replaced it. but no gas smell or gas dripping out. i am going to clean the air filter today, it's a little dirty, but not horribly dirty.

Turbobink

iTrader: (2)

That's not what you've been telling us, as recent as post # 57, i.e yesterday.

JvG

I asked him to check for the presence of gasoline or vapors in the vacuum line which connects to the fuel pressure regulator. Evidently it's not leaking there.

The gas smell which eminates from the tail pipe would mean excess gas. He mentions that the plugs all have fluffy carbon. So the whole engine is running rich.

I also asked him to buy a scanner such as the BAFX scanner sold on Amazon for 22 dollars. It communicates with a smart phone. It reads fuel trims. This would let us know what is going on.
But no response......

Some injectors have been replaced. The O rings were lubricated.

The fuel pump is doing its job. It provides lots and lots of gas.

I'm curious about the fuel pressure regulator.
Perhaps the fuel pressure is too high. That would explain the black fluffy deposits on all the plugs as well as the smell from the tail pipe.

​​​​​​

​​​​​

Turbobink

iTrader: (2)

I'm in no position to debate whether injector's have been replaced.

However, based on statements made in this post (https://maxima.org/forums/showpost.p...4&postcount=37) I do question whether they were installed correctly.

One thing I'd personally encourage you to do max ride, is to pull your front 3 injectors (those have not been recently replaced, correct?) and have a look at they're condition ... these can be removed without much hassle.

JvG

He has stated that oil was used on the O rings when they were installed. It's still possible that there were installation errors. I'm thinking that the gasket between the lim and uim might not be installed properly and has an air leak. That leak, if any, would cause the ecu to inject more gas to all the cylinders. That would explain the black fluffy deposits on all of the plugs.

Yes, I second the concept of removing and checking the front injectors. Oil the O rings when re-installing.

We want this done mostly for the process of elimination. We want to confirm that certain items function as they should. Then we can assume that the problem is elsewhere.

JvG

Maxride,

please read the post about a split boot which connects the throttle body to the maf.

the member is experiencing fluffy black so it on all the plugs. Just like you are.

a split boot, or one with loose clamps will have air leaks. Which the ucu will cope with by injecting excess gas.

please check the boot, then tighten the clamps.

before you do that thiugh, see if the clamp's are tightened fairly firmly.

Sometimes it's the little things like that which we overlook.

max ride 41

iTrader: (4)

ironically, my mechanic did mention a small split in the boot. i shrugged it off because i just replaced it 7 months ago!!!! the clamps i'll check cause he probably took those damn things off so many times lately that that caused a split in the boot. still have to clean the air filter as well, been busy.

JvG

You might have found your problem.

hey, you mentioned that you want to clean the filter.

is it a K&N filter?

max ride 41

iTrader: (4)

yes

JvG

I have one as well. I've used it for 110k miles with one cleaning.

People have experienced trouble with those if too much oil is sprayed on.

The oil can coat the wire in the maf. Once that happens the ecu won't get accurate information about air flow. That could mean too much gas in the mix, or not enough.

You might want to buy a paper filter for now. Also clean your maf.

keep the k&n. You will want to put that back once your car runs right.

I'm trying to eliminate all possible variables one by one.

max ride 41

iTrader: (4)

had a k&n since 11 years ago, i know over spraying can clog up a maf. i'm just cleaning it and replacing the boot if necessary. it looked kinda dirty last time i looked at it ( last week. ) not driving the max right now cause i'm waiting till i have a chance to replace the fpr and i won't do that until i check a few things.

max ride 41

iTrader: (4)

so, replaced the fpr today, it helped because i smell no more gas out of the vents or under the hood. got a code p0505, iacv, touched the terminals together and still there after we reconnected the battery. started the car, took it around the block, got on the highway and she ran great until she warmed up and i got off and she stalled at the light. so, all the symptoms lead to a fuel pump which is next. and the last thing i will do to this car. this doesn't fix it i quit.