Re O2 sensors: "Fed Spec" vehicles have 3 O2 sensors - two "upstream" (before the cat) and one "downstream" (after the cat). There are separate upstream sensors for each cylinder bank - the bank at the front of the engine compartment is "Bank 2" and the one at the rear of the engine compartment is "Bank 1" (because it contains cylinder #1). The OBDII codes will call out the two upstream ones as "Bank 1 Sensor 1" or "Bank 2 Sensor 1" The downstream one will be identified as "Bank 1 Sensor 2." A "Cal (California) Spec" vehicle will have two downstream O2 sensors after the cats; the second one will be identified as "Bank 2 Sensor2."

 

Short update for tonight....

Cleaned MAF and replaced final CKPS sensor near oil filter and cleared codes.

Still hard starting when warm. 2 times today the ignition did nothing. One of the times I gave the clutch a good kick and it started trying again so will look at the clutch interlock relay tomorrow and may check/change ignition switch. Not sure if these 2 problems or related or just coincidental.

Still hesitating, misfiring and running rough. MPG is in the bucket. Fuel air mixture still severely off. Smell of fuel is strong. Getting like 15mpg maybe....

Ugh......getting ready to throw in the towel.

 

OP. You're gonna have to get your hands dirty and open up that Manifold, and the fuel rail. I can't stress enough how much it's an injector problem, and even the Haynes manual says it under the troubleshoot "fuel smell coming from engine bay and inside of car -----> Problems with fuel injection system"


All I can say is, make sure you take off the fuel rail with the injectors first, and place a rag over the opening of the LIM since you don't want ANYTHING falling into the valves. When you are checking the injectors from the bottom, look for the pintle to make sure it's clamped like a 4 prong claw to the bottom of it. If it's missing pieces, or missing some completely, then you've got your problem. It also wouldn't be such a bad idea to make a junkyard run, if it's accessible, and pocket a few injectors since they are pretty small and fit in your pocket.


I really do hope you get this fixed man. I couldn't stand it one day, let alone weeks as I imaging you're doing so right now.

 

Alright I'm all for attacking that project. My question is...

I remove the UIM...then what?

I obviously can't run the car to test the fuel injectors it's covering and the front 3 are at least firing (i can hear the clicking)

So what should I do/look for? Just pull each injector and see if the pintle is there and un damaged? And if it is damaged replace just that or the whole injector?

THanks for your help. You are right I am beyond tired of this.

 

Also, how I would I tell if there was a leakin injector?

 

How does the car drive on the highway? OK? If it is OK, then I would think it would NOT be injector related.

Also, all those ignition fuel system related codes, I remember I got a gazillion codes like that on an old alitma I had which was in bad need of a tune up. The plugs, rotor etc were so gone and I knew it. The car freaked and even gave me a code to replace the entire feul injection system.

I gave the altima a tuneup, plugs, rotor, cap air, etc...all was good after that. So be careful with the codes.

The put-put-put suggests 1 cylinder is really having trouble.....you need to get those plugs you couldn't reach outta there. Modern ignition systems can work your plug to their last and beyond and you wouldn't even notice because the system compensates so well. The fact that your car is put-putting suggest either the coil (which you're already taken care of) or the plugs, and those 2 plugs seem to have been in there waaaaay beyond their lifetime.

Good luck

DW

 

First of all, I apologize for replying late to your quote man. And I'll help you out with you you need.

So after removing the UIM, you can actually check the injectors to see if they spray by just removing the fuel rail from the LIM and somebody cranking the engine just maybe one crank. Don't do more unless you want to get gas all over the place. Oh and yeah, use a lot of rags. It's gonna get messy

If you see that all of them are spraying then I would think that they all work. You can also check to see which doesn't work by just looking at them to see which is "dry" and not smelling of fuel. You can't really mess up an injector though, and they should rarely go out. Only the seals and retainers (pintles) go bad. If you have a voltmeter use it to measure the ohms on the injector. I'll look them up, but if you want to use the FSM, I can also provide you the link for it which is this one: http://www.nicoclub.com/FSM/maxima/

If you do find that one of the injectors is bad, then obviously, replace, but please... make sure that seals that sit on the LIM are facing the right direction. I made the mistake of installing them upside down (they have a ring groove that is the "side up" where the fuel rail sits) and that was causing me to spill fuel after fixing one of the injectors, like there was no tomorrow But if you remember how they went, you'll be good.

If you find that the orange/yellow pintle on some of the injectors is broken or missing, it is most likely the problem that is causing you to lose fuel. I was missing them on 3 at one time, plus 2 failing injectors, and that was no fun at all. I felt like the bay would just blow up at any second but luckily I made it back home and swapped over the 00VI

Word of advice, just make sure you don't lose the injector caps, screws, or seals into the valves. Getting them out is not as hard, but if the valves are open and they fell into it, then I hope they just burn up at startup. And carefully use Vice Grips, if you have any, to remove the injectors. Use a tiny bit of new engine oil to lubricate the seals of the injectors when re-installing them. They make it a lot easier, and you won't crack or break anything. Lastly, install what looks like the "good" injectors in the back of the fuel rail. If one of the front ones fail, at least you don't have to remove the UIM if it goes bad.

Use the FSM like a bible dude. Check the harness and voltage to rule out any malfunction with anything that's electrical, because that's the last thing you want to happen... knock on wood.


Anything else, just let me know dude. And again, sorry that I replied until now



P.S. Try to get everything at the junkyard from a good maxima. You don't wanna spend a lot of $$$ when you can get it for cheap there.

 

Hey brother

Thanks for the lengthy reply. Gonna try to at least check the front 3 injectors tomorrow before work. Went to the junkyard today to kinda expiriment and check out some things before I try them on my own car.

one question

Any ideas on getting the injectors out of the actual fuel rail???

I was able to spin them around but for the life of me couldnt get them out of there or even close.

Thanks again!

 

That's what the vice grips are for. LOL. Try to pinch the square edges of the injector after getting the cap off and slowly twist and rock side to side until they pry out. Make sure that they're not on too tight or you could crack/strip the top of the injector with the vice teeth. Also, wear goggles, or just squint when it finally does pop off since fuel will drip up from it.


Good luck man. And let me know how it goes!

 

Alright here's the update....both good and bad ha!

Pulled the UIM and go right down to it this morning. Pulled spark plug #5 and it was black and drenched with gas after the engine only ran for 25 seconds. Pulled fuel injector and found the pintle completely gone and the O-ring all the way down at the bottom just like you thought. Tip was also cracked. Replaced sparkplug and injector.

Now....

Put everything back together and it roared to life after the first turn of the key....

Unfortunately, it ROARS up to about 3000rpm real quick, then falls down to about 500 and then dies. I can here a LOUD air leak coming from around the IACV and up near the firewall.

On the plus side, I no longer smell gas at all.

So i'm thinking and hoping, maybe I just missed something when I put everything back together and put the UIM back in. Maybe I missed a hose some where.....any ideas are helpful.

Also, anyone know where the Intake Air Temp Sensor goes?? I found mine plugged in and hanging down near the air filter today just floating about.

Thanks again man. I think you hit the fuel injector problem right on the head. Now I just need to get these last 2 gremlins and I think all will be well!

Thanks again and let me know what you think about the current problem.

 

Are you running an aftermarket intake system? If so, you can place the Intake Air Temp Sensor on the filter, at the end where the plastic goes, or if you're risky, place it into your MAF tube, by drilling a hole into the tube itself, the size of the temp sensor. If you still have the airbox, it goes on there, right before it transitions into the MAF.


As for the 3k startup, it definitely sounds like an air leak. You said it dies down to 500 after right? Does it fluctuate? If you want, get a can of carb cleaner and spray around the IACV, TB, Manifold (where the gasket is placed) behind the egr tube (a little hard to get to, but it's also a place for leaks). Also, check to make sure that your hoses are all connected in their respectful places. There are two main tricky hoses that often go unnoticed and those are the one from the vacuum gallery into the side of the manifold between the TB and IACV, and at the bottom one where it connects to the TB. They're small in length, hence why they often are forgotten.


Let me know how it goes again and I'm at least glad you got the injector problem fixed

 

sounds like SBKMax has you covered and is walking you through all the proper steps. Def got a vacuum leak now. Just wanted to comment regarding your p1320 code though, those STI coils are junk, I would start looking for a used set. Also, you can do what the fsm refers to as a power balance test next time to locate the trouble cylinder, just pull a coil harness or injector wire for each cylinder and see which one doesn't make the engine shake worse.

Good luck with the rest, probably just a tilted manifold, or something trapped under it, or you forgot a hose like pcv brake booster etc. Or that stupid EGR gasket slipped off of one of the bolts.

 

I have to agree. even though you can "Listen" to them and they can be running, they may not be spraying corrrectly. my dad and i had a 1990 S10 with TBI, and one of its two injectors was working but not spraying right. It ran like ****. So, check the injectors man, pull em out.

 

pull those injectors out clean/replace needed, replace maf and ignition switch youll be good to go, bet you ten bucks.
my maf went out and even with a clean still no go, replaced and gogo after.
your injectors probably arent spitting right so get that checked, and your starting issue threw the answer to you when you checked the codes. change maf sensor first and see what that does, they tend to screw up after awhile, it causes the put putting
lmk what happens man.

 

Pulled UIM back off this morning. Only thing i noticed was that my dumbass forgot to rebolt the EGR tube.

Fixed that problem, reassembled everything and...

Same problem.

Quieter air leak sound, but same issue. 3k....400....stutter....die.

Thinking in my hurry i dont remember the EGR gasket being there. Could just that missing gasket cause such a bad engine failure???

Also, ii can find any logical spot on the airbox to insert the intake air temp sensor.

Thanks as always.

 

I mean i CANT find a spot for the intake temp sensor. Dont see any empty holea.

Thanks again.

Typing from my phone. Sorry for typos.

 

**bump**

Anyone know if a missing egr gasket would cause these symptoms???

Thanks.

 

FWIW, when I pulled my UIM my car had the same exact symptom "start, stumble, die"....found the EGR gasket laying on the ground under the car (mustve fell off). After putting the EGR tube gasket back in place, the problem went away.

If Maximized98 chimes in he will tell you that too.


So, yes, from my personal experience that could be your problem

 

Another update...


Replaced EGR valve gasket and car is now running and driving (finally!)

Rand and drove perfect.....for about a day......

Car is still running much better and stronger after replacing the bad #5 injector.

BUT...

Now I'm back to the following symptoms

Occasional strong fuel smell in the cabin but not outside the car
Erratic idle at stop lights (600-1500 or anywhere in between)
Occasional stutter or loss of power
Light engine knock at idle
MPG still pretty bad.

No CEL codes yet after 40 miles of driving.

Now leaning toward either the TPS or the MAF (although the MAF checks out fine according to the test procedure in the Hayne's manual) so not really sure....

Will check front 3 fuel injectors tomorrow to make sure none of the O rings slipped off.

Any ideas are welcome of course.....

Stupid gremlins!

 

Hey keep us posted. FIs are known problems just like ignition coils, dash rattles, and EGRs plugged up with carbon. I am fighting a problem similar to yours in everyway.....but it's intermittent and won't stay bad long enough to nail it down. I do believe it's a FI or maybe multiple FIs. I have gone through all the grief of non-OEM coils and that cursed P1320 misfire code...don't buy the $30 junk chinese or polish built coils.
I have no OBDII codes even though it's blowing smoke and skipping and spark knocking.

 

Sorry to break it to you but there is no real way to check the maf. Sure you can check voltage with a multimeter according to the fsm.

But I have personally had bad mafs that still checked out fine via that test. Best solution is to swap with a known working unit if you want to rule it out. Also, splice into the black wire on the maf harness and ground it to the engine bay. I feel like a broken record... Old wiring will kill the 4th gen maximas.

Your diagnostics are good but the multimeter test can be ineffective... The O2 sensor should never cause any car to not start or to run rough. The computer utilizes it only after successful starts.

I say check the basics. Vacuum hoses that are cracked. Any hole in the air intake system. If you aren't stock put it back to stock to rule that out. Damaged wiring, wiring in the harness that isn't giving proper signal to ecm. For example, it tests fine at the sensor but the signal wire to the sensor is damaged.

A shop would do a fuel pressure test instead of throwing parts at it. Did you ever fix the sparkplug that you said was defective?

 

2 Additional symptoms just popped up.....

1. Twice I heard a random squeak like a belt slip from the engine (could be nothing)

2. The Gas light that I believe used to come on around 1/8th of a tank.....now doesn't come on at all....until you run out of gas.

Yea.....guess how I found that out.....

Nice leisurely jog to the gas station at midnight.

Ah....

 

ALright!

I'm 99% sure I've located my last problem.

Looked today and noticed that with the car running, injector #1 is POURING fuel out the top and all over.

Pulled UIM and pulled injector and O-ring on #1 was half missing. Have no idea how that happenned at all.

Went to Oriellys who of course didn't have the right size but close. Well, close didn't work and it's sill pouring gas to to the junkyard I go in the AM.

But i'm thinking that would explain the fuel smell, the terrible mileage, the loss of power, and i'm assuming that losing that much fuel would cause the pressure at all the other injectors to drop too??

Hoping this is it.

And on a side note I got the last spark plug out. The ENTIRE boot had gotten stuck down there and slid around the plug. I couldn't see it. Had to pierce it with a sharpened coat hanger.

Cross your fingers but this may be it.

 

fingers crossed

hope that this is the problem.

 

Fingers crossed as well OP. Sorry I haven't been keeping up with your progress or getting back to you! School got the best of me....

 

I guess that was, since he never replied back :/

 

Alright...

Swapped out cylinder 1 injector with junkyard injector and proper size O ring. No more leak ;-)

Car running better this morning. Still idles erraticly at times, not sure why. Also still a light knock at idle....not sure why. Have only driven it 5 miles to work this morning but so far it's defintely better. But still not 100% from what I can tell.

Idle still occasionally floats from 400 to 1400 or anywhere in between, and at idle it sounds almost like it's stuttering. It's weird.

Will keep you updated as I drive more.

 

^^IACV?