AcuraLegend

!!!UPDATE!!!


So after replacing coil 4 last night, I FINALLY got rid of the random misfire codes, and additionally found out that I had a cylinder misfire on 4. I switched the coil from cyl4 to 6, and it jumped. P0300 and P0304/6 . I also tested my throttle body by doing THIS:

-Removed air box
-Disconnected Throttle Body harness
-Put the car in gear
-Depressed accelerator & wedged it down
-Watched Throttle Body Valve open.
-Not profit


I still have a slightly rough idle, but no more codes. I drove about a hundred miles so far and there's no code. I might add a new fuel filter, and see how it goes. I could still have some fouled injectors, but I'm done messing with this car for a week or so!

To fix it all I did:

-New intake gasket
-Replaced PCV Blowby gas hose
-Replaced PCV vent hose (rear)
-2 new [OEM] coils
-Cleaned throttle body
-Cleaned MAF
-Tested/cleaned IVT solenoids
-Tested/cleaned/inpspected crank sensor


::ORIGINAL POST::

Been fighting a P0300 code forever...made few threads already, and the sugestions were promising, but nothing has worked

The obd scanner I got on amazon showed up, but it's not bluetooth! I ordered a bluetooth one will be here saturday.

This is what I did yesterday

1) Replaced UIM gasket
2) Checked/cleaned crank sensor
3) Replaced blowby gas hose
4) Replaced rear (pcv?) hose

I noticed that I havea pretty bad oil leak where the transmision meets the engine. Could this be caused by the infamous crank pulley? Or crank seal? Would either one of these cause a bad misfire?


I'm out of ideas. I dont have any idea what to check next.

I'm pretty sure my plugs/coils are fine. I'm not missing under acceleration, only at idle. And I've replaced them all. I did a coil test, and unplugging the fronts while it was running didnt have any affect

Maybe the next thing to check is fuel injectors?

Child_uv_KoRn

iTrader: (7)

I can't remember, you did the IVT solenoids?

AcuraLegend

I did. I got them both off, and removed the bolt that got it out of the metal housing. The housing was pretty clean, but the solenoids were full of oil. I tried to get them to acuate, but couldn't. Neither one. But I dont think I was getting them power properly.

I connected a lead from my battery, and stripped one end and applied it to both pins on the ivt connector. Nothing happened - with wither motor.

But I did clean them

I noticed that I havea pretty bad oil leak where the transmision meets the engine. Could this be caused by the infamous crank pulley? Or crank seal? Would either one of these cause a bad misfire?

Child_uv_KoRn

iTrader: (7)

You sprayed the solenoids out profusely with brake cleaner? Yeah, they should actuate, so I'm not sure what's going on there. I doubt both would quit working, BUT I have seen two on engines that we were swapping that were stuck from from sitting a while (took awhile to figure that one out lol).

That's the rear main seal leaking. It doesn't matter.

I would swipe some solenoids from the junkyard or find a local member to swap you, so you know you have two working ones.

AcuraLegend

I was going to eat some turkey, and be thankful for some things (like this site, and members like you - hahahaha) then make a ground, run my + lead from the battery again, and try once more.


My last thing to try later today is the rear coils. I was going to swap the fronts with the rears, and see what happens.

I'm also wondering if my throttle body might be the culprit. Shouldnt I be able to depress the throttle (with the ignition set to 'on') and see the valve open/close? I was going to remove the airbox again and see if its opening. If not, well maybe that's it!

Child_uv_KoRn

iTrader: (7)

Yeah, it's worth a shot.

On the one we were messing with it didn't throw an IVT code for a long time. Try rescanning and see if it threw another code?

I don't know

AcuraLegend

Im almost 100% certain my problem is in my intake/vacuum system.

This car reminds me SO much of my bimmer. Variable intakes are GREAT! when they work....

When they fail, well, as we all know, its a ***** to track down. Without a VANOS to point to, I'd say the maxima is a litte more complex.

This is going to sound dumb - but could this be a bad fuel filter? I dont think my symptoms would be this extreme, but a bad filter/air in the fuel system might cause a misfire, right? I'm still getting a knock sensor code, but my thouhgt here is that with the knock being so bad, the sensor is basically staying open the entire time, causing a voltage condition. Is this plausible? If it is, wouldnt that point to a bad ecm?

I was going to pull my plugs also, and inxpect them. They're a wekk old, so they should be super clean. If they're gunked with oil, I might consider replacing an injector or 2. Good idea, or no?

My code reader i got from amazon wasnt bluebotth! It was marked as bluetooth on line, but whenI got it here I cant pair it. I ordered a real bluetooth obd scanner and bought car gauge pro. The new OBD2 scanner should be here Saturday. I'm curious to see if any codes changed.

george__

iTrader: (1)

Don't feel bad OP.

My 02 bought in 2013 has been a total lemon too

Child_uv_KoRn

iTrader: (7)

I haven't seen that condition with a KS, but I guess it's possible if it's running terrible enough.

I'm sure the plugs have some deposits on them from the bad idle, but it's not like they can go so bad to hurt anything at this point.

I would think a vacuum leak that bad would make it miss when revving up and be audible.

AcuraLegend

Well it is kind of mssing on acceleration, now at least. But I dont hear any leaks when I rev it and lsiten in the engine bay...


So what I just did was this:

Put the ignition into 'on' (without turning on the car)
wedged the accelerator pedal all the way down, removed the air intake, and exposed the TB.

The valve doesnt move at all. I don't know if the engine has to be running for the valve to move, but I dont think it does.

So with all that - it looks iike my throttle body is not opening. DO I need to have the car on (engine idling) to view the valve open/close when depressing the pedal?

AcuraLegend

I got my i35 with 38k on her. 2nd owner, from the dealership it was originally bought from. I'm at 199000 now. I have ALWAYS been meticolpous about maintnenace. This car has been extremely well taken care of, up until I started having this misfire in Jan...

I used to have it serviced at the dealer, but they changed their service team around and really just went to ****. I had a good indy shop for a while, but me and my mechanic there had a business disagreement (over my bimmer actually) and I've been trying to find someone competent enough to fix it since. This most recent mechanic was SHADY AS HELL - so I finally gave up and decided to fix it myself.

The car has given a mea few problems over the years, but after putting 160k on it in 9years, I wouldn't say it's a lemon. It just needs some TLC from someone who knows the vehicle. I know a lot about the vq35de , but this whole thing is teaching me more.

These cars ALL have problems with misfires and rough idle and intake issues at this age. It's a 12year old car, I've put a ton of miles on it - and it's been several years since the dealer has touched it. They suck.

I DO have a few nissan dealers here in SA. I'm thinking of taking it to them, explaining what I've already checked and see if they can ID the problem. I don't WANT to, but I'm getting close to the end of what I can do to troubleshoot.


I *REALLY* hope it's my TB. It would make a lot of sense if my bonehead mechanic cleaned it in a traditional sense, and all my problems ahve ben related to that since I fixed the coils/plugs a while ago.


I love my i35. I'd never call it a lemon. The VQ35de is a WEIRD engine. Add the variable intake, and well it just gets "challenging" to diagnose and fix...

george__

iTrader: (1)

^
Hmm maybe they need more loving and care than average car?

I just find fixing stuff on these cars are a PAIN and these cars aren't even considered high end. Maybe your Infiniti though but it's basically a Maxima

Child_uv_KoRn

iTrader: (7)

That's why I keep saying junkyard, man lol. You can grab everything off the top and start swapping parts.

AcuraLegend

There arent any yards that have any 5.5gen max/i35 in my area.


Austin might, but its a drive....last time i found one in a yard in atx,it was stripped bad.

Ill see if i can junkyard dive this wknd if I could pinpoint it to a certain part.

Thanks for all your help!

Bronxboi5

Well for misfire it was my injectors... 2 were bad

AcuraLegend

my i35 is a 5.5gen maxima. Literally no differene at all,except the body panel and trim.

They don't need much TLC per se - but they do kind of require some sophistication and understanding how the variable intakes work.

A lot of it is the same as a BMW. Not completely, but pretty close.

AcuraLegend

Did you ever get any cylinder codes? Right now I'm just getting p0300 - which is random misfire. I was thinking injectors too, but I'd think I'd get a cylinder code for the injector(s).

nestorlugo

iTrader: (11)

There's a few around here(dallas Arlington Area) I called around for ya and found several candides, the cheapest tb can be had for $150 ...but a local yard has a location in Waco and he shows they have one for $125 w/exchange...

Also if you run into a few 3.5 engines is never a bad idea to grab all sensors that you can find that way you don't need $100+ to see if the cam or crank sensor is indeed faulty or bad, and one can't never have too many coils or injectors

AcuraLegend

Thats super dope of you man, thanks!

Yeah I when I had the problem initially, a coworker of mine found a infin in the austin area, and we went and pulled the engine management harness, I got 4 coils, and some cam sensors. I've used all of em now


I found a reman one from a parts house here. $164 w/ $40 core. About to go pick it up I think.

Child_uv_KoRn

iTrader: (7)

That sounds outrageous. I can buy a 7th gen TB for 100 from overpriced junkyards on the phone lol

nestorlugo

iTrader: (11)

Do it for peace of mind(from prev mechanic),just make sure you got good Warranty this should be the deal breaker...is not that bad really for that price...Take Canadiens into consideration ....



Or nah!

.......

clive

The variable intakes are opening on the TB? If not, remove the engine cover and check that the rubber vac hoses are in one piece. Mine had rotted away.

george__

iTrader: (1)

I'll sell my stock tb for $100

AcuraLegend

I'm not sure I understand your post. You mean the solenoids?

AcuraLegend

I'll probably take you up on that. I'll PM you

AcuraLegend

I'm a dolt. I overthink way too much, then I remember something simple and wanna slap myself


www.car-part.com

They have one at a local salvage off of a g35. Its the same TB, and it's only $60. They're closed today, but I'll go pick it up Monday after work.

I REALLY hope it fixes my problem. Will update!

george__

iTrader: (1)

Good luck

AcuraLegend

So my BT OBD scanner got ere and I got it working with car gauge pro....


This is interesting:

-I did the ignition and airflow live tests, and was getting airflow and steady voltage across the ignition
-I cleared my existing codes
-I did the air re-learn procedure

I turned the car on, and started revving. At nearly every rev-cycle, I would get a SES light, and then it would go away. My lights have always remained on.

-So I checked the code. Cylinder 4 misfire. Thats freaking weird, but ok.

So I used the cylinder deactivation setting in the software, and disabled each cylinder. Of course, 4 had no affect. When I would disable any other cylinder, I'd get the violent idle I'm used to.

So I'm going to go switch the coil and injector on cylinder 4 and see if it jumps. If so, then maybe that will be it.


I can say that with cylinder 4 misfiring, the car is running better. Maybe I wasnt doing the air learn procedure right with the pedal dance - and doing it via the app tookcare of that, and now i just have a regular ol cylinder misfire (aftermarket coil probably).

nestorlugo

iTrader: (11)

Ooooh!!.......Nice good luck....

Bronxboi5

Yes it started as 300/302 then I swaped the 2 to the 4 and now it became 300/304

AcuraLegend

D

Damn, i think i might be onto it with that. I bet.my 4th plug is real dirty too...

If i get the p0300 code to return, and,my cyl misfire jumps...ill look at the injector on cyl 4.

Thanks for the reply!

CS_AR

Congratulations! I think you've got it nailed. If moving the coil doesn't change results when you run a "power balance test" and block out Cyl 4, then I bet it is a fuel issue.

I had random misfires on Cyls 2 and 5 that the dealer couldn't figure out. It turned out to be broken injector pintle caps that were causing uncontrollable flooding, hard to start, misfires, and bunch of other issues.

Child_uv_KoRn

iTrader: (7)

I have ran injectors with those caps broken/missing with no issue. Those are commonly broken with high mileage. I assume they do nothing.

AcuraLegend

It was even easier. I moved the coil to cyl6, and the misfire code went from 4 to 6. Got an OEM quality coil from napa, and well, its running better than it has in months. But still with a rough idle and random misfire.

Im still getting a random misfire. BUT I think it might be fuel like you said.


Cant I unplug the injectors, and monitor the idle? If it doesn't change, look at replacing that injector?

AcuraLegend

I'm down to TB and injectors. I am making great progress. If I had blunts for all of you, we'd all be high right now.

But, I'm still pretty sure my TB is toast. I did the tests on the harness and continutiy on the TB control unit, and they are getting power.

But with the throttle depressed, and the ignition 'on' the valve doesnt move at all. I need a new TB im almost sure.

AcuraLegend

SO I pulled the injectors on the front bank while at idle, and with each cylinder deactived I could see a major misfire.

I'm left with an erractic idle, and an intermitent mis on heavy throttle.

I also notice I'm not getting any advance of the throttle when driving, even if I floor it. I think my valve is shot, and stuck closed-or barely open at best.....

My neightbor has a 2002 max gle.....I wonder if I bake him a pie, if he'd let me borrow his TB for 10minutes?

nestorlugo

iTrader: (11)

This makes the bank1 the main suspect!

No give him a shortbreadcookie and put the scaner on his ride to compare numbers....

AcuraLegend

I'm not sure I follow. Bank1, the rear? The one under the plenum? (cyls 1, 3, 5 ? )

I guess I could try the same test on the rear - but I can also deactive the cylinders via my Android app/OBS scanner. I see a major difference when I deactivate my cylinders now. I'm thinking fuel is less likely after the new coil fixed my cyl 4 misfire altogether....


Any hints on what the air output on a working TB should be?

nestorlugo

iTrader: (11)

Yes run the test on those cyl 1,3,5,.and no I've never touched a 3.5 yet but when i do...

If the results are unsatisfactory then there should be no problem removing the plenum againthis when george_ always preaches! Oem on the rear bank1 ngk platinum and Hitachi coils'

AcuraLegend

It's late, so I think I;m not explaining clearly Sorry.

All of the REAR bank are OEM coils. I also did all NGK plats on all 6 last week. they're new back there.

My misfire is MUCH less violent. It's not a cylinder deactivating mis anymore. That was fixed by replacing the coil that jumped from 4 to 6 when I swapped it.


My misfire is now really only at idle. Also, no CEL at all if I let it idle. I let it run for 30min, no SES. I took it for drive, still rough idle. Give it heavy throttle and SES come on. I checked it immediately - and no cylinder code - just random misfire. I also notice no change in power when I press the throttle. RPMS rise, but I'm not getting any throttle response. That paired with the fact it wont open when I press the pedal - I think the LAST thing to fix is the TB.

So far it was:

-Dirty IAVT solenoids
-Dirty Plugs (all new)
-Non oem coils - replaced 2
-Destroyed intake gasket
-Cracked PCV gas blowbyhose
-Cracked PCV rear intake hose

I hope that makes sense, it's late