reallywildstuff

Today the CEL came on w/ new codes I hadn't seen previously: P0154 & P0134, "both O2 sensors report no activity". CEL light not on recently.

Both O2s still plugged in, and I haven't been working in engine room recently. If it was maybe just one or the other I'd more strongly suspect a bad O2 sensor - however both tripping for the first time, at the same time, makes me think they're more symptomatic of what else is going on:

Still seeing a 25 rpm dip in idle in neutral/50 rpm in drive that's been present since upper end was cleaned.

ALSO now seeing delayed acceleration/hesitation for last several days, like what's here:

https://maxima.org/forums/4th-genera...rive-auto.html

There was an EVAP code a while back but it hasn't returned - I haven't checked the purge valve yet.

There are no vacuum leaks - I just now sprayed the S out of the vacuum gallery and everywhere else with carb cleaner - no rise in idle observed.

I am thinking that the dip in idle and the delayed acceleration are due to "bad coil" or "coils" - even though I'm not getting codes about missing cylinders (yet).

We have: recent new air filter, new Bosch MAF, cleaned TB, IACV, and EGR guide tube, new fuel filter, new PCV, new NGK plugs (one hole with oil), new OEM knock sensor, new OEM absolute pressure sensor.

Do YOU think these O2 codes, given the other symptoms, are indicative of anything other than "bad coil(s)"?

Do YOU think the hesitation/bucking is due to anything other than "bad coil(s)"? If its _not_ coils then "injectors" is all I've got left...

I'm not scared to buy 6 new OEM Hitachi coils from RockAuto if its reasonable to expect replacing them to solve these issue(s).

Thanks and appreciate any help -

BrianA in Houston

The Wizard

iTrader: (43)

Do the unplug a coilpack one at a time trick and listen for a change in RPM. If no change, then you've narrowed down the cylinder and coilpack/injector.

Swap coilpack with another cylinder. Repeat test and see if the no change in RPM moves with the coilpack. If so, that's your coilpack to replace. If not, then it could be the injector failing on the original cylinder.

Start there. Free and easy diagnostics.

What year is your Max? You should add it to your profile so it appears on the left by your username.

PH98I30

I have the same car you have. I don't have much faith in your Bosch MAF sensor. Maybe your fuel pressure regulator is going, but The Wizard knows more than I do.

JvG

I might be able to help.

I replaced both oxy sensors within the last 10,000 miles or so. Replaced with NGK, if I recall. I used the kind which have a raw end..... no plug. So you splice the old plug on to it.

All was fine... till recently. The codes was for the sensor facing the radiatior, the usual knock senor code, and the same code for the oxy sensor again. I re-spliced the oxy sensor, taped it well.
Clearn the codes. Start car. Instant check engine light, same codes again......hmm

I did a search on the forum....... blown fuse does that.

So I checked the fuse.... which was NOT blown.

I noticed that it's contacts looked oxidized. Which creates resistance...... setting a cel .

So I used fine sandpaper to clean the fuse. I shoved it back in, cleared the codes, and no more check engine light.

So sand the fuse. Cheap and easy.

reallywildstuff

Thanks Wizard, PH98I30, and JvG. I reset the codes same day (two nights ago). Report from yesterday, out all day running errands, is that it drives really well in AM and hesitates badly in afternoon. No CEL.

I will look at the O2 fuses. I will inspect the coils - but as TIME is always against me, I'm still planning to replace all six at once.

Re Bosch MAF - I don't know what to say. This is "the best" non-OEM MAF available, the box said "Made In Japan", and the part looks and feels just like the OEM piece...only thing it lacks is the pink JECS sticker. I acknowledge that a bad MAF will F everything else up but can't justify the expense of the OEM MAF at this time.

Also forgot to add that we are running Premium gas until further notice re: isolating this problem. I know it's supposed to have premium fed to it all the time - but the reality is it's had Regular it's whole life.

JvG

Hmm .... temperature related issue perhaps.

The engine temperature sensor reads coolant temperature.

I had some oxidation on that sensor on another car. I sprayed brake cleaner, or electrical contact cleaner, and sanded wthe 600 grit sandpaper. This removed the oxidation.

Some sensors measure electrical resistance and report that value to the computer. If oxidation is present on a sensor, the wrong resistance is reported to the computer. Basicly lying to the computer.

So sand the contacts or relate the sensor. I'd do the sanding. Might be a free fix

reallywildstuff

I unplugged each coil in turn - they were all firing.

I replaced all six coil packs with Hitachi-branded units from Rock Auto - "Hecho in Japon". The old units were labeled Hanshin.

The dip in idle/missing at temperature seems to be gone now, and the car seems to be running _really_good_ at the moment (watch - now the CEL will come on today for some BS reason). No repeat of that one EVAP code or the O2 codes. No AIR BAG light, No CEL.

JvG

Congratulations!

You have done a lot of deferred maintenence.

Now your car runs as Nissan intended it to.

reallywildstuff

My wife continues to report that this car is running its a** off all the time w no indicator lights and no drive ability issues. "It makes me want to pass people 'cause it's running so well"

I do, however have to add 1/4 Quart of oil every-other day to keep the oil level on the "H" mark of the cross-hatch area of the dipstick. I don't know why this leaks "so much", or whether this is typical for a 19 year old example that's never had its Upper Oil Pan pulled - but the smell of burning oil in my garage is getting old, as is the mess, hassle, rotting suspension etc. I ack first world problems.

The Wizard

iTrader: (43)

at adding 1/4 of a quart every other day. We know what you're fixing next.

reallywildstuff

It's been only a month since I replaced all six coils and reported excellent drivability.

For the last week there have been general complaints re a return of intermittent surging/bucking (as described previously) as well as transient CEL lights. I was able to observe a P0300 (General misfire) which I cleared three days ago - it has not returned. Despite earlier guarantees Regular gas had been introduced - but we have re-committed to Premium.

Today the report was more weird drivability issues ("loss of confidence" was mentioned) as well as a return of the original P0154 & P0134 codes. I cleared the codes and went on an uneventful test drive - however after a stop and start, the same two codes returned. I've cleared them again.

Previous posts in this thread describe recent work to date. I have yet to replace the fuel pressure regulator or service the injectors. I have never serviced the O2 sensors. I appreciate any guidance re returning to "excellent drivability".

Thanks

reallywildstuff

These two codes keep coming back. I guess Ill replace two O2 sensors and re-examine.

Whats the highest quality O2 sensor available?

Thanks

LJay

I just replaced mine recently. I used Bosch. I heard Bosch & NTK are just about the best

flynlr

iTrader: (2)

something weird. when I bought the bosch sensors brand new NTKs were what was in the box.
this was both banks and the one on the cat "95 Cal Emissions"
.
here is a scan of the one on for the CAT marked NTK
same exact part as what was removed from the factory
so OEM part at Rock auto closeout price when I bought em
.

reallywildstuff

I've purchased two NTK #24525 and one NTK #24630 from Rock Auto - $147.36 and they'll be here Friday. NTKx3 was a few dollars less expensive than Bosch. I went NTK because its the OEM part.

The car didn't run so poorly yesterday (even though the CEL came on with the same O2 codes). I am hopeful that properly functioning O2 sensors will cause the computer to un-F itself - or at least give me some other codes to go on re: poor driveability.

JvG

I asked before, did you clean or replace the oxygen sensor fuse?

It powers your sensors. Oxidation of the fuse can make both oxy sesors set a code.

LJay

Yes! Check that fuse! That was my problem. I replaced all the 02 sensors & the codes weren't going away. Then I replaced that fuse & it's been gone ever since

reallywildstuff

Thank You JvG re: your tenacious pursuit of slackers.

This evening I did examine and re-condition the 15A O2 fuse - there was a not-insignificant amount of brown/black corrosion on each side of each blade. I fine-sanded the fuse to "shiny", reinstalled, and cleared the recurring code (again).

I shall advise further as the situation warrants. Thanks again.

JvG

I might be a pain in the rear, but if I have experienced an odd problem first hand, then fund a cure, I will share it.

The cell codes might say oxy sensor, but we need to keep in mind that the whole circuit could be suspect. Oxidation and corrosion can cause un needed parts replacement.

Our cars are old now, and have old- age issues.

reallywildstuff

day 1 after sanding O2 sensor fuse contacts: no codes, no drivability issues

JvG

Glad this worked for you, just as it did for me.

reallywildstuff

Ah, but Day 2: no CELs, but "poor drivability" again, and more pronounced. Ill say that the "no voltage to O2 sensors CEL" has been fixed by sanding the fuse contacts - but serious intermittent drivability problems remain.

My pilot is getting..."anxious" re not beig able to accelerate from idle, then blasting off to the moon at 3000 rpm. She also reported a "knocking" during one hesitation episode - maybe just a misfire. Again, no warning lights, no CEL light.

Im going to spray the MAF with MAF cleaner. Dont know what else to do besides...FPR? But wouldnt it throw Lean codes if not enough gas was being introduced?

Any reason to NOT suspect 20 year old 112k mile O2 sensors maybe not reporting all they should? But that kind of sounds like backsliding into the solution to me...

I am open to suggestions.

JvG

If your oxy sensors have never been replaced, by all means, replace them.

I assume that your spark plugs have been replaced, and that you cleaned your throttle body and have sprayed maf cleaner on your maf. Also that all contacts are reasonably shiny?

reallywildstuff

YES. All work to date is in this post.

reallywildstuff

I cleaned (for the first time) the almost-new MAF and replaced all three O2 sensors.

The two pre-cat O2s had a lot of carbon buildup inside their sensors. Also - even though I'm pretty sure these had never been replaced, they were all three Bosch (w Nissan logo stamped on housing). I had thought NTK was OEM...?

Test drive was unremarkable - seems to drive really good today. We shall see.

reallywildstuff

Today's bad news:

On the highway, 3000 rpm and 50mph, increase throttle to accelerate and RPMs drop precipitously to 1000 RPM, then back to 3000 RPM, back and forth like that several times until it kind of smoothes out...struggle thru the rest of the highway portion of the trip, exit highway and stop at red light, engine dies. No CEL.

As I have replaced or serviced seemingly every other recommended component - I'm thinking "Fuel Pressure Regulator". But I appreciate any guidance.

reallywildstuff

I am shooting in the dark on this extremely intermittent driveability deal but COMBUSTION = AIR + FUEL + SPARK, right?

I've cleaned/serviced all the AIR portions (MAF/TB/IACV/EGR Guide Tube).
I've service all the SPARK portions (6 new plugs, 6 new coils).

What's left is the Fuel Tank, Fuel Pump, Fuel Filter (replaced), FPR, fuel rails, and injectors. My research shows a failing FPR typically manifests as a hard start condition - not as "not enough gas on the highway/at idle" (like I'm seeing)

Similarly, it seems that when injectors fail they fail in the open position (pintle caps) and deliver too much fuel, flooding the cats (not too little fuel).

Appreciate any advice re: why this car won't run right all the time.

reallywildstuff

Todays report was "no issues".

There is a full tank of gas (premium) in it now. I will track these issues against how full the tank is - I havent been, but wonder if there are more problems when the tank is less than half full.

This car has too few miles (112k) to not be a team player at this point. I need to iron out these issues to justify an R&R of the motor re: oil leaks.

Thanks

The Wizard

iTrader: (43)

While this is true, a failing FPR will also cause driveability issues. I've had a bad FPR cause driveability issues when I gave it moderate gas...car surged, fell on it's face, then back to normal. Gave it moderate gas again, and it stalled. Wouldn't start again, even after waiting 30 minutes on the side of the road. Was towed home. Started up fine the the next day like nothing ever happened. I didn't even bother going for a drive. I replaced the FPR and never had a problem since.

But before you go on a witchhunt for the FPR, monitor the Max now that you have a full tank of gas. If the problem arises only when you have a 1/4 tank or lower, then you either have a weak pump or fuel pump sock pickup issues. This is not to say you couldn't have a failing pump at a full tank of gas and not have symptoms.

Have your wife keep a close eye on the CEL. If it ever flashes rapidly and goes away, that's a tell tale sign you have a bad injector, which would cause these driveability issues as well.

jholley

iTrader: (13)

+1

When my pump started failing I was getting random misfires (P0300) only after driving for 15min or longer. After stalling during 20min of city driving it started again after letting it sit for 40min.

Have you tested the fuel pressure yet? My weak pump only gave 20psi while idling then stalling after squeezing the fuel return hose. I replaced the fairly new fuel filter but that made no difference. That narrowed it to a weak pump or fuel sock clogging the feeding hoses. The FPR was fine.

EDIT: I replaced the OEM fuel pump with an Hitachi pump I got from rockauto for ~$90. That solved the hesitating, misfiring, and stalling issues.

reallywildstuff

like this @ $82? Did it come with the short length of hose/two hose clamps as pictured with the Bosch item?

http://www.rockauto.com/en/moreinfo....305098&jsn=515

compared to the OEM @ $248:

http://www.orderinfinitiparts.com/pa...&siteid=215003

That's a..."hugely compelling price disparity". I knew writing "all OEM all the time" earlier was going to make a liar out of me...

jholley

iTrader: (13)

Yup I installed that Hitachi FUP0015 Fuel pump and it works great. While idling it reaches 38psi so she accelerates faster now.

Check the fuel pressure first before replacing the pump. It an easy task similar to replacing the fuel filter. You can rent a fuel pressure tester at an auto store if you don't have one.

It comes only with what you see in the picture --> The sock (fuel strainer) and harness that connects to the sending unit. The fuel hose was in good shape so I didn't replace it. I just replaced those cheap spring fuel hose clamps with SS fuel hose screw clamps. You also have to replace the tank seal O-ring. Another object you have to order to get the pump warrantied is another fuel strainer F295S. Rockauto claims the pump doesn't come with a strainer but that's an error.

Use this discount code to get 5% off 4608209941562959

reallywildstuff

Today was: No problems on the way to work early AM; Stalled four times leaving work parking garage in PM. CEL came on during one stall event, but did not stay on.

My next move is to test fuel pressure. I have only a carb pressure / vacuum gauge so I'll either be borrowing or buying the fuel injection tool.

Got a favorite fuel pressure tester?

jholley

iTrader: (13)

Our fuel lines don't have a schrader valve so all you need is a test set that includes an analog pressure gauge and a t-fitting. All auto stores stock them for sale or rental. If you're purchasing a set then also include one foot of 5/16" fuel injector hose and clamps for that hose.

reallywildstuff

I borrowed one from O'Reilly and installed it in-between the filter and the engine.

Idle = 28 psi (spec is 34). Needle bounces unless throttle is applied.
Turn Ignition From Off to On : 20 psi (spec is 43)

My hand-crank vacuum pump was KIA and I hadn't replaced it - so I couldn't test the FPR.

I think I need a new fuel pump and pickup. Thoughts?

jholley

iTrader: (13)

You no doubt have lack of fuel but having the fuel PSI bounce questions me? When my fuel pump was failing it held steady at 20PSI while idling.

While idling try disconnecting the FPR vacuum hose. If you cannot reach the hose on the FPR then disconnect it on the UIM. That hose is located on the right side of the TB in back of it. If the car stalls when disconnecting that vacuum hose then's it's a weak fuel pump or a clogged feeding hose. Not a bad FPR.

reallywildstuff

I bought a Beck Arnley fuel pump w/ strainer from RA. It says "Hecho in Japon" on the box and the xeroxed directions say "Hitachi".

The old fuel pump had the embossed Nissan OEM logo on it (original).

I bought a new FP gauge - the previous fluttering needle was due to "loaner tool" only.

Old pump: 28 psi idle / 18 "on"
New pump: 36 idle / 44 "on" **Winner!**

I also bought a new mighty vac - after replacing the fuel pump, I tested the FPR:

Idle, Capped vacuum line, 0 inches vacuum at FPR: 46 psi
15 inches at FPR: 40 psi
25 inches at FPR: 35 psi

I think these figures = FPR operating within specification. Comments?

I believe I have now serviced everything on the induction side that's serviceable, save injectors, culminating w this fuel pump. I suspect that many of the previous parts replacements, while each bringing improvements on their own, could have been postponed in favor of testing/replacing the fuel pump much earlier. The car/pump only has 112k on it - I believe "20 years old" is the most relevant figure vis-a-vis this failing pump.

Car starts and runs hella better now - poor baby wasn't getting enough gas.

Thanks to all who helped out w good advice...

reallywildstuff

This car has been running REALLY well with NO drivability problems.

It needs Inspection, and after the recent alternator/battery adventure It wouldn't pass re: Not Ready "4 INC". I reset the trip odo so I'd know when 100 miles had passed...then the computer would probably report OK, and I'd retry inspection.

My pilot reports that at 97.5 miles, the car stuttered (in a familiar yet surprising way, as it'd been quite some time since that happened) and then the CEL came on. At their destination they checked the codes (On but not Running) and got PO154 and P0134 (both O2 sensors report no activity) and P1493 (EVAP canister purge control valve). Also, "3 INC" (catalyst, EVAP, and EGR). They did not start the car again and they did not clear the codes.

When I checked it just now hours later, there are _no_ MF codes and "4 INC" (the same 3 as before plus O2). 104 miles on the trip odo. I checked it before starting it and after.

I suspect (but don't know) that it is READY for Texas inspection even when some systems report INC...but I'm unsure about that and don't know which systems are OK to report INC (if any). Thoughts?

Why did the CEL light turn off (and codes clear) even though it didn't get started again?

What's up with my sanded fuse, brand new NTK O2 sensors throwing codes?

And how about that EVAP code also clearing with no outside stimuli? Is that S Wild or what?

Thanks for any advice. Seriously this S is getting kind of old. $800 in 45 days on tires, alternator, and battery and still can't pass Inspection.

BrianA in Houston

reallywildstuff

I could really use some help determining a path forward. I need to pass Texas Inspection.

This car is still running very strong with no driveability issues however the SES light continues to appear (and disappear) at random times. The codes are being gathered with a handheld scanner but NOT Erased - instead the codes seem to be clearing themselves. How is that possible?

The most recently observed codes were P0151 & P0131, "O2 Sensor Circuit Low Bank 2 Sensor 1" and "O2 Sensor Circuit Low Bank 1 Sensor 1".

These are new NTK O2 sensors. I had previously sanded the O2 sensor fuse blades free of corrosion.

These two codes are described together in the FSM page EC-157:

http://boredmder.com/FSMs/Infiniti/I30/1998/EC.pdf

Prior to these codes it was showing P0154 & P0134 (no O2 activity, both banks) and an EVAP code (P1493). These codes have not repeated and also seemed to be "self clearing" (the SES light de-illuminated without the ERASE button being pressed on the code reader).

What's up with the codes clearing themselves?

What can I do to address the conditions the codes indicate? I have not yet touched the EVAP purge valve (code hasn't repeated) but will soon. Most of these problems are re: O2 sensors - but they're so intermittent, and I don't know what to do about them.

Appreciate any help.

reallywildstuff

Please help me find parts listings for the replaceable EVAP hardware located at the rear of the car (near the EVAP canister), including the "EVAP control system pressure sensor" and "vacuum cut valve".

These part names are on page EC-27 of the 98 i30 FSM.

I couldn't find these under Emissions or Fuel at the usual places.

Thanks.