BigLou55

iTrader: (6)

Haven't been up here in some time besides searching old threads with good information.

DID I SEARCH:
Searching the org is what led me down this path to have to create a thread because most threads pointed at coils or MAF. I think this may be a different case.

SPECS:
2000 Maxima SE
80K on engine
210K on everything else
All grey dot coils
NGK Laser Platinum plugs with less than 3500 miles (more on this later)

MODS:
AEM drop in filter (stock air box)
Home depot/lowes oil catch can (installed after I thought I fixed this issue)

STORY/PROBLEM: Sorry it is long but I need to give details/vent a little.
A few weeks ago while on the highway (approx. 75-80 mph) on a 150 mile trip my car felt like it had a brief misfire/hesitation, almost like it missed a beat. I turned off cruise control, continued on and it did it again briefly. Both times were not bucking or anything but I noticed it happen. The problem did not happen again for the remainder of that trip. A few days later I was returning home from the 150 mile trip and not a peep out of the engine, ran like a dream.

A week goes by, and still no issues at all so I call it done and do not bother with it. I make another 150 mile trip it does the same “miss a beat” deal again. Now this time on the way back from the trip it is hesitating a lot worse, like a stutter then I press the accelerator and little hard (not full throttle) it stops stuttering and goes on. It does this for the 2nd half of the way back and maybe ten miles from the house the SES blinks 2 times goes off then again 2 times and goes off and doesn’t come back. I get home and check for codes and get a PENDING P0303. I think great it’s a coil/spark plug issue. Let her cool down I check the #3 plug and its looks fine based on Haynes manual and FSM so I swap the coil with a spare and think it is fixed.

Then last week my car shows its rear end! I am heading to work (avg. speed 55 mph) and now it is missing like crazy every couple miles. I mean if I come to a stop then accelerate it would sound like a diesel until I accelerated a little harder and it would stop doing it. So I get home from work and start checking fuel injector resistance with a DMM and injectors 1 & 3 are a lot higher than the rest. I have a few extra injectors laying around so I check their resistance and it is within spec based on the FSM. I replace all 3 bank 1 (firewall side) injectors with those used ones that checked out good. I finish the job start her up she sounds like crap but that is expected for a couple minutes from what I understand. She idles down nicely and purrs, so I am celebrating in my head because I am tired as crap. I take her for a spin and all is well. I get back home clean up my tools and start her up again to make sure and she misses AGAIN!

So what I did not do the first time was check ALL the plugs the first time, just #3. Look at them all and #1 is “wet” so I am thinking the previous injector must have been leaking so I replace only that plug because it will help isolate the issue. I replace that one plug and it ran fine for 200 miles and it started missing again today.

I don’t think this is MAF related because it stopped after the sparkplug replacement. Maybe that just masked the issue, IDK.

SOLUTION:
I am thinking either the injectors I used were actually not good or something else is going on. I plan to pull that #1 plug today after work. If it is “wet” again I think it’s a leaking fuel injector. If you guys do not have other ideas of where I should be looking, I may have to let Nissan figure this out. The fact that I replaced one plug and it ran fine for a little while points to that injector I think. I want to get a definitive “this is your issue” before I pull off the IM again lol.

Thanks for reading this and if you can offer ideas/advice that will help me I would be grateful!

UPDATE: Checked spark plug #1 today and it appears fine, not "wet". I cleaned the MAF just because it has been a while since I had. It did not help this intermittent issue but its good practice.

colt149

iTrader: (1)

First of all I will not recommend home depot catch can graded for pressure, most of the time the bottom part have a vacuum leak. I even used the jeg catch can and noticed the tip of the tubing of intake manifold have oil, this small catch can is not enough to hold the high vacuum of VQ35DE and VQ30DE engine. I upgraded to ADD W1
http://www.ebay.com/itm/ADD-W1-Black...35b02a&vxp=mtr

Never use a 3/8 fuel and transmission tubing to oil catch can. (collapses in high rpm)
Must use a 3/8 graded PCV tubing.
Clean the MAF sensor.
Reset the ecu
Replace transmission fluid with Amsoil Synthetic ATF.
If the spark plug is coated with oil, replace spark plug tube seal and valve cover gasket.
Good Luck

BigLou55

iTrader: (6)

I cannot say I agree with you on the fuel hose comment. The fuel hose I used is reinforced. The PCV hose I have seen is not. So i do not think I have an issue as far as the hose I am using goes. I mention in my OP that the catch can mod was done after I thought I fixed the issue. However I did return to stock setup today just to make sure and it still did the intermittent "miss a beat".

As far as the MAF cleaning, I did this today as well because I knew I hadn't in a while even though I knew it was not my issue. It did the miss/hesitation again after cleaning it.

I run Nissan Matic D in my tranny and have been since I have owned it. The fluid level is good, red, and stinks like tranny fluid should (not burnt). So again I do not think this is the cause.

My plugs are not coated with oil so I can rule that out as well. I mentioned in my OP one was "wet" and since replacing the bank 1 injectors it is no longer the case so I believe I am ok there.

Again thank you for your advice and help me think through/rule out more possible causes. I hope I am not over thinking this issue. I think I have looked at many of the common/simple items.

95Maxi

iTrader: (40)

Have you checked the actual harnesses? Wires? Grounds?
Compression test ? Clogged Cats? 02 sensors? They all may seem not related but I have been surprised in the past and smacked with reality that certain things we focus on the most during these issues are not always the cause.

Just my personal experience with maxima's on #29. From 95 to 03.

BigLou55

iTrader: (6)

I have no CEL for this issue, it blinked 4 times as I stated earlier read the code and it cleared itself the next day. In my experience emission codes have always gave me an CEL and bad MPG. I get 23 city and 26 highway currently. Just filled up again today and it was 23.6 mpg.

Took it to Nissan this morning and they could not pin point the cause but did notice the misfire/skip while it was on consult. Tech said it was too quick and small for it to identify are particular component. They mentioned a TSB related to the wiring harness having breakage could be the cause. When I left I pulled over and violently shook the harness, particularly at the bends near the passenger strut...nothing happened. I am not sure how to tackle confirming a harness issue.

The service tech did advise me to change all my coils at once and see if it goes again and move to plugs next if that doesn't correct it. I have an extra set coils so I swapped all 6 out and since then (maybe 60 miles) it has not missed/skipped but I won't call it fixed until it has been a bit longer. I will not be upset if that was my issue though.

I will update when I know more. again thanks.

BigLou55

iTrader: (6)

UPDATE: PROBLEM FOUND: 95Maxi, you were correct with the harness being the problem. I kept messing around under the hood the other day and decided to focus on the section of harness that connects to the #3 coil. I let the car run and begin moving around that section of the harness and it started missing. So I kept at it and pressed the wire slightly against the connector and it would consistently miss until the p1320 and p0303 were pending codes again like before. I cleared the code and did it again and it came back instantly. Thankfully I have a spare engine harness, that I could use a donor pigtail from. I spliced it about a foot back to be safe and get a much of the damaged wire as possible. Cleaned up my wiring and now she is running well and no missing.

Now I can get on with my suspension replacement!

maxinout93

glad you found the problem because i have the same issue of P0303 and rough idle/missing at times it runs good and other times it runs like crap.

jackman

You realize this thread is 2+ years old?

maxinout93

Yes I did but it is good to search before posting a new thread. It is helpful information directly related to a similar issue I am having.