PNM35 dead on the road

[Hertz Donut]

PNM35 dead on the road

I've tried searching but I suck at teh forumz so my keywords are probably all wrong. I beg your forgiveness if there's 400 threads I've missed on this topic.

This morning our '04 PNM35 died while my wife was driving the kids to school and would not restart. It turns out it's been hard to start for the past week or so and she's been doing a carby-style start - pump the throttle once it catches but I'm not sure this has been doing anything for it. Today she was driving the kids to school and the revs dropped off to about 1000rpm before coming back up, then a short while afterwards it was game over and she had to coast it out of the traffic.

I can hear the fuel pump priming but when I turn it over only the first cylinder will fire before it shuts down again. I made the fatal mistake of calling out the AA (NZ version of the RACV) and the old guy kindly sprayed brake cleaner all over my air filter (remind me to buy a new one) before removing that and spraying it directly down the intake pipe (I'm sure this is awesome for the MAF) before declaring it was the fuel pump. I remain unconvinced.

I got the car home on a tow truck but I don't have any diagnostic tools to check codes, is there a sequence to get them from the engine check light? Or is this one of those "mate it's definitely the xyz" faults that are common with PNM35s?

Edited August 16, 2017 by Hertz Donut

[Hertz Donut]

And I'll quickly answer my own question here:

Mate it's definitely the MAF sensor. Probably.

I pulled the MAF sensor wire and it struggled to start before firing up cleanly. Plugged it back in again and it'll start first pop but has a check engine light now. Time to buy a new sensor I suppose.

[Duncan]

BTW the AA guy did exactly the right thing.  Dirty intake or AFM was a fair assumption on the side of the road, and brake cleaner is the best thing to clean a dirty AFM with.

Of course cleaning a failed sensor won't fix it, but their job is to fix what they can quickly without tools and diagnostics so it was a fair decision.

It would seem most likely to be either AFM or fuel pump and neither is expensive to swap. So change over whichever you think is more likely and see if it sorts it If you want to spend more money on it you can have the fuel pump tested by a decent mechanic, keeping in mind they tend to fail gradually which means a failing pump will still seem to pump by ear or on a bench but may not make enough pressure when required.

[Hertz Donut]

I thought brake cleaner killed MAFs? Maybe it was some other product, or some other sensor. I should really start keeping track this kind of thing.

I'm 90-ish% sure it's the MAF causing the issue, idle was rock steady once it fired up with it plugged back in, the check light was the only abnormality. I might try driving round the block a few times and see if it happens again. A new sensor is $NZ316 from Nissan (seems a little rich but meh) and I'll throw in a new air filter anyway, this one's over 50,000km old now.

[spudtatoe]

I see you have two PNM35s, have you tried swapping the AFM from the other one to this?

[Hertz Donut]

I have considered it, yes, but I'm kinda worried about ending up with two stuffed cars. I can do that, I can.

[Duncan]

no, brake cleaner is fine. degreaser on the other hand isn't because it would leave a residue on the AFM.

and your car isn't killing the AFM, the AFM is killing the car. so if you do have another AFM just swap it across

[Equilibrise]

The engine trouble shooting codes are the same as v35. Search for that and you will find what you're looking for.

Sounds like your maf is toast. I buy mine from fleabay. Cost $25 or so. It is interchangeable with pulsar, xtrail, wrx, etc. I previously bought an expensive oem maf from Nissan which only last a year or so. The cheap one performs better and will be outlasting the nissan one soon. Worth buying 2 at that price and keep the spare in the boot.

This is what I buy:

MASS AIR FLOW SENSOR FOR Nissan ALMERA PRIMERA 226806N21A 226806N210 226807J500

[KiwiRS4T]

7 hours ago, Equilibrise said:

The engine trouble shooting codes are the same as v35. Search for that and you will find what you're looking for.

Sounds like your maf is toast. I buy mine from fleabay. Cost $25 or so. It is interchangeable with pulsar, xtrail, wrx, etc. I previously bought an expensive oem maf from Nissan which only last a year or so. The cheap one performs better and will be outlasting the nissan one soon. Worth buying 2 at that price and keep the spare in the boot.

This is what I buy:

MASS AIR FLOW SENSOR FOR Nissan ALMERA PRIMERA 226806N21A 226806N210 226807J500

Is that from AU or the US?

[Equilibrise]

Comes from China but is on the au site

[Hertz Donut]

I swapped out the MAF sensor the other day and it started easily enough but it was a little rough on idle. Once it had warmed up though the idle speed dropped to the point it stalled and wouldn't restart so I'm back to square one. Looks like it only restarted after unplugging the MAF because the engine had gone cold.

I've decided it's high time I bought a scanner. Does a regular OBD2 scanner work on these? Like http://www.supercheapauto.co.nz/Product/Bosch-Auto-Scanner-OBD2-Can/411137

Thanks.

[Hertz Donut]

Update: Got hold of a mate's scanner, all it showed was "emissions-related codes" so that suggests all sensors are fine. When I can be bothered I'll start checking relays and power to the fuel pump etc. Sigh.

 

[edit] On the plus side he also dropped off a 370Z exhaust I bought for $50 last year that disappeared for a while. I'm hoping the Y-pipe and maybe the cats fit on the PNM35 without too much coaxing. I'll also do this when I can be bothered. Having 3 cars to choose from and nowhere to work on them has made me pretty slack.

Edited September 11, 2017 by Hertz Donut

[Hertz Donut]

So, being the master mechanic I am, I got round to looking at this and fixed it this morning. I lay awake all night pondering what order to do things in and decided to employ Occam's Razor. Should anyone else experience this issue I have the answer, and fortunately it takes less than 5 minuets to fix.

Solution is...don't believe your wife when she tells you she filled it up. Yup, it was out of petrol. fml.

[Hertz Donut]

Oh, and before anyone asks, no, the fuel gauge doesn't work, because when you run these cars too low on petrol the sender gets mucked up and the gauge stops reading properly. I know this because it's happened to both PNM35s we have. Sigh. Yes, I did miss all the clues, what a champ.