Montego Murph

iTrader: (1)

Hey all,

There are a bunch of posts floating around that can be summarized like this:

Question:
"My I30/Max has a hard time starting... cranks and cranks, sometimes makes a clunking noise... but eventually sputters to life"

Response:
"You should replace your crankshaft position sensor -- the one closest to the oil filter. That one goes out and causes this condition."

For what it's worth, I was participating in this one. There's a youtube link in there to the condition described if you want to say "hey, that's my car too!"
http://forums.maxima.org/5th-generat...ne-sensor.html

HOWEVER...

Don't go buying a new sensor JUST yet. Check this out first.

I removed the sensor (one 10mm and phillips screw for the weather covers, and 2 10mm bolts holding on the sensor. Push the green doodad IN until it clicks, then pull the sensor wire off. Remove the 2 10mm's.

If you'll all open your hymnals to chapter EC, page 521, it says you can use a multimeter to test for resistance between the two contacts. They say it should be 470-570 ohms at 68 degrees F. Also they tell you to check the little nub at the top for chipping.

So I'm sitting at my desk fiddling with my multimeter and testing the contacts, and I get 800 ohms of resistance. Still a little more than expected, but doesn't seem too tragic. If it were adjustable, maybe, but...

Then I start looking at the little nub at the top and it's completely surrounded with road gunk, greasy dirt, maybe some metal shavings, who knows what. The nub appears to be magnetic.

I took some MAF cleaner and blasted the nub, then took a junk cloth and scrubbed it clean, got my fingernails in there and cleaned the groove.

Tested it clean and I came out to an even 1000 ohms of resistance. I have to admit that I'm not sure what it means, but if it wants about 500 ohms at 68 degrees, and it's about 110 degrees everywhere outside right now, maybe there's some variance. Truth is, I have no idea what the ohms have to do with anything at this point. I've never seen an ohm anyway so I wouldn't recognize one if you handed me a bagful of them. Tell you what, ignore this whole paragraph.

After cleaning the sensor, I reinstalled it, cranked the engine, and the starting problem is GONE. It's like a brand new car all over again. No more of this three tries at 5 seconds each while people say "dude, what's up with this car?"

Of course this is only after about 20 minutes of testing and quick errand running. it may very well blow up tomorrow. I'll keep everyone posted if something fails, but no news is good news.

In the meantime, CHECK AND CLEAN the sensor before dropping 80 bones on a new one!

Montego Murph

iTrader: (1)

Update: 2 hours later.

I have not researched the schematics to see what other functions the crankshaft position sensor affects, however I will say that my Denim Dyno has detected a HUGE change in the engine's attitude. When leaving my subdivision I took off onto the highway in the usual way and got pushed back in my seat a little bit -- even chirped the tires momentarily.

Only thing I can figure is that the sensor contributes to the adjustment of engine timing and it was just way off.

Child_uv_KoRn

iTrader: (7)

Useless post on my part, but that was classic.

Good info.

I wouldn't doubt it. I think nissan doesn't tell all about what can affect timing. I seem to notice drops in power due to things that shouldn't be a cause.

edit: And....the ecu does use it to control timing

I wonder if this can be a cause to low power issues in VQs even if they start normally.

Montego Murph

iTrader: (1)

OK... I have some same-night conclusions. Lots going on.

After running some errands (and about 10 flawless starts) I put the car back in the garage for about 2 hours, then got a call and had to step out for a few hours. The hard starting problem is back intermittently, but not as bad as before. I noticed the engine was a little sluggish compared to the earlier denim dyno tests.

Tomorrow (or sometime) I'm going to pull and clean the other two sensors and see what I find.

Amave

don't forget to clean your MAF sensor, i just did it it a few weeks ago and i can notice a big difference in power

Montego Murph

iTrader: (1)

Sunday's Update:

I went ahead and pulled the Cam Sensor and Crank Sensor #2.

Tested the cam sensor (on the right side of the engine, accessible from the top) with the multimeter, resistance checked out ok. Cleaned & Reinstalled.

The other crank sensor -- had a little trouble finding this one because the FSM images were a little vague -- it's on the transmission side of the engine.) This was an oddball because there was no multimeter testing procedure. However it too had little metal shavings stuck to the magnet, so that must have been throwing things off somehow. Cleaned it, replaced it.

Test drove it on a few errands and its back to "quick start like new" condition.

So this tells me that if there was a problem, it was related to one or both of the crank sensors being dirty.

foodmanry

iTrader: (15)

Montego....good finds.

If you saw in your research when I pulled my CPS near the oil filter side of the engine you would have seen the picture I posted of it. The same gunk on the CPS. I had already purchased a new sensor so I threw the new one in anyway.

After doing this my hard starting was gone, but it came back a couple days ago. I'll be pulling the other CPS to clean and reinstall. Sounds like it should do the trick.

Montego Murph

iTrader: (1)

I've noticed that it's about 50-50 right now -- either starts on the first key-flick, or takes an extra second or two, but nothing like it was before.

For right now, I'm going to blame that on the 100 degree heat we've been having -- every car I've owned has started a little hard in this sort of weather for some reason.

foodmanry

iTrader: (15)

I cleaned the other CPS next to the tranny the other day. Started well for that day and the following day. This morning there was the hard start, but not as bad.

This is really perplexing because I put my battery on a charger the other night for a full charge and it was fine yesterday.

I think a possibility might be the fuel filter/screen as I haven't changed mine in over a 100,000 miles. That's next on my list.

Montego Murph

iTrader: (1)

Foodmanry, looks like I we have the same thing going on. Today it's back to the long-start.

I'm going to run outside and throw it on the charger just for the hell of it, but it's cranking so strong, I don't think that's what it is. But I'll try it.

Added the next day: Didn't make any difference.

When you cleaned the CPS on the tranny side, what did you find? I had a bit of metal shavings, I"m guessing from the starter gear against the flywheel for 70k miles.

I do not think it's my filter or sock because when I mash the pedal down (rarely, but it does happen) the engine doesn't sputter and starve like my gf's Miata did when the sock filter was completely clogged.

A good test for the filter would be this -- turn the key on, wait for the humming to stop, then turn it off. Back on again, repeat 3x. I believe the electronic humming nose you're hearing is the fuel pump priming up.

Now that I think about it though, if the filter is SO clogged that it woudn't let enough fuel through to start the car, I can't imagine it would be able to supply enough for extended idling, much less driving.

Montego Murph

iTrader: (1)

Update.

Ordered a new Crank Position Sensor (filter side) from Dave Burnette. Installed it in under 20 minutes (I'm getting good at this). Didn't make a lick of difference.

So I'm a little stumped. What should my next step in diagnosis be? I thought sure it would be the crank sensor because we decided earlier (maybe in another thread) that the crank position sensor determines ignition timing. A few times recently I smelled that "rotten egg" exhaust in the garage after backing in, which is usually a symptom of bad timing adjustment. Also I've noticed what sounds like engine knock/pinging when taking off from a red light.

In the meantime... Does anyone want to buy a crank position sensor with 8 miles on it?

iauditu

My car is having the same issues. Either when the car is cold or after it's been off for a few hours, try starting it in neutral. I tried and in neutral and it starts fine. If it starts in netural with no issues, it could be your neutral safety switch either needs to be replaced or adjusted. It's about $40 online at autozone, but you have to order it. I ordered mine but haven't had time to see if that's it. Another thing I noticed is how I turn the key in the ignition. I have better starts when I put a little more force (not enough to break the key) to make sure I'm turning the ignition all the way, which seems to help as well.

shortymust23

i had the same starting issues got mine done for FREE at the dealership they changed both sensors. call them to see if your vin# is on the list.

T_Behr904

Is this a campaign or recall? If so I didn't receive any notification from Nissan about it. How did you find out?

Will

iTrader: (2)

Hmm, interesting observations.

I had a cam sensor go on me. It's dangerous. The car can stall at anytime like mine did when I was approaching a red light. Thank God I had enough brakes to get her to slow down, before it took 5 cranks to start again. Needless to say, I replaced my cam sensor right away that night.

I agree with the above poster in that you should have your VIN scanned by your local dealer since it was a recall for the VQ35DEs. I'm guessing your Max an '02 or '03? I think most of the '03s had sensors replaced at the port as shipment arrivals from Japan before being delivered to dealers as my '03 was, but it seems like these sensors are susceptible to failure like any other electrical part.

Good luck. Obvious question also is, are you getting an SES or have you scanned the ECU? When my cam sensor went, I threw a code immediately.

Problem is with most 5.5gen owners, many have the SES light on all the time if they've never replaced their charcoal canister and vent valve, and the concern with always driving with a SES light on is that if you have another issue that would otherwise make the SES light come on, you won't know until the car runs weird or you do another scan.

T_Behr904

Mine is a DE-K, and I have the P1320 primary ignition fault code. I've read in a few threads that the crank sensors are the culprit. I hust haven't got around to buying new ones and changing them out. I do have 165K on the car, so I wouldn't be surprised if that was the problem.

OHH NOES

iTrader: (3)

Clean the throttle body.

Montego Murph

iTrader: (1)

Shorty -- I wish I had that option. From what I know that recall was only for the I35, and I have an I30 (2001) so I don't think that applies to me.

iauditu -- I thought about your suggestion and I certainly will try it in neutral, however I don't think that could be it. As far as I understand, the neutral/park safety switch doesn't prevent the engine from starting, per se -- but it opens the circuit and prevents the starter from cranking. The problem we're dealing with is that the starter cranks and cranks but the engine won't start.

shortymust23

call the dealership you might get lucky and check recall sites i'll ckeck the paper with the vin# the mechanic gave me. i'll post the #ers tommorow that qualify for you guys.

Montego Murph

iTrader: (1)

Shorty, did you find those numbers? The local dealership won't tell me anything over the phone, I have to make an appointment and bring it in. Grr.

In the meantime... I changed my spark plugs and that seems to have improved things -- my last three of three starts have been good. Odd thing was that these were platinum plugs with 35,000 miles on them, probably not "worn out" by any means.

DennisMik

iTrader: (2)

There is a technical service bulletin (TSB) that states that Nissan has created a "voluntary recall" for these sensors. It applies to most Nissan models but it applies to the 2002/2003 5.5 gen Maxima. And not all of them. There are serial number ranges. For you guys with an Infinity, the serial numbers are for Maximas. Infinity probably has their own TSB on this.

Read (and download) TSB NTB03-124 dated Dec 19, 2003 from here:

http://maxima.theowensfamily.com/tsb/NTB03-124.pdf

foodmanry

iTrader: (15)

I couldn't get the pull the connector off the sensor on the tranny side. It was really lodged on and I didn't want to destroy it in trying to remove it. Instead I used a can of dielectric cleaner and sprayed the hell out of the sensor.

It helped for a few days. After that, the hard starting issue came back.

Not sure what to do at this point, but I'll take a look at the TSB even though it doesn't apply to the 2K model.

foodmanry

iTrader: (15)

Man...I'm not going replace all of those sensors. If anything I'll try replacing the CPS sensor by the tranny first and see what happens.

My first step today will be to check on the neutral safety switch. If I experience hard start I'll shift to neural and see how that affects it.

Montego Murph

iTrader: (1)

Mine gave me all sorts of grief too. I used WD40, lots of it. Kept spraying it in the socket to rinse out whatever was in there holding it together. Eventually it gave way -- lots of crud in there.

Hmm.

you know, now that I'm writing this out loud, maybe that's part of the problem -- mud or whatever building up, holding water, and shorting something out?

yazz

iTrader: (1)

Montego Murph:

I've been experiencing the same problem with my 2000 Max for the last 5 years. I've had the P1320 Ignition Signal code and have felt this 'clunk' while starting the car. After that I have the ABS, TCS Off, and SLIP light come one. After driving for a few miles they seem to go away. No SES light.

I changed position sensors last year and it did make a slight difference. I also notice that if I crank the key slightly more, the car will start fine and usually get this 'clunk' noise when not cranked all the way.

Recently, I cleaned my air filter in which I had to disconnect it from the MAF. I noticed that after touching and moving the MAF I started to experience this problem once again.

I'm not sure what the culprit for this problem is..

knight_yyz

iTrader: (40)

My CPS has been faulty for about a week now. Pulled the code so I knew what it was for sure. Ordered the CPS and picked it up this morning. The CPS came out of the upper oil pan no problem. Except that the pins on the CPS has rusted into the harness and 2 of the pins were actually broken. So it wasn't the CPS per say, but the pins were broken and barely making contact. So now I need to order the harness and pick that up to get the car to start.

Montego Murph

iTrader: (1)

This is very interesting information, and I suspect it may be the problem with mine as the connector was filled with brown stuff which may have been rust.

You said "order the harness." is this replacement piece a short one that goes from A to B with connectors, or are we talking soldering and splicing into the huge main harness?

CobraKing

^^^
I'd like to know about the harness as well too! The 'plug/connector' for the CPS near the AT tranny pan has completely rusted and seized - I have no way of getting it out!

knight_yyz

iTrader: (40)

The harness has connectors on both ends. part number is 24079-5Y700

Montego Murph

iTrader: (1)

Just got inside. Pulled the 24079-5Y700 and sensor, checked everything over but found no corrosion, missing pins, bulging insulation, or anything suspicious.

I do find it odd that at the top of the harness has 4 wires and the bottom has three wires, it must splice together in there somewhere.

I'm frustrated

knight_yyz

iTrader: (40)

If you look at the connector at the opposite end if the CPS you will notice it only has three wires, but it has an empty spot for an extra wire which is not used. The CPS end has only 3 wires and is not square. They probably use the square end on other cars

knight_yyz

iTrader: (40)

You could try removing the black loom and check to see if any wires are broken.

Also you have a second CPS on the passenger side of the car. How does that one look? It's close to the lower oil pan

Montego Murph

iTrader: (1)

Did that. Nothing. It all looks really nice in there. A bit dusty, but nice. Continuity tests out ok.

I checked all three. (two cranks, one cam.) Everything is OK visually.

The funny thing is, anytime I mess with something, the engine starts great the first or second time. Then it's back to its old tricks. That HAS to mean something but my brain isn't processing it yet.

OHH NOES

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................................................

Montego Murph

iTrader: (1)

I did clean the throttle body. What else do you have in mind?

knight_yyz

iTrader: (40)

Well, you said you checked the CPS at both ends. did you replace them?

Montego Murph

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No, I didn't replace them all. I tested each one using a multimeter and the factory service manual specs, (see posts #1 and #6) and they all tested out healthy. I didn't post this part, but I did pull them a second time and tested them at 70 degrees after sitting overnight in my workshop and the numbers were better.

When I said I "checked it at both ends," I pulled the harness (24079-5Y700) and checked it for continuity and visual damage/corrosion but came up with nothing.

knight_yyz

iTrader: (40)

Did you follow all 12 steps? Each step has about 2-5 things to do according to the FSM.

I Harness or connectors (The crankshaft position sensor (POS) circuit is open or shorted.)
I Crankshaft position sensor (POS)
I Starter motor (Refer to EL section.)
I Starting system circuit (Refer to EL section.)
I Dead (Weak) battery

1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.

1. Disconnect harness connectors F25, F171.
2. Check voltage between harness connector F25 terminal 4 and ground with CONSULT-II or tester.
3. Also check harness for short to ground and short to power.

Check the following.
I Harness connectors F25, F171 I Harness connectors E15, F18
I Harness for open or short between ECM and crankshaft position sensor (POS)
I Harness for open or short between ECM relay and crankshaft position sensor (POS)

1. Check harness continuity between harnessContinuity should exist.
2. Also check harness for short to power.

1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 85 and harness
Refer to Wiring Diagram. Continuity should exist.
3. Also check harness for short to ground and short to power.

1. Disconnect CKPS (POS) harness connector.
2. Check harness continuity between CKPS (POS) terminals and harness connector F171 terminals as follows.
3.Also check harness for short to ground and short to power.

1. Disconnect crankshaft position sensor (POS) harness connector.
2. Loosen the fixing bolt of the sensor.
3. Remove the sensor.
4. Visually check the sensor for chipping.

1. Reconnect disconnected harness connectors.
2. Turn ignition switch “ON”.
3. Check voltage between ECM terminal 85 and ground by briefly touching the sensor core with a flat-bladed screwdrivers.

1. Disconnect harness connectors F25, F171.
2. Check harness continuity between harness
Continuity should exist.
3. Also check harness for short to power.

Check the following.
I Harness connectors F25, F171
I Joint connector-18
I Harness for open or short between harness connector F25 and engine ground


You mention checking something at a certain temperature. I have gone through the FSM and there is no mention of checking anything at a certain temperature.

made in china

iTrader: (7)

I have a full 3.5 swap that has recently been giving me similar problems. I too suspected the crank sensor as that part of the harness was damaged when I acquired the drivetrain from the wrecked donor. But I did a thorough job of fixing it back then.

The symptom for my car is that sometimes when I start it, it cranks way too long. Half the time I will stop trying to start it, other times I'll just let it crank and crank.....If I give up on the first try, let the key go then try again right away it will usually fire up. But it stumbles a bit for a sec or two as it settles into a good idle. If I just hold they key and crank and crank until it starts, it'll eventually start but stumble real bad for 4 or 5 seconds before going "vroom" into a smooth idle. It seems to be flooded, as if the coil packs were asleep.

So, I am in the midst of testing that theory right now. The ECU has a relay control that provides main power to the coils, ECU, injectors, etc. I am considering that on my car, the power my drop out for a moment. So, since my first theory is that my coils may be not be powered while trying to start, I attached a wire to the +V of one coil pack, ran that wire into the car and attached it to an old school test light so I can monitor if the coils are powered while trying to start. Later, I plan on using a scope to see if they are pulsed by the ECU. But for now, I want to just check the +V power from the ECU relay.
Guess what? The darn car starts perfectly EVERY time now! Just like others have experienced, the moment you mess with something, it starts to work fine for a bit. Last week, my car actually did the hard starting crap 90% of the time. It is embarrassing! I've started it about 20 times this weekend after I installed the test light, it's starting on the 2nd or 3rd spin of the starter like any other normal car and settling into a smooth idle right away. Damn these cars are possessed!

Oh yeah, BTW I have a powered test light. It sends a small amount of current through the test point to light a red (+V) or green (GND) LED and sound a special tone on a buzzer. This is a test light that can set off air bags. So I am wondering if the small amount of back feed is remedying a bad contact issue in my ECU relay.....

Anyway, I know you have a 3.0 and mine's a 3.5, but it seems to be somewhat related to the 2000-2003 cars regardless. And my car seems to have it too....

I'll let ya'll know if I find anything out....

1991Maxima1991

iTrader: (3)

i just checked the vin # for the recalled maximas and my vin is specified in the recall, i dont really have any problems as of yet maybe once in a blue moon my car wont start on the first try but on 2nd attempt itll fire up just fine.. Should i go ahead and get the dealership to swap these sensors or just let it ride? sorry if im hijacking :/