alimooshe

Hello everyone. I'm new here. I was hoping you could help me with the annoying problem I have with my Nissan Maxima 2003.
It's been over a month that my car cranks with one start ONLY when it's been off for 24 hours or more. in the morning it cranks with one start. then after driving for a while, when I turn it off, it cranks ok within 15-20 minutes but if I wait 30 min to 22 hours, I have to start 2-3 times. spark plugs are new- Fuel pump and its filter are new- starter is new- coolant temperature sensor is new- battery is new. I had some technician check the fuel pressure and it was fine(he connected the pressure gauge directly to fuel pump under back seat and tested the pressure at the time when the car was having this issue). there are no error codes with the diag device. camshaft sensor and crank position sensor have also been checked and are ok.
plz help me with this issue.
thanks

Child_uv_KoRn

iTrader: (7)

If cam sensors are original, then there ya go (I would expect the car to shut off while driving if it's this bad, but who knows)

Prophecy99

iTrader: (1)

i agree with Child_uv_KoRns assesment, cam sensors are very finicky and i remember when mine were going bad some weeks would go by with nothing and then every start was an issue, it definitely got progressively worse though after the few weeks of nothing.

and i had a dealer check my sensors and say they were ok and they were definitely not ok, all the problems went away when i replaced them. i had not codes either

carlem9

Could be the engine coolant temp sensor (ECTS) also.

alimooshe

Thank you guys for your attention. I forgot to mention that for almost 45 days at idle or driving the car runs like a champ. No extra noise, no misfire, etc. By checking I meant temporary replacement of sensors and testing if the issue was resolved. All I keep reading is that if cam or crank sensors are faulty, it will definitely show up in idle or driving mode. However I'm no expert and if you both think there are no other reasons for this problem I'll check again with other auto parts.
thanks again.

alimooshe

Like I said I already changed it. No luck

Prophecy99

iTrader: (1)

i dont know if it was said, but the CPS sensors have to be OEM, i replaced mine with napa (aftermarket) and the problems came right back under one year. i had no codes the entire time.

Prophecy99

iTrader: (1)

i dont know what you mean with temporary replacement either, did you borrow the parts and return them? lol just replace them and move on, that way you know that wont be part of the equation again if you get any more problems.

i still vote CPS sensors, based on everything you told us

uptownsamcv

how were the crank and cam sensors actually checked?

try unplugging the MAF when you are having the starting issue again. when my MAF went bad I was able to unplug it and the engine would fire right up but couldn't rev past 3,000 or 4,000 rpm.

may even be a ground issue on the engine block. my last car, which was a Honda, had a bad ground connection on the engine which was an ECU ground. it would sometimes not start for days. after I cleaned the ground I had no issues. I'm not sure if these cars have a similar ECU ground but look for a small grounded wire on the engine coming off the engine wire harness. it may have multips wires on one ground point cause it way also ground the injectors.

alimooshe

Thanks for your reply.
Yeah I asked my mechanic to replace them with the almost new sensors he had in stock (all OEM). and the problem was still there for a full day. I started the car in 20-30 min intervals and it failed every time. Needed 2-3 long cranks. I don't wanna change parts one after the other since parts like new starter, fuel pump and filter, spark plugs, CTS, etc have already cost me a lot!!! (Considering I have a 2003 nissan(lol)) .Yet I don't think any of 'em needed replacement.
Thanks anyway.

alimooshe

I changed the MAP sensor last year. Don't think it's faulty.
Also when I removed its socket the problem was still there.
What I can't figure out is that when the car is absolutely cold it starts at once. So whatever causes this glitch Has something to do with heat. Either one(or more) sensor is malfunctioning when heated or it's the fuel system. My mechanic still insists it's the flywheel that needs to be replaced but I don't buy it.

Prophecy99

iTrader: (1)

how would a mechanic have OEM 20 year old nissan parts in stock dude? you are leaving something out man, and honestly if they were not OEM then it was a waste of time and you can't rule that out. and you said you borrowed parts so did he put the old ones back on?

good luck, if you replaced the 3 cps sensors with OEM, we wouldn't be having this discussion.

Prophecy99

iTrader: (1)

i had hot start issues, it is the dirty throttle body. cold starts fine, hot starts needed another crank or two to keep going, other start issues were because of evap sensor issues after filling gas literally at the pump

alimooshe

He had only one camshaft sensor in stock. I'm in Iran and bro you don't believe what you can find in auto part stores here. The mechanic owns a nissan maxima as well. The other two sensors he took from his own car which were working perfectly there. And yes he replaced my old sensors back.( I also tested them with a multimeter and they all checked out)

alimooshe

My problem ain't Hot start, it's warm start. So when I shut the engine off it starts perfectly within 5-10 minutes. But after that until 20 hours or so the problem exists.

Prophecy99

iTrader: (1)

you can't rule out cam senors untill you replace them with new oem, i am just saying. i get your position and maybe you have a diff problem, but i feel like they way you checked off cam senors off your list was not 100% that's all, i had a nissan dealer check my sensors and they said they were fine too, and they weren't. i replaced them with oem and all my problems went away. but when the sensors were really bad cold starts were an issue to, so you may have something else

have you had the car shut down while driving with no warning? that's a classic cam sensor symptom too just fyi.

good luck with your issue. keep us posted

Child_uv_KoRn

iTrader: (7)

hitachi on rockauto before you overpay (or just go to junkyard and swipe a couple sets of cam/crank)

alimooshe

Thanks for your attention bro.
My car never shut down while driving.( Even in a 400 km trip) That's the confusing part. When it starts there is no flaw at all. Not even a tiny shake. Also acceleration is perfect as if I'm driving a 2016 maxima. I checked the exhaust as well. There's no smoke of any color. However I smell fuel outta the exhaust at all times( not sure if it's relevant). I'm going to post videos of both cold and warm start if that helps.
Regards...

Child_uv_KoRn

iTrader: (7)

Unplug crank sensor and see if it'll start warm within 10 secs.

alimooshe

As far as I know even a small misplacement of crank sensor leads to no start. Why should the car start without it after 10 sec?!

alimooshe

Here's the video for Cold/Hot start :
Here's the video for Warm start:

Veewee

Sorry to ask...2003 maxima is vq35 engine right?

Child_uv_KoRn

iTrader: (7)

B/c ecu doesn't need the crank sensor to run. It only needs cams, but it can't instantly start without crank.
It's just a troubleshooting step. If it does run, then you know crank sensor is bad. Just trying to help narrow it down.

alimooshe

Thank you brother.
I tried what you said. No luck.
Here's the video:

alimooshe

Update:
Following a lead from someone so familiar with Nissan problems, today I checked fuel injectors for leakage/fault. Surprisingly they were all good. No leak/dirt/fault was found. The guy told me leaking injectors might drop fuel to combustion chamber because of fuel pressure. When hot the accumulated fuel needs more cranking. Over night the fuel residue will evaporate therefore morning starts are fine. This seemed to me the most likely scenario to happen. But hell there was no change. 😞

alimooshe

After testing almost everything I finally figured out that the problem was my faulty ECU. Aside from the broken sockets which were almost loose, the signals being processed to fire up the car when it was hot were missing. So I replaced it with a new one. And there you go. 24/7 starts at once. It was a very weird problem, but in case anyone faced it, try ECU.
good luck.

Prophecy99

iTrader: (1)

holy hell! thanks for posting the update ! glad you got it finally figured out, did you notice if it was the somewhat common cause of ECU's failing from the engine mounts leaking fluid and frying the ECU? or did the ECU look ok aesthetically?

Child_uv_KoRn

iTrader: (7)

Interesting. That has to be very rare. Far North or far South?

alimooshe

From what I observed, The ECU unit had been repaired previously and it didn't look good. some connections were replaced by wire and some part of the green circuit was turned into black.
the technician told me it had been manipulated and needed immediate replacement. so that's what I did. It feels awesome to have that pain go away

alimooshe

Far east