Intermittent failure to start...
 

So, i've read all the issues with the steering lock, and this does not appear to be the problem. When i get in my car, push the clutch to the floor, then press the start button, sometimes it cycles straight through and starts as it should. Other times, it just goes to the ACC, then requiring another press to get to the ON. At this point, everything turns on, exactly as normal, except it does not crank. There is no weird noises whatsoever. I can hear the fuel pump kick on, the steering wheel lock disengages, the dash lights and stereo turn on fine, but it doesn't try to start. When i press the button again, it just turns off. The car has always eventually started, but sometimes i have to press the button 40-50 times, just continuously cycling through until it catches.

Does anyone have any experience with this?

Um... Is your foot on the brake too???

It is this your problem:
http://www.the370z.com/engine-drivet...-starting.html

Weird. Subbed to see what the problem turns out to be. Good luck.

BTW, the fact that it will go to ACC indicates to me that the SLU is not the problem. When the SLU fails, you are stuck in OFF and it won't go to ACC or ON.

I would check the clutch switch. It might be out of adjustment or faulty.

I've tried with my foot on the brake, taking it in and out of gear, rolling it back and forth, hitting it, sweet talking it, and pressing the button at all different speeds. I've found no rhyme or reason as to when it starts and when it doesn't.

The engine fires immediately every time it cranks, it just won't crank. Like my starter solenoid never engages. I have no mods on the car and it's got 36k miles. I'm almost completely out of ideas. It's also a degenerative problem as it's gotten much worse.

Does anyone know if the clutch switch is just a contact or if it sends a control language? That's the only thing I can think of now, because I tried disconnecting it and bypassing the switch to no avail.

Thanks for the help.

Sounds like the clutch switch if your out of warranty might be the cheapest thing to try .

Just found the part for $16.68. Ordering it now. At that price, i might as well try it. I just can't believe how intermittent it is. Maybe it's corroded, so it's got a reduced amperage coming back that's only occasionally breaking threshold. I don't know if it's just a 4-20mA signal or a voltage thing, or what.

just so you know if you havent already done it u definately should remove your steering lock fuse

I know of no cars that use 4-20mA. At $16.68, you can pretty well bet that it's not "or what". For that price, it's almost certainly a simple switch.
And, according to the 2009 FSM (EC-536), it's a single-pole switch.

It may be that the switch just needs adjustment or the bracket (if any) is loose.

sounds like the clutch pedal sensor....

i had the one for the cruise control replaced already wouldnt be surprised at all if the regular one went bad as many times as the clutch gets pushed down

Just pulled the pedal sensor switch. It's just a disconnect. No control language, so it's not the problem. Stalled in traffic today. I need this fixed.

Also pulled the fuse and no change. I'm running out of ideas.

If a bad clutch interlock switch is the problem, you can temporarily disconnect the connector on the switch and jury-rig your own switch until the replacement comes in. Flip your temporary switch to the proper position, start car, flip switch back to "normal" position until next start.

If you know what a 4-20mA loop is, you should be able to handle it.

Use at your own risk, not responsible for accidents or damage, &c, &c, &c.

OK, after pulling the clutch sensor switch, taking it apart, and putting it back together, the issue seems to be resolved. However, after looking at the internals, I don't know how the computer knew it was installed. There's no circuit components, just a simple disconnect. Hopefully this is actually the problem and not just the issue deciding to go away for a bit.

Good idea, but it appears to have cleared up after taking apart the clutch switch and putting it back together. I have purposefully changed nothing though, so unless some piece of plastic or something was holding the connection closed, I have no idea how it's become fixed.

Glad to hear it's working again. Keep the spare handy. It sounds like you fixed the problem (not just an intermittent that went away for a while), but the switch is likely to fail again soon.

According to the 2009 FSM, the interlock switch is a simple SPST switch - the module is looking for volts present or not. Some controls in the car are "smart", eg, window switches and SLU, but not the clutch interlock switch. Edit: Ie, the module doesn't know the switch is there until it closes.

Then shouldn't that mean that I could disconnect the switch entirely? When I press the button, it breaks the circuit, so shouldn't it just think the clutch is pressed if I disconnect the switch? I also tried a wire bridge and it didn't work.

I think that the ECU needs to "see" the switch open and close when necessary. If the switch is bridged like you say to keep it closed permanently, then the ECU does not see the change in state. I know when I try to start my car, the dash icon lights up that says to depress the clutch (switch closed) and then the car starts. If the ECU does not see the switch close, then the car will not start. It is a programmed sequence that has to happen otherwise, nada.

Since the bridge didn't work, it would seem that mults is right and the car has to see a transition. I suspected as much (it's not uncommon for interlock circuits), which is why I suggested using a switch.

So, that means if I hold down my clutch, then start the car, then turn it off and try to start it again without releasing the clutch, shouldn't it not work?

Try it and see. I'm just going by the wiring diagrams and a lot of things disappear into the ECM/BCM/&c where only Nissan knows what happens. It appears that the car is looking for a transition, but it may be less (or more) complicated than that.

Strange, well, it hasn't done anything like it, so that must have been the issue. I'll just have to last until the new part shows up. Thanks for the help and interest.

sub'd.... I have the same issue....

the same switch is also used to trigger SRM.

did any of you guys experience any sloppy shifts/SRM not doing its thing as expected when your clutch switch prevented the car from starting intermittently?

and for those who experimented with temporary fixes, did you encounter any irregular SRM behaviour?

wow, forgot about this thread...

see here for solution:
http://www.the370z.com/exterior-inte...ring-lock.html

Never had any issue with SRM.... :ugh2:

my SRM issue turned out to be the Input Speed Sensor on the gearbox. It had some blobs of fine metal particles stuck to it (it's a magnetic flux type device).

Cleaned it up and shifting has never felt so good :)

cheers for the reply though

Hall effect sensors are notorious for failing after magnetic debris gathers on or near them....

Good find! Now swap out your tranny fluids to synthetic....