TheDuck

Hey there, been around these forums for years... but only made an account here about a year ago.

My car doesn't start, and won't even turn over, but before I describe the symptoms I'm going to begin with a rant as to why searching the forums hasn't worked for me. Yes, so much information can be found by searching, but when people use the wrong terminology it makes my blood boil!

CRANKING, spinning, and TURNING OVER are the same thing... when the engine completes revolution by any means, though usually referring to the starter motor... but has absolutely nothing to do with the next term-

FIRING- is when the engine is turned over and sputters, coughs, spits or the next term-

RUNS- when the engine operates under its own power, whether optimally or not.

Well my search terms always lead me to the wrong information because of some peoples' bastardization of terminology... so now I'm forced to ask for help.

Well here's the backstory/problems:

1. I have a 2005 350Z and have had the NATS antenna problem (rarely) over the past year or so, as typical... fuel pump doesnt run, the engine cranks and the red light on the dash is on solid. Simple solution, pull key and try again. I have never got stuck anywhere because of this.

2. Last February I splashed down in a puddle like an idiot showing off at about 20mph (not deep at all) I parked the car shortly aftewards. about 5 minutes later I went back to the car and noticed the parking lights were on despite them being switched off... started the car ABS and SLIP lights came on the next time I tried to start the car about 10 minutes later. It ran and drove and stopped fine, but as indicated there was no ABS and traction control was out.

All the above problems went away the next, next time I started the car so I figured something got wet, no big deal, it dried out, and don't be so stupid next time. Well this problem reoccured about 3 more times since, and at random times, and not when it was wet.

3. Recently... since it started heating up here in FLORIDA sometimes the car wouldn't turn over at all when turning the key to the START position. I found that if I wiggled the key in the START position the engine would then turn over and start, providing that I didn't coincidentally encountered problem #1 at the same time.


AND here's the BIG issue:


So I went to move my car in the driveway 2 days ago. My driveway is VERY steep, and I'm not sure if I stalled it as I approached the incline (I do this sometimes when I haven't mentally switched between my vehicles) or if the engine sputtered out on its own... but I couldn't get the engine to start. It wouldn't ever turn over again no matter how much I wiggled the key. I put it in reverse and tried to pop it.. no luck, it never fired off at all.

I checked the most obvious first, to no avail:

A. When I turn the key to start, a majority of the dash lights go dark, the radio goes off, etc... as normal, I also hear what sounds like a relay or something clicking in the left side of the dash. (Whats that?)

B. Listened for fuel pump... it primes when key is first turned on, but only once and not again until the car sits for some time and depressurizes.

C. Clutch position switch. This test GOOD with continuity test when button pushed.) I got on the floor and pushed it in with my finger all the way and tried to start, nothing. Also entertained myself by disconnecting it and hardwiring the wires together.... still nada.

D. Relay swap... I swapped the relay for headlamps to the starter and vice versa... the starter relay worked for the lights... car still would not turn over. In fact I tested all the relays by putting them in the headlamp position, and the lights came on always indicating that my relays are fine.

E. Fuses... ALL GOOD!

F. Hard wired the starter relay with a jumper wire I made, then attempted to start the car.... THIS MADE IT CRANK... but it did not fire. This indicates that my keyswitch, the starter, and the solenoid are all good working parts... as is my battery. I put the relay back in its place.

G. Checked for OBD error codes... NONE!

H: Reset ECU just because... STILL NO JOY

I: Also, there are no fans-on-full-of-ECU-death symptoms.

I read somewhere that the ABS control module, if malfunctioning can cause the car not to want to turn over or anything, and since I did have problems with ABS/SLIP lights in the past, maybe this is related. It was suggested to disconnect the ABS computer and try again. (How stupid is that I should have to?) ABS shouldn't leave someone stranded. Thankfully I am at home.

Where is the ABS computer located? I'll try disconnecting that next.

I think I've been pretty thorough in diagnosing this to the best of my knowlege here.

So before I start throwing money at the problem, does anyone else have any other suggestions?

If this were one of my old VWs I'd have had it fixed in 5 minutes, 20 minutes if it needed a new starter. LoL!

Thanks in advance!

TheDuck

Well I pulled up a schematic and found there should be voltage at one of the pins in the the clutch switch when ignition is on. I checked... and got 0v when off, and 0.24V when on.

I don't know about you, but that to me means bad contact, or a stray single filament wire short somewhere.

On the schematics I traced the CLUTCH PEDAL SWITCH back to FUSE #89 in the IPDM, it was a little tarnished on its contacts so cleaned it and the socket and put it back in... now 0.35V at the CLUTCH PEDAL SWITCH. Well, that is an improvement!

Somewhere around this time I accidentally bumped the WIPERS SWITCH while further testing in the car and they didn't come on. I found that to be interesting... I had heard the fuel pump before... but the wipers didn't work at this time either... and the car is still not turning over.

FUSE #89 traces back internally of the IPDM to the IGNITION RELAY.... while the relay tested good in the headlamps socket, this time I pulled it back out and examined the contacts...


ICK! (pins slightly bent over only for photographic reasons)



I cleaned the ignition relay socket, and swapped the highbeams relay into its place.

I turned key, heard fuel pump.... wipers worked... but still didn't start.

But this time it was my fault. The clutch pedal switch wasn't plugged back in. I checked the voltage there... 12V!!!!! Then reconnected it.

Climbed back into seat, stepped on the clutch, turned the key and the car started right up!!!

Now I just have to figure out how moisture is getting into the IPDM box, and clean or maybe replace the ignition relay depending how well it cleans up...

Stuff I learned:

The ignition relay powers a multitude of systems (and other IPDM relays such as the fuel pump) I could have diagnosed this better by checking the wipers and such earlier. Why the fuel pump always seemed to prime was another story... I guess it was because I'm used to waiting a second or two for the NATS sensor to not throw a solid red light on the dash... but when trying to start it there was more amperage drawn which caused the bad connection to be stressed and give out. Easy fix next time, and if the corrosion gets worsened, it'll be time to replace the IPDM box. I'll have to keep an eye on it.

In addition to the ignition relay corrosion which was enough to make a weak/intermittant connection there, that the wiggling of the key was enough to satisify it at times... and that yes the car did stall but not because of bad driving habit.

One more thing comes to mind... here in Pensacola, FL we had massive flooding about 6 weeks ago, something like 50 inches of rain in 48 hours. The Z was parked outside during this storm, and my rain gutter in front of the garage has a tendency to overflow onto the driveway... or in this case since the car was outside... onto the hood of the car. Imagine all that rain for two days AMPLIFIED by the roof of the house dumping all of it onto the car. Thats probably what did it. Might as well of been submerged.