Reece350z

I have a Nissan 350z fair lady 2003 with 80k and it's an auto.. So after fitting a new conrod because I drove through deep water. I built her back up and the car started briefly for 3-4 seconds then cut out and wouldn't start again so checked for a spark by taking the plug out and putting it on the body and there was non but there was voltage to all coils so I checked resistance through the coils all ok Checked all fuses all ok. Checked fuel pump and plugs were soaked in fuel when I took them out so fuel isn't the problem. Tested crank and cam sensors all ok. Didn't remove flywheel so it has to be on the right mark, done a compressions test and all cylinders were 50psi which is really low? So it made me think I'd timed it up wrong so checked timing again before and took the chains off and done it again and it all lined up as fsm but still won't start.. Has no fault codes. Please help! Any ideas would be appreciated I'm totally stuck. Could all 6 plugs be broke after going through water?

PP08HR

iTrader: (2)

You said you didn't remove flywheel but you did remove complete engine out of vehicle right?


I'd bet you got a pinched fuel line. Check fuel pressure at the rail if low start looking backwards.


I also assumed there is spark at the coils right?

Reece350z

Yeah removed the engine it kept flywheel on and removed the torque converter.. Would that explain my low compression though? No spark at the coils just 12v to them.. Weird how it started then cut out but now nothing?

PP08HR

iTrader: (2)

Yeah dude it's gotta be a timing issue unless your compression gauge is broken.

Reece350z

Thought so, I have no idea where I'm going wrong.. The #1 is at TDC and crank marks line up and can shafts have the right circle and oval marks lining up so what else am I missing?
Any ideas? Thanks for your replys!

Reece350z

Think it could be anything to do with the VTC solenoid. Timing is perfect so it's either the new head gaskets or rings

NissanZcrazy

iTrader: (1)

Your compression test showed that you only have 50 psi per cylinder? If that's the case there's a problem there for sure. However that doesn't explain the no spark issue.
You're certain you've timed the engine correctly?.I'm pretty sure these are zero interference engines. Meaning if you've timed your valves incorrectly you're going to bend them when you crank the engine over.

My advice would be if you don't know what you're doing when it comes to timing pay a technician to do it.Hopefully no damage has happened yet.

Reece350z

Yeah had the chains off again to recheck but it fired up when I first tried it? It's strange I'm thinking ecu now. Got 12v to the coils and good ground and signal continuity from Ecu to coils so it's the coils not sending spark. Going to try cps and cam sensors next and then the ecu. No other options left really.
I'm fairly confident, I was a technician myself for 2 years but the wage is awful, especially where I'm at

PP08HR

iTrader: (2)

Dude don't just guess at an ECU. If it was working fine before then it's probably not the ecu.


Tow it a dealer and pay their diagnostics. It'll save you some money in the long run.

Reece350z

Do you not think I could of sent a spike to the ecu? The puddle/lake was up the bonnet.. Was hopping to be my last option really but looking a strong possibility. Only 2-3 350z around my area, used to work with a tech from a Nissan dealer and he says they won't have a clue where to start because they never get to work on them..

Reece350z

So ended up replacing the crank sensor and it fired up straight away! But now I'm getting camshaft 2 sensor problem. P0345 twice and knock sensor signal low?
Took the car for a drive and was very sluggish so topped the auto gearbox level up and went to drive again and won't accelerate hard, feels like it hits the rev limiter and starts to splutter and back fire.. Any ideas?

iideadeyeii

iTrader: (6)

uhhh

Reece350z

Battery was fried which is why I had low compression..

PP08HR

iTrader: (2)

nope

zakmartin

You have low compression because gas (air) is escaping from the cylinder at the compression stroke. That means you have bent valves, bad rings or a leaking head gasket. That kind of thing happens when you hydrolock an engine. Hell, if you hydrolocked it, you might have bent rods on top of everything else. Stick a borescope through the spark plug holes and see if there's any obvious physical damage.

KJFire4Life

iTrader: (6)

+1 for the bore scope, we have a snap on one and one that attaches to our iphones at work!!!! Worth their weight in GOLD. But all things aside.......re-do your compression test before you drive it again. All plugs out, battery on charger or jump pack, 3 rotations per cylinder test. Post us some numbers. If you hydro locked the engine and DIDNT take the heads off to check them, then I applaud your bravery.........

travlee

iTrader: (8)

KJFire4Life

iTrader: (6)

I can't breathe For some reason this just made my day lol.

Reece350z

In my top post I did say that I had changed a Conrod which was bent.. After compression testing on the battery which was fried I was getting 50psi across all 6 cylinders.
After changing the battery and re doing the test I got 170psi across the cylinders.. Car was barely cranking on the battery.. Car starts fine with no misfires just doesn't rev properly.
Thanks for everyone's advice I appreciate it. Any ideas with the revving issue?

KJFire4Life

iTrader: (6)

Revving issues could possibly be due to an electronic throttle issue. Try resetting the throttle position in accordance with the FSM! Reset the ECU if you haven't done that? What happens when you floor the pedal? Hesitate at all? Any other issues that would help narrow it down? Revving by itself could also be do to a bad sensor...... Reset and go from there