06 Quest SE VQ 3.5 V6 L Timing Question on Crank No Start

[Pauli925]

Cranking No Start Scanned with my TOPDAN Scanner Live Data Showing at 110 BTDC Have done this timing chain reset before as you may know its some work and have to pull the alternator and roll the power steering pump back along with pulling the harmonic balancer and that passenger motor mount to get timing cover off to set set everything back to #1 TDC
Just want to get some feed back on this before I do this Again To Get Restart

[VStar650CL]

They all show weird numbers when the engine isn't spinning, but should go to something normal when you crank. You can't tell a lot from spark timing because it derives from the crank (CKP), you really need to monitor the cam sensors (CMP's). Teeth on the chains tend to give you around 3 degrees per tooth when they jump, so anything more than about +/-2 degrees during cranking generally indicates a problem (ideal is zero). If both cams are off then it usually means the main chain, if only one is off then it's a sub chain. The resolution on your graph isn't good enough to tell what's really going on, and as mentioned, spark timing doesn't tell you much anyway.

[VStar650CL]

PS - If only one cam is off it can also indicate a bad sensor. Nissan ECM's are only good at identifying flatlined sensors. They're terrible at identifying sensors which are working incorrectly, and a lying cam sensor will definitely cause a no-start. Only streaming the cam data will tell you that.

[Pauli925]

Will see if I can pull a stream on the Bank 2 and Bank 1 Cam Sensors with my TOPDON Scan Tool
Also would it be a good idea to backprobe them on my Hantek Scope look at them during cranking?
My crank sensor is covered by hard plastic on back of it cant really get at the wires to backprobe there

[VStar650CL]

If the engine speed is reading smoothly and correctly during cranking then chances are the CKP is fine. If it's bouncy or zero then suspect a problem.

[Pauli925]

Have the Timing Reset was off for sure
Now Chain at timing marks for crankshaft and Banks 1&2
It’s dead on and cranks at 1 degree before TDC
Still have No Start Condition with Tach RPM’s far below what it should be which is around 800 to 1000 Rpm’s
Live shows 150 to 160 rpm’s
Time to find a way to backprobe that crank sensor and get my Oscilloscope on it check signal wire for integrity make sure no short or open circuit there before I call this for a new Crank Sensor and need to Scope the bank 2 Cam Sensor as well
That’s my direction far as I can see to get a restart right now

[VStar650CL]

During cranking 150~160 RPM is only a little low. Most Nissans crank around 300 with the plugs pulled and 190~250 with compression. So she's slow, but probably not enough to cause a no-start. RPM readings on just about all older models come straight from the CKP, so it could be reading slow because the CKP is skipping some reluctor teeth. That can cause a no-start.

[Pauli925]

]That’s all good to know
This is the Proceedure to test with Scope for Signal
integrity
https://youtu.be/Ht12mWdrNbU?si=tXw3yqoUwavs93Fq

[VStar650CL]

Yah, ScannerDanner is a pretty cool resource. You might find this link useful too:
https://www.scannerdanner.com/forum/dia ... forms.html

Rotkee also has a very nice signal library, much of which can be accessed for free:
https://rotkee.com/en/waveform-library?brand=190

[Pauli925]

What should the Voltage read at on the Crank & Cam Sensor Signal Wires on my Multi Meter? And while Cranking?

[VStar650CL]

Because the crank has a crapload of teeth and is fairly symmetric, the run voltage will typically approximate the ECM pullup voltage (battery voltage on your '06) times the duty%, which is about 20% per tooth. So your VOM will probably read a tad less than 12 x 0.2 = 2.4V when cranking. The cam sensors are very asymmetric and spend a lot of time over metal, so the exact reading will be a lot lower and not easily predicted. VOM's just don't tell you very much when you're dealing with Hall sensors. Obviously you can tell if they're flatlined, but you really need a scope to see vagaries in the signals.

[Pauli925]

Hey Guys Update on this the Crank Sensor Connector was full of oil inside blocking signal to the ecm I cleaned it completely with dishwasher soap in water in a spray bottle (this breaks down all oil and grease) dried it completely then to make sure was dry after sitting a while airing out sprayed it with CRC Electric Parts Spray to be sure connectors where dry

Then assembled and got restart After checking it would keep starting changed out the crank sensor and Bank 1 & 2 Cam Sensors because I have them all under Autozone Lifetime Warranty

[VStar650CL]