Astra G 2001 Z16SE cranking but no start / intermitent/ morning only

[TR0UBLESH00TER]

Good cranking (240 rpm checked with scope ) but no starting ,as a rule in the morning at first start .After 4 attempts it starts ,run fine all day ,maybe once in while no start .As the evening cold comes problem is back.
Changed from a working donor car :crankshaft position sensor ,camshaft position sensor ,ECU +immo +transponder ,coil ,spark plug & leads ,fuel pump .Checked wiring ECU to injectors / coil / relay .
DTC only P0335 Not present (0) No engine RPM signal
which I ve heard could be normal if you scan with engine stopped .
Any help is welcome ,I am out of ideas :giveup:

[Meat-Head]

Doubt it, for education or entertainment purposes , remove crank sensor, rubber seal, flick it at first cat you see shutting in your garden.

use 6' scaffold bar to tighten crank sensor.

what is battery voltage whilst cranking ??

[TR0UBLESH00TER]

Battery changed and charged ,sometime will start even battery is almost dead ,sometime don t start even batterry is on external charger .
Some googling reveal could be the wheel on the crankshaft who excite the sensor ,maybe
P.S. There is indeed a cat wandering in garage and is black :argh:

[autoden]

I would start with a new temp sensor and run a new earth to ecu outer case, and over back of injectors to pick up the earths from temp and airflow.. Bad earth was always a problem with these when they were new.

[Ashraf6119]

Have you done the Cylinder Compression Test............? You can also try starting it using bit of easy start and see if it will start or not...............

[hbt]

What kind of ECU is inside this car? Simtec ? delco?

[TR0UBLESH00TER]

@autoden :temp indicated is correct so I think temp sens is good ,also the ECU is mounted directly on the engine and there is just a little voltage between ECU and batterry ground while starting .There is no MAF on Z16SE engine
@Asraf Dont know how relevant is a compression test ,the car runs perfect as soon as it starts ,the problem is only in cranking/start phase ,usually in the morning
@hbt Delco ,but think it is not the case ,checked from working donor car.
@ALL :This car is a rabbit hole to hell to me,now I regret that I get involved in , more than 2 weeks from job beginning .The garage owner where the car is isn t very convinced about my diagnostic based on the only one DTC showed (No RPM Signal ) ,he insist that is some wiring problem (already checked a lot )
The remaining option is maybe some mechanical fault with no DTC and the No RPM signal DTC was just a fake clue ..will keep updating in the next days

[smirnoff_rules]

My money's on ecu very common fault , best get an ecu / key and ring from junk yard cars not worth a lot


Sent from my iPad using Tapatalk

[lush29]

Try to heat up with aer blower ecu before you start in the morning see if that changed

Sent from my SM-G925F using Tapatalk

[Meat-Head]

Try to heat up with aer blower ecu before you start in the morning see if that changed

Sent from my SM-G925F using Tapatalk

And/or chuck a bucket of water on it.

can you unplug crank sensor measure the ecu homage, (i~~~~ Failiure) then run and repeat experiment

[lush29]

And/or chuck a bucket of water on it.

can you unplug crank sensor measure the ecu homage, (i~~~~ Failiure) then run and repeat experiment
I am not messing had one meriva and took few minutes to start in the morning.i open ecu to check for damage and then blow with hot aer put on the car and start first time till few hours. And not only ecu.

Sent from my SM-G925F using Tapatalk

[number7hd]

change fuel filter cover. Or replace original filter and cover on anotherone. I had many OPEL's with this problem.
Fuel filter cover isn't as tight as before so fuel goes to fuel tank by the night.