Good evening, hopefully you can help me with my car.

2 weeks ago the tensioner failed on my timing belt, (Dayco) fitted in 2023
i stripped it down and replaced the rockers and tappets as a number had failed
i leak tested the engine with the camshafts off and it held pressure, once i put it back together i did a compression test and all cylinders looked equal and good.

i put the rest of it back together and primed the fuel system. unfortunately it wont start. i checked the lines next to the injectors and fuel was coming out of them, so i assume they are primed.
i plugged in my obd2 system and there was no error codes. i tried with SDD too and this had the same result.
the pressure got to >2500 bar which i assume is plenty.
i tried a little easy start and the car ran on it no problem.
i got desperate and pulled the injectors out and ran them, hoping to see fuel spraying everywhere. unfortunately i didnt see any fuel spraying.

i numbered the injectors when they came out so they went back in the same positions as i knew this was an issue.
i changed the crank sensor when i rebuilt the car, as the sensor was damaged, i ordered another and tried that, unfortunately this made 0 difference.

later on i looked at the manual and it said not to put the injectors on their side when stored, unfortunately i put them in a box, so i didn't do this.

i'm not convinced i dont have an air leak somewhere, but i can't see any leaks.

any ideas what to try next? what triggers the injectors?

does. your rev counter move when turning engine over ? And unless im mistaken the fuel pressure seems low to me im sure others on here will correct me if im wrong have you checked the wiring to the crank sensor as this can be easily damaged, the engine will not start unless its receiving the correct signals from cam sensor or crank sensor. you should also remove crank pully and check the crank sensor ring is ok
apologies for the long list but all need checking it'll be something simple its just a matter of elimination

The long list is great, I'm at the end of my list of things to do to be honest!
What pressure should the fuel system reach? It rises quickly and then falls at speed once you stop cranking. I assume a valve opens to allow the fuel to return.
I believe the wiring is okay on the crank sensor I disconnected the sensor and got an error when cranking, and tried the same with the sensor hanging loose and got another.
The trigger wheel was full of belt but I cleaned it up and it looked okay. I checked it wasn't on backward too. Is there any way these can fail? I saw that they're unavailable as replacements
When its all together no error codes are created on both new sensors.
I have a new camshaft sensor on order, but I'm thinking fuel issues are the most likely.

Sorry, yes the rev counter moves when I turn it over. I unplugged the crank sensor and it still moved. I assume this is triggered by the cam sensor?

unless im mistaken the fuel rail is permanently open until switched by the ecu then high pressure builds and injectors receive fuel, something is telling the ecu not to close the valve on the rail (the one on the right) have you checked all connectors are fitted ok take them off and refit them again

you could try supplying the sensor on the top right of the fuel rail with 12v you should hear it click when voltage is applied I once had a sensor that had frozen and doing this freed it and car started its worth a try but only do it quickly to see if it clicks don't leave 12v on permanently as I think they only need about 9v

There's a chance that something isn't connected right. The car was in a hundred bits, I'll keep checking connectors. I would assume the car wouldn't build any pressure without the valve closing, but maybe it's passing a little. I'll have a go at powering the unit up. Is got to be something simple like this, these ideas help a lot!

did you connect the plug on hp fuel pump its underneath and awkward

I don't remember disconnecting it. I just unbolted and moved the pump to the right. I assumed it was a mechanical device. I'll have a look for this to see if I disturbed it.

The pipe between the filter and the pump seems to have air at the high point despite me bleeding it through, it seems to return.
The pump to the rail is metal pipe, so could it be a seal on this line causing an issue? I assumed if the line was full when I cracked it id get enough pressure to fire.
No visible leak so maybe its coming elsewhere

it won't fire up unless the sensor closes and lets fuel pressure build try the 12v on the top right sensor I know its a bit of a bodge but it has worked for me in the past just use a couple of small croc clips on the pins I usually bleed the system through the fuel return pipe the green connector pops of easily just above fuel filter

Boxa wrote:

you could try supplying the sensor on the top right of the fuel rail with 12v you should hear it click when voltage is applied I once had a sensor that had frozen and doing this freed it and car started its worth a try but only do it quickly to see if it clicks don't leave 12v on permanently as I think they only need about 9v

okay, i've had another play with the car. I had to bleed the system again unfotunately as there was some air in the system. i pulled it through the filter return till there were no more bubbles.

i checked the return valve on the rail, and it activated fine, i put a bottle on the return and cranked it. it seemed to hold pressure till the engine stopped cranking then it relieved pressure.

the OBD software showed 4249 bar this time so hopefully enough pressure.

i did notice that torque shows my throttle position at 83% no matter where it actually is. i looked in the settings and there was another throttle readout that showed the position correctly. could this be showing me something important that isn't working?

the throttle body was replaced a couple years ago and no issues before the car failed. i've checked the connectors and they look okay, they were not unplugged when I did the works.

I have had throttle body problems in the past and if it's stuck closed the car won't start. it might be worth taking it of and remove the side cover to see if gears have stripped. can you hear it making noises when you switch ignition on ?

the throttle body could be the next thing. the camshaft sensor turned up so i plugged it in, no difference.

my oscilloscope turned up and apparantly is safe for 400v so should be enough to puck something up.
i tested it on the camshaft sensor and it seemed to output pulses, so i tried the same with the injector. no power going to it at all.

something isnt giving the car the required signals to fire the injectors. is the logic written out anywhere? i'm thinking if i can pick through them i can cross off the items one by one.

I've just had a quick read. the car should also be put in park. the RAC man ragged my gear selector when he was trying to move it and the button is no longer moving, i assumed it was just a spring broken and fairly low on my priority list. the dash shows the car is in park though.

could this be the issue??