Not firing after major work tdv6

[Bulletman]

Gday All

Looking at ideas on what possible causes are stopping the engine from firing after basically a top end rebuild. The engine cranks and has been bled as the manual says to do it so i can cross off the lpfp , plus i loosened the pipes on the fuel rail and injectors and have fuel at these locations.
Things i know that are right..
-Timing is good.. i checked it atleast 10 times and it was timed correctly
- the injectors were marked and stored in seperate bags and the electrical connectors were also numbered so im positive they are correct
- i dont have any electrical connection left un connected and am confident they are all connected to the right place.
- i dont have any codes showing.. im assuming a faulty crank or cam senser would throw a code even in the cranking stage ??

I have tomorrow off so will connect the gap tool and see if it reveals anything but my general thought are either the hpfp which is about 4 yrs old or a crank or cam sensor.. i cant think of much else that will stop it firing..

Any suggestion of things to check with the gap tool when i have it hooked up will be appreciated.

Cheers Bulletman

[loanrangie]

They can be hard to bleed from what i've read, mine only took 2 or 3 cranks to fire up after having all the injectors and fuel lines off.
GAP tool will be your best bet.

[DazzaTD5]

when you say you bled it....

as noted some fire straight up, others not so.

I bleed the line from the Schrader valve that I connect a clear tube going to a gauge that has a pressure relief button on it.
ignition on sit there and watch for all the air, noting the pressure from the low pressure pump, 6 - 8 psi, wait for the pump to time out, ignition off, repeat until there are no bubble left.
this might be anywhere from 10 times to 20 times.

*Injectors dont need to be marked 1 - 6, its nothing more than a best workshop practice when working on lots of different engines.
*unlikely a failed cam or crank sensor unless you have damaged them or wiring.

[shack]

As above...

And I'd be hooking up the gap tool, find rail pressure and see if it's building when you crank... Mine wasn't after I had some fuel system parts off, I had to replace the HPFP.

I think one of valves maxed out when trying to build pressure and stayed there, or the inverse of what I just said.. Either way it wouldn't build pressure.

[DiscoJeffster]

When I did my injectors, I ended up killing the battery such that the vehicle would crank, but the voltage was dropping low enough that the ECU wasn’t firing the injectors. I think Dazza has it, but worth considering battery health as well for the extended cranking.

New battery and started up after a short crank cycle.

[Bulletman]

Ok so im positive its not air in the system.. i had trouble making shrader valve fittings work without ****ing fuel out so i removed the valve centre and i filled a couple of 1ltr glass jars with no hint of airation and i dont have a pressure guage but how easily and quickly that filled would tell me the lpfp is certainly pumping plenty of fuel.

Connected the gap tool and the fuel pressure rised to 630kpa but fluctuates between about 480 and the 630 the longer i crank..

Are there and other things i should be checking..

The only faults logging is a suspension fault as the car is on the bump stops.
The battery is fully charged and is only 6 months old so im positive its not voltage related

Any suggestions greatly appreciated

Cheers Bulletman

[Bulletman]

Ive gone back and rechecked the timing and that is definately correct.. i guess next step is change out the cam sensor as im guessing thats something that could stop it running altho i would suspect it to show as a fault but maybe that only happens if/when the engine is running ..

Cheers Bulletman

[DiscoJeffster]

You’ve got a gap tool. Use the live data and read the sensors and confirm the signals are showing. Plot them.

[Graeme]

Watch or graph the rpm while cranking to determine if the crank sensor is working.

A faulty camshaft sensor should log a fault if the crankshaft sensor is working but no faults logged if nothing from the crankshaft sensor.

[Bulletman]

I may have found a problem ... both the solid high pressure pipes that go to each fuel rain are leaking at the hpfp and its possible the pressure drop is enough not to fire the engine.. couldnt really tell i had the leaks till the boss arrived home and had someone to crank the engine whilst i could have a close look.

Trying to tighten them turned into damaging them but i did notice the fuel pressure did increase up to 1300kpa before i stopped and called it a day

Funnily i dont seem to have the fuel rail pressure option on my gap tool....

So its now source some pipes and those bloody fuel return line clips as 2 of those bloody things disappeared into the depths of the engine..

Cheers Bulletman