Hi everyone,
I'm hoping that someone might be able to shed some light on my problem or give me some more ideas.
My van is a 2009 pre-facelift 2.5 BNZ 6-speed T5.
My van started having intermittent starting problems about 18 months ago. Sometimes it would start on the button but other times it would take a long time cranking before it would start and then would take a bit of a rev to smooth out. There seemed to be no pattern to when it would do it, when it was cold or hot, damp or dry, when it had been standing switched off for minutes, days or weeks. There was no noticable pattern. The cranking sounded normal apart from it not starting (i.e. it wasn't slow).
Then on one occasion I was sitting in a traffic jam with it idling for about 10 minutes and when I went to pull away it stalled. When I tried to start it again it just kept turning over but wouldn't fire. I spent about 10-15 minutes scratching my head about what to do. I tried it one last time and it started and ran fine.
It didn't stall again for a couple of months but when it did it was the same scenario. Idling/manouvering at low revs, go to pull away and it stalls. Won't start. Leave it 10 minutes and it starts and runs fine.
Progresssively the starting and stalling issues happened more often so I took it to my mechanic to fix it. He's had it for several months and can't figure out what's causing it. As it got worse we noticed that when it stalled it developed a misfire first which you could fight with the throttle but it would still stall. It's not throwing up any (relevant) error codes and we've eliminated the following theories:
Fuel cap Fuel tank breather Fuel leaks In tank fuel pump Battery Electrical connections Injectors (they were cleaned 2 years ago and have been tested a further 2 times) ECU (has been tested and given the all clear
Since the ECU was tested my mechanic has put it all back together and the symptoms have changed. It no longer has the starting or stalling fault but has a consistent misfire at low revs (c. 1500-2000RPM). We think this could be because the injectors have been removed and replaced and could indicate worn injector bores in the cylinder head.
Can anyone tell me how to confirm for definite that the injector bores are worn? And what are the options for repair? Can the bores be filled (weld or insert) and machined?
TL;DR: What are the symptoms and fixes for worn injector bores on a 2.5?
Thanks in advance.
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