Posted by Peter Holland on October 29, 2012, 9:38 am
Year of Manufacture *: 2005 Engine Size and Code *: 1.9 PD BJB ( Optional ) Scanner Used: Vag-Com ( Optional) Fault Codes: None
My customer had this vehicle recovered to me as a non runner after it refused to start out side his house. It was fine before, with no running faults at all. No fault codes stored.
I've checked fuel delivery and replaced the duo pump after checking fuel pressure at the pump. The pressure would just about reach one bar when cranking, but I was unable to clarify is this was too low. VW Erwin mentions that the pressure should reach 7 bar at 4000 RPM. Local diesel specialist mentioned around 5 bar. So, after fitting a new pump this pressure has increased to 1.5 bar when cranking but still no start. There is no sign of diesel in the sump which would suggest injector seal problems. If I run the engine on easy start, the pressure goes right up.
So, next I've tried to check injector pulse etc but not having done one of these I don't really know if what I'm picking up is correct. Being the 1.9 engine that uses the earlier electro magnetic injectors I've been able to check injector resistances back to the ECU. All check OK. The injector pulse is shown below. Autodata Pin out just mentions check for 2.4 volts on all 5 wires to the injectors. This can be seen in the scope trace.
Has anyone scoped one of these before? If so, is this correct? What I can't get my head around is that I get this pulse off of all five wires (one common to all 4 injectors and then four switch signal wires to the individual injectors) so I don't really understand whats going on. Not very satisfactory conclusion to give to my customer!
Hi, Had a few of these and if you disconnect each injector in turn and try and start it. If she runs the disconnected injector is faulty. Hope this saves you time. Shane
Shane, I think that only works on the later 2.0L PD engines with the piezo injectors. They appear to be the ones that are suffering with internal short circuits etc as a result of using the wrong engine oil which causes the insulators to break down. That's what I've been told anyway.
231 /min Engine Speed (G28) 0.0 mg/str Injection Quantity 3.1°KW Injection Duration (specified) 51.6 mg/str Start Injection Quantity 48.0 Start Synchronisation 380.0 mg/str Mass Air Flow (actual) 128.0 Injector Status Cylinder 1 128.0 Injector Status Cylinder 2 128.0 Injector Status Cylinder 3 128.0 Injector Status Cylinder 4
I'm struggling to find much live data that gives much info as to what the injectors are doing, but I'm a little confused by the injector quantity reading 0.0 mg/stroke when cranking!
Here's a complete vehicle check result.
Thursday,01,November,2012,11:55:34:39618 VCDS Version: Release 11.11.4 Data version: 20120807
I took a gamble with this one in the end after extensively checking the ECU wiring etc and found a second had unit on ebay. A local VW specialist reprogrammed it for me and it fired up! Happy bunny now.
This is what the injector pattern should look like.
Its a bit of an odd pattern. The amps and volts probes were picking up off of number one injector. It appears that the ECU switches the common positive feed to all injectors as its needed as well as switching the individual injectors on the negative side, so you never get a constant 12v on the common connection to the injectors. Very weird! This trace shows the negative switch to that injector.
on October 29, 2012, 1:55 pm, in reply to "