Since getting the engine running on this car it has a fault where the Lambda sensors throw a code. Initially this was pretty continuous, but after significant work it is only if the engine has been left idling from to get fully warm.
The idle is a bit lumpy when running in closed loop, but becomes smooth when the ECM light comes on and the ECU switches to open loop.
The list of works includes testing and changing both lambda sensors, (twice for the front one).
The only item I can't guarantee yet is vacuum, as my gauge is faulty (new one on order), but a pressurised smoke test revealed only a very slight leak at the front throttle spindle, so I doubt that is an issue. When the idle bypass hose is blocked sharply the engine stalls immediately, hence I don't believe leaking air is the issue.
All intake and exhaust smoke tested.
I checked the Lambda sensor outputs with a scope and the front one indicates a lean mixture, which is comensurate with the faulting idle.
I need to check compression, but don't think it's that as the engine is smooth and appears to have compression when cranking.
Fuel pressure seems to remain when switched off, and I can't see low pressure affecting idle but not running.
New HT leads, distributor cap and rotor arm.
Additional earth added into the loom as the TPS, water temp sensor, MAP and air temp sensor weren't reading their proper output due to floating Gnd line.
I have read through Dean's thread and note his faltering was HT related, but that was when under load.
I haven't changed the IGN module or coil as the spark is strong and the engine runs well, apart from the faltering idle.
I changed two duff injectors and serviced tham all.
I haven't been able to road thest the car.
Vac appears good, as it meets Citroens recommendation that the engine revs should fall below 500 Rpm when the idle bypass is blocked.
Injectors are good
All wiring is good The loom is a bit aged and has some cracking insulation near some connectors (TPS, CKP, engine position, Water temp sensor), but I don't believe there are any electical conductivity issues, as I have measured the signals at the ECU.
All sensors are good. New Coolant temp sensor, MAP sensor tested with Vac, TPS measures less than 0.5v at throttle closed.
O2 sensor ok. Tested and replaced.
The fault behaves like a vacuum leak, whereby the greater the air restriction, the more exacerbated the issue is.
I'll perform a proper compression test this week and a vac test when a new guage arrives. The ease of starting and lack of smoke indicate it isn't a compression issue.
Matthew, you had a contact for cheap ECU's. Do you know if they have any for a prV6-24?
Does anyone have a wiring loom spare?
Also required is a V6 dipstick...or accurate measurement so I can make a new top for mine. I don't think this is the running issue.
What version of Lexia hardware and software is needed to retreive live data from a Fenix-4 ECU? Can the later, W10/USB software run a Mux that will communicate with Fenix-4?
Would the appropriate K-Line connections give output to OBD2? (for available functions).
Citroen OBD2 connections.
Pin Signal Description
2 J1850 Bus+ K-Line of heater and air conditioning system
3 RPM Engine RPM signal
4 CGND Chassis ground
5 SGND Signal ground
6 CAN High J-2284
7 K-LINE Engine and Gearbox (ISO 9141-2 and ISO/DIS 14230-4)
10 J1850 Bus- Electric power steering wheel diagnostic
11 K-Line K-line diagnostics of the anti-theft system; Tire pressure monitoring (for 307, 607, 807 and some other models)
12 K-Line ABS (Anti-lock Braking System) diagnostic
13 K-Line Airbag diagnostic
14 CAN Low J-2284 / K-Line Central door locking system
15 ISO 9141-2 L-LINE L-line diagnostic of engine and gearbox (ISO 9141-2 and ISO/DIS 14230-4)
16 +12v Battery power
Lexia 3, MUX, lead connector, OBD2, connections.