Hello, newbie here.
I've had an old non computerized WJZ engined Partner van for many years and am about to swap engines but the only one I could find locally was a WJY with an electronic advance pump so I'm going to use my Bosch pump,lines and injectors from the original engine as the pump and injectors are fairly recent replacements.
Whils't glancing at the manual I realised that PSA would seem to number their cylinders from the flywheel end but looking at the pump and lines the output sequence of A B C D seem to be connected up to the injectors and only make sense as though No1 is at the timing belt end. Am I missing something here?
You are correct about the cylonder numbering but I cannot help with the pump. I believe Citrojim has some experience of the Bosch pumps and may be able to advise you. Good luck
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
Ai says.
You aren't missing anything—this is a classic point of confusion with French engines!
PSA (Peugeot/Citroën) officially designates Cylinder 1 at the flywheel/gearbox end. However, because Bosch injection pumps and pipe sets are generic equipment designed according to standard German/international conventions (where Cylinder 1 is at the timing belt end), the physical pipe routing can look backward or counter-intuitive when mapped against French manuals.
Here is how it breaks down and why your original pipes fit and work correctly:
PSA Engine Cylinder Convention:
Cylinder 1: Flywheel / Clutch end
Cylinder 2: Middle-rear
Cylinder 3: Middle-front
Cylinder 4: Timing belt end
Firing Order (1-3-4-2):
Expressed in PSA convention (Flywheel = 1): Firing order is 1 - 3 - 4 - 2.
Expressed in Bosch / Standard convention (Timing belt = 1, so PSA Cyl 4 becomes Bosch Cyl 1): Firing order is 4 - 2 - 1 - 3.
Why the pipes look like they run to the "wrong" cylinders:
Because the crankshaft throw intervals (180° apart) and firing interval of a 4-cylinder engine are symmetrical, firing 1 (Flywheel) -> 3 -> 4 (Belt) -> 2 is mechanically identical to firing 4 (Belt) -> 2 -> 1 (Flywheel) -> 3.
If you are reinstalling your original WJZ Bosch pump, hard lines, and injectors as a matched set onto the WJY block:
Keep the pipes in their factory shape/set: As long as you transfer the original WJZ pipe set as an undisturbed bundle, each pipe will naturally reach its corresponding injector port without twisting or stretching.
Pump Timing: Ensure the pump body is timed using the standard locking pin hole on the injection pump sprocket (8mm pin/bolt into the pump bracket).
No Pipe Swapping Required: Do not attempt to re-route or bend the metal lines to match "PSA Cylinder 1." Connect port A, B, C, D on the pump head to whichever cylinder nozzle the pre-bent steel line physically aligns with.
When swapping the mechanical WJZ pump onto the WJY block, double-check that you also transfer over the original WJZ crankshaft pulley/timing covers if there are any sensor offset differences, and make sure to plumb the mechanical stop solenoid (or transfer your immobilizer/solenoid housing) as needed.
As MIck said Citrojim maybe your man to shed his experience on this for a second opinion.
Husky. Thinking outside of the box is better than sitting in a dark one.
You should be fine if you use your original pump, delivery pipes and injectors on the replacement engine precisely as they were installed on the original engine. The firing order of the engines will be the same.
Many thanks, that was what I was hoping to hear.
Except the bit about swapping the crank pulley, I don't think there are any position sensors on the original WJZ(definitely hasn't got one on top of bellhousing above the flywheel),and surely the crank pulley is just a toothed pulley and would be the same? Plastic covers are the same on both and I don't bother with the top two as they're a pain when doing belt changes
Thinking outside of the box is better than sitting in a dark one.
