Swapping injectors

[KILOCHARLIE]

My l322 now refuses to run on lpg and my software is saying injector 8 error. I'm hoping its possible to swap the injectors around, say from cyl 8 to 1, to see if the error swaps so that I can confirm it is indeed the injector at fault rather than anything else. Does anyone know if this is an easy job? Do i have to remove the rails?

My injectors are magicjet 3's. Is it just the brass injector that needs swapping or is there something else underneath?

Thanks for any help guys!!

[rossko]

First be sure if you are looking at petrol injector (input) or gas injector (output) issue, assuming you are talking about an LPG software complaint.

Bear in mind the petrol management may shut a cylinder down due to say misfires - the LPG system will then complain of missing input injector pulse.

[KILOCHARLIE]

Thanks for the reply and apologies for the delay in replying. I subscribed to the thread but didn't receive an email notification.

I've checked and its definitely the gas injector causing the error. The code is gas injector error 8 on the stag software. Can I just swap the injector by leaving them on the rail but swapping the electrical input and the gas hose going to the cylinder? Ie if I swap 7 and 8 and see if the error follows?

The car seems to run ok when idling but any load and it beeps and cuts out making me think its a split hose or loose connection although a visual check doesn't indicate anything.

Thanks for any help.

[LPGC]

Can I just swap the injector by leaving them on the rail but swapping the electrical input and the gas hose going to the cylinder? Ie if I swap 7 and 8 and see if the error follows?

The car seems to run ok when idling but any load and it beeps and cuts out making me think its a split hose or loose connection although a visual check doesn't indicate anything.

Thanks for any help.

Yes you can swap the wires and pipes over.

Sure there isn't a misfire at idle too?

The wires between MJ injectors and the electrical connection can easily be broken at the injector end so it's particularly important with them to ensure wiring connections aren't pulled tight or broken by fatigue due to vibration etc. Not definitely the cause (have known MJ coils to go wrong / Stag output channels to go wrong) but likely. A wiring fault at the injector will still call for a new injector anyway.

If you change the injector, swap the nozzle from the old injector onto the new one. The X5 should have nozzles fitted on MJ injectors but some installers try to get away without drilling fiddly MJ nozzles on engines with 550cc cylinders (just about OK with reducer pressure set low enough with this capacity cylinder). If your injectors don't have nozzles fitted it might seem an easy swap to remove the nozzle from the new injector and fit 'as is', but be advised some MJ injectors seem to flow more than others without nozzles (different batches) and if you get one that flows more or less than your other 7 this one cylinder will run richer or leaner than the others.. It is possible to see how each cylinder affects fueling by turning each on/off in turn in the software - Without nozzles fitted, if you find a new injector affects fueling more than the others, the best way forward would then be to fit drilled nozzles and re-calibrate the system. If you have nozzles fitted the bits above relevant to 'without nozzles' won't be a concern, the nozzles will govern the flow so all will flow the same.

Simon

[KILOCHARLIE]

Many thanks for the info. I've just swapped injectors 7&8 over to see if the error follows but somehow the error still stays as "gas injector error 8" even after clearing all errors and starting the car again. I'm guessing the injector isn't a fault then but no idea what else it could be. I've recalibrated again to rule out a software fault but no luck there either I'm afraid.

[LPGC]

There is no guarantee that the installer connected LPG channel numbers to the same respective cylinder number. Sure you swapped 7 & 8, not (say) 3 & 4? Gas injectors 1 - 8 wiring colours respectively are yellow, green, red, blue, orange, violet, brown, grey.

Another test, just to make sure, could involve pulling the plug from every injector and checking the electrical resistance across each.

Other than that you could check the loom itself - grey & grey black wire at the LPG injector plug to relative pinout at the ECU end of the loom. Don't know which Stag ECU you have so can't quote ECU pinout yet.

Wouldn't be the first Stag ECU (or plenty of other make ECUs) I've known go down reporting failed LPG injectors in this way.

Simon

[KILOCHARLIE]

Thanks Simon, I'll give that a go tomorrow night and keep my fingers crossed!