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While compiling the servicing info for the new toy I found that the Zavoli/ Alesi system is nearly 11 years old and has covered 167000 miles with no attention apart from the occasional filter change. With many moving parts, solenoids etc I imagine some of them are a bit tired.
Suggestions welcome on what to change, ways to test etc.
Thanks

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Injectors and the reducer, but if they're working - they're working! Some last for 10 years some don't.
The thing to look out for is the tune which can/will slip over time. My Jeep had knackered exhaust valves/guides from years of lean running and that's an iron head.

The tank should (theoretically) be re-certified after 10 years but the only economic option is to replace it if you're concerned. If it's living in the wheel well and rust free, that's a different proposition to an underslung tank that has been covered in cr*p for 9.5 years. Up to you, really.

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Regulator diaphragm and injectors are the main things that wear out. Solenoids don't tend to wear although the plungers can get a bit sticky and the coils can go open circuit or crack allowing moisture to get in. Usual sign of worn injectors is that they clatter like a pair of castanets. Do you know what injectors are on it? Zavoli sometimes came with Matrix which last forever.

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I'm the master of the underslung tank (s) covered in crap Morat :)
I'll have to have a look at the injectors to see what make they are, I haven't had time for more than a cursory glance under the bonnet yet. It's such a dirty WD40 soaked mess under there that I shut it quickly after a check of the levels.
Magnacors and a new set of plugs now ordered which should improve the running somewhat.

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Assuming this is a Zavoli pulsed injection system...

There are a few basic checks you can do;

Pull the vacuum pipe off the reducer while it's running on LPG, no gas should come out of this port on the reducer.

Use a bit of pipe in ear as a stethoscope to listen to each injector. They should all sound similar, any that are much louder than others or making a fairly pronounced metallic noise are probably shot, although they could be shot even if quiet! Being a Zavoli system it will either have Zavoli's own injectors (either individual injectors or mounted on a rail with individual units easy to identify) or Matrix injectors (more of a square block, individual workings not easy to identify except for seeing gas outlets). Matrix are by far the better type in terms of both longevity and performance, they may further be identified by the single big square electrical connector block,

If you have a suitable scanner, check fuel trims are good and similar on either fuel. And/or check lambda readings under various engine operation conditions.

At 11 years old and many miles might expect even Matrix injectors to be a bit worn.

Even if you had the interface for the LPG system, diagnostics capabilities via the old Zavoli ECU will be limited, it is unlikely to have capabilities of more recent LPG ECU's such as ability to switch individual cylinders between LPG and petrol. Though a cable would allow you to adjust calibration of the system of course. For more advanced checks on parts such as injectors a more recent ECU could be temporarily swapped in.

Hope that helps.

Simon

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I think you've got a cable for the Leonardo on your other one so, if you have, that will work with the Zavoli. Software can be downloaded from http://www.vogelsautogas.nl/documenten/Software/Software%20Zavoli/Zavoli_6.1.1.0_cad.zip assuming it is the Alesi N and not the earlier Alesi. I've got a number of earlier versions if that one is too new.

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Thanks gents. I'll have a dig around under the bonnet tomorrow. Looking forward to plugging in the Nano to see what I'm going to have to do battle with generally, so will check trims on both fuels while I'm at it.

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Pics of what I can see of the LPG stuff:
enter image description here
One of the 2 gas injector thingys
enter image description here
The vapouriser thingy
enter image description here
The LPG Brain thingy

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Original Zavoli Alesei rather than the later Alesei N, Zavoli Zeta S reducer (the higher output one so that's good) and the ridiculously expensive but extremely good, Zavoli badged Matrix XJ544 injectors. A very good system that shouldn't give any trouble and even if it does everything is rebuildable.

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That's good to know. All I have to do now is find the diagnostics socket. Nothing obvious tucked in the old GEMS ECU box but a suspiciously loose wire with the end cut off in LPG control box loom.

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It should come out of the main LPG loom. 4 wires that SHOULD have an 8 way Molex connector with only 4 ways used the same as your Leonardo. No idea why someone would chop the plug off though.

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Not a Molex to be seen. Bolex :)

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Pretty sure I have those same injectors and ECU, but my reducer looks different ... probably an early one too.

My reducer looks like this (not pic of mine but similar one):
enter image description here

It switches on to gas OK from petrol, but doesn't switch back automatically.

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That's a Zeta N, a lower pressure version of the one OB has. As long as the injector jets are the correct size, then not a problem. It should switch back when the pressure drops so that would point towards a dodgy pressure sensor.

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So will the software you've linked to work on my system Gilbertd, or do I need to hunt down something earlier?

Gilbertd wrote:

I think you've got a cable for the Leonardo on your other one so, if you have, that will work with the Zavoli. Software can be downloaded from http://www.vogelsautogas.nl/documenten/Software/Software%20Zavoli/Zavoli_6.1.1.0_cad.zip assuming it is the Alesi N and not the earlier Alesi. I've got a number of earlier versions if that one is too new.

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No, you'll need the earlier one, I've just emailed it to you along with the installation manual and software guide.

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Brilliant- thanks

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Sometimes when plugs have been cut off it's because they corroded, so someone might cut the plug off to just screw wires together.

Agreed with Gilbert it could be a pre-N system, there is no N designation on the ECU sticker... but if it is pre-N it will be a rare example. Most pre-N systems have pressure sensor built into the ECU (so pipes attached directly to the ECU), most of the rest will have (at least originally) been fitted with the (external) AEB013 pressure sensor, even early N systems used the AEB013 sensor. Most pre-N internal and AEB013 external sensors will have failed by now, not easy to swap ECU internal pressure sensors but easy enough to swap an AEB013 for the later AEB025 type that is still used today (means swapping connecting plugs and changing settings in software though). Most pre N systems used ECUs with only 4 injector driving channels, for vehicles with more than 4 cylinders an external injector driver was (supposedly) added to the system (not always fitted, some installers bodged by just wiring 2 injectors in parallel to one driver channel).

Though V6 software will work on most N systems, some early N systems need software within a certain version range.

Pre N system ECU's work in a very different way to N systems, need different software altogether and are calibrated very differently. N type work as a slave to the petrol system, read petrol injector pulse duration and add fiddle factors as per user mapping to arrive at gas injector duration, so gas injector duration is calculated based on input from the petrol system. Pre N type work standalone, output specific gas injector pulse duration described by the installer's map which is based on engine rpm and engine vacuum, automatic closed loop operation is afforded by connection to lambda input (necessity).

Simon

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The plot thickens then!
I'll have a more detailed idea of what I have when I pull stuff of to get to rocker covers tomorrow. I'll have a close look at how the LPG system is put together.

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Well, the pressure sensor is external to the ECU and looks like this:
enter image description here