Clue to me is in where you said your cable works perfectly with your Leonardo and Millenium ECU's - Those ECU's will have the 8 pin (only a few pins used) Molex type connector as opposed to the later AEB type 4 pin Supaseal connector. Tartarini systems that use the Molex connector have a different pinout on the connector (some of the pins on the second row are used as opposed to other AEB systems that use pins all on the same row).

Your cable will work if you just chop into 2 wires on your interface (the wires that are not connected by the Molex connection) and the relative same wires on your LPG system's interface connector cable - just make a temporary patch using bits of wire to make the connections that your Molex connection isn't making. You should be able to compare wire colours to your Leonardo / Millenium system. Or instead of messing with USB to serial dongles, chopping into wiring or buying a cheap supposedly Tartarini specific cable you might prefer to buy a proper AEB USB to Supaseal cable and a AEB Supaseal to Molex interface adaptor. The Molex connector on the adaptor is wired for both normal AEB type Molex connectors and Tartarini type Molex connectors.

There's a few versions of the software but i found the only one that works is the one i gave you for download which is for sequential systems.

The links Lpgc has put up are the ones he sent me. I have these cables and they work perfect.

Thanks guys, that’s most helpful.

On my car, the connector is just beside the ECU, it’s an 8 pin Molex connector that’s there. Does that mean i don’t need both of the cables in the link above?

As it’s been said in a previous post that i shouldn’t need to calibrate it, I’m tempted to just rebuild the reducer and fit the new filter and give it a try before spending another 50 quid on the cable.

David.

If you bought the AEB cable you'd need the adaptor too.

As said, you can use your cable but you'd need to make the mods I talked about. If you look at your interface Molex and your LPG system Molex the pinouts don't match up, you'll have a couple of wires that connect when you plug the Molex ends together but will need to (at least temporarily) hardwire the couple of wires that the Molex connection doesn't make (because Tartarini Molex pinout is different to other AEB system Molex pinout).

Or you could buy another 8 pin Molex connector and wire it to your LPG system, that way you'd wire the new Molex plug the same as your Leonardo system's Molex plug so and it would work with your existing cable.

That’s great, thanks very much for your advice.

I can probably get a couple of molex connectors from work so I’ll have a go at that rather then dropping 50 quid on the cables. If I need to, I will, but if I can get away without it just now then it’d be preferable.

The VSE is outside at the front of the house at the moment where there’s not much light, due to working yesterday and today, I’ve been mucking around in the dark, I didn’t even think to look at the pins in each end of the plug. Simple things eh!

David.

Difference between AEB (Leonardo and Millennium) and Tartarini connections

That’s brilliant, Gilbertd, thank you!

Hehe I thought Gilbert might post with wiring diagrams, nice one ;-)

Can see on the diagram how it's possible to wire a single Molex plug to work with both the usual AEB connection and the Tartarini connection, you just need the 2 additional pins on the 2nd row connecting to work with Tartarini.

Right, tonight I've made a little extension lead for my LPG cable. It pins out exactly the same as the cable that Gilbert posted above yet when connected to the car still has a no communication error.

It's pitch dark up here and wet so I'm not spending any time on it tonight. I've just found out that I'm off work tomorrow so I'll have a play around tomorrow hopefully.

The Tartarini software doesn't seem to let you make many changes to the setup, has anyone else used it with a USB > Serial connector? Does it matter what port the connector is set to on the PC?

David.

dhallworth wrote:

Right, tonight I've made a little extension lead for my LPG cable. It pins out exactly the same as the cable that Gilbert posted above yet when connected to the car still has a no communication error.

It's pitch dark up here and wet so I'm not spending any time on it tonight. I've just found out that I'm off work tomorrow so I'll have a play around tomorrow hopefully.

The Tartarini software doesn't seem to let you make many changes to the setup, has anyone else used it with a USB > Serial connector? Does it matter what port the connector is set to on the PC?

David.
I've not, but generally sticking to a com port number lower than 4 is best. If com1 is free use that.

You should be able to use device manager in windows to change the port assigned to a usb adapter anyway, but sometimes it will assign a much higher number than you might expect if the machine has seen other serial devices in the past (usb to serial leads, mobile dongles for internet use etc) even if those devices aren't actually currently connected.

I've checked all that and it's assigning my adapter to COM5, I'm just wondering if the Tartarini software is expecting to see it on a specific port and that possible a reason that it can't connect to the ECU.

I'll give COM1 a try tomorrow and see how I get on with it.

David.

I've just looked in my software. There doesn't seem to be a manual option to change com port. When i do it by usb, it just auto detects. Perhaps you're right in saying it's expecting to see it on com 1.

When you've connected, it'll automatically download your settings and then you'll be able to change stuff.

Early software might need low com port numbers, later software usually works on just about any com port. Early software may need com port selection.

Depending on age of ECU you might need early / late software. Latest software is version 6 and is the most compatible version (works with most year ECUs unlike say V5 which is less likely to work on very early or very late ECUs) so V6 software is a good bet.

Pulling the LPG ECU fuse can sometimes sort connection failures (after putting the fuse back in of course). Molex pins soon get corroded if exposed and can even snap off sometimes leaving the snapped pin in the female end. You'll have noticed in Gilbert's diagram that the Tartarini Molex is pictured the other way up to the other system Molex. Some interfaces (mostly out of those that use USB to serial dongles before the actual interface but also some USB ones such as ESGI's own brand cable) which work OK with Leonardo's won't work with sequential systems, these tend to have 3 wires to the serial connector at some point in the chain as opposed to 4 wires.

The rebuild kit for the vaporiser and the new filter arrived today.

I rebuilt the vaporiser and swapped out the filters and then refitted them to the car. The diaphragm in the old vaporiser didn't look that bad, nowhere near as bad as I thought it might seeing as it's been on there for 12 years. Anyway, after bleeding the cooling system through to ensure there were no air locks I tried the LPG.

The car switches to LPG and idles ok, if you rev it gently it revs fine, however if you open the throttle quickly it switches straight back to petrol and the switch beeps at you.

Here's a video of what it does:

https://www.youtube.com/watch?v=Fmo25KW6IDc

I've got a feeling I know why my cable isn't working but haven't had time to check it. I made my new cable with Gilbert's diagram looking at the front of the plug, looking at it again and chatting with Gordon about it tonight, I think that picture is of the back of the plug so my connectors are in the wrong place.

Going by the mileage on the car and the mileage on the receipt for the LPG conversion I reckon it's done about 80k on LPG. The owner that I bought the car from reckons it's been a gradual deterioration on LPG rather then an overnight one.

David.

You'll be able to tell more when you're able to plug it into the computer, but in the meantime, check that you haven't got a dent/ pinch in your gas line from tank to vapouriser.
Obvious question though- have you actually got a decent quantity of gas in the tank? The gauges on LPG are more of a wish list than a reflection of reality.

As OB said you'll know when you can see readings but it'll probably need the reducer output pressure turning up.

I can't remember if the pictures of the connections are of the plug on the cable or the plug on the ECU. Easiest way to check if you have a Leo/Millennium is to identify the 12V pin and work the others out from there.

Gilbertd wrote:

I can't remember if the pictures of the connections are of the plug on the cable or the plug on the ECU. Easiest way to check if you have a Leo/Millennium is to identify the 12V pin and work the others out from there.

Your diagram shows pinout looking from the rear of the interface cable plug, or to put it another way the diagram shows pinout looking at the LPG ECU's plug from the front socket end. I just compared to one of the AEB interface adaptors I linked to above.

Well, I've tried it again and am still not having any luck. The cable is definitely correct, I've tried 2 different USB > Serial adapters, two different laptops, and still getting no joy.

I'm wondering if it's due to the version of software I've got installed being Version 6.0. I know my ECU was fitted back in 2005 so it's probably quite an old one. Would if be worth trying Version 5.0?

Does anyone have a link to Version 5.0?

David.

Wouldn't have thought it'd make a difference. In the interest of thoroughness though, i've uploaded V5 for you here

I reckon you need to get the right cable.