Disco 3.5 V8 Efi Cutting out on LPG

[sharpy1980]

It's a 91 and has a 100l 4 hole tank in the boot and I think a Tartini module on the bulkhead and a mixer bit on the air intake (I will add more info on it tommorow), basically when driving on Lpg it tries to die and cuts out but if you ease off the throttle you can sometimes save it before it dies but it holds back and if you switch over to petrol it drives fine.

It done this a while back but rectified itself on its own until now, during the time it was running ok I noticed on removal of the air flow meter it was completely hollow with no mesh or fine wire as i was expecting (is this normal)? Also during the good bit the downpipes were replaced so the lambda is no longer fitted but it didn't alter the running whatsoever (this normal)?

I have contacted a local specialist and they want £50 to look at it plus any parts it needs but what worries me is they said if the system is old they would probably have to replace everything but the tank (don't fancy taking it there).

Any help would be appreciated

[SimonHobson]

Also during the good bit the downpipes were replaced so the lambda is no longer fitted but it didn't alter the running whatsoever (this normal)?
If it had a lambda probe fitted then it's a feedback signal - and you've removed it's feedback as to what the mixture is doing :rolleyes:

Different systems behave in different ways, and it also depends on how they've been set up. It may well just detect that the lambda probe isn't giving a signal and revert to open loop mode - in which case it will carry on running "about right" until something changes (like the air filter slowly increasing resistance and richening the mixture). Others will slowly adapt to what it thinks is a permanently weak mixture and slowly back off the fuelling - but it might take a while.

The answer is simple - refit the lambda probe, and you'll possibly have to re-program the unit.

[sharpy1980]

I will refit it but am wondering if it'll make any difference as it played up in the same way about a month before I removed it then it rectified itself after about 2 weeks, by rectified I mean it went for around a month without any running probs at all but is now back doing it constantly. Do these rough running problems sound normal to Lambda failure then? as I'm wondering if the Lambda I took out maybe duff.

Do you need special equipment to reprogram the system?

Just to add it looks as tho all the engine bay lpg stuff is Tartarini.

Thanks for your help:)

[SimonHobson]

I will refit it but am wondering if it'll make any difference as it played up in the same way about a month before I removed it then it rectified itself after about 2 weeks, by rectified I mean it went for around a month without any running probs at all but is now back doing it constantly. Do these rough running problems sound normal to Lambda failure then? as I'm wondering if the Lambda I took out maybe duff.
It's certainly possible that the probe is faulty - they do age, and they are easily damaged by a number of contaminants. If it's a zirconia one then it's easy to test if you have a small gas blowtorch handy :
connect a voltmeter to it's output
mount it gently in a vice (by the hexagonal bit of the body, you don't want to crush it)
stick the hot bit of the blowtorch on the tip
within a few seconds, the tip should be glowing red, and the voltmeter should read about 1V

Do you need special equipment to reprogram the system?

Just to add it looks as tho all the engine bay lpg stuff is Tartarini.
I'm not familiar with Tartarini, but usually you will need a serial cable specific to the system and some software (also specific to the system) - you hook up the cable between laptop and system, run the software, and usually there are pages for setting the options and viewing what is going on. There are various places that sell cables and software, and also places that provide it for download.


The thing is, hooking up the config/diagnostic software gives you a window into the system and what is going on - and normally tells you exactly what's wrong. Without it, you are just guessing.

[sharpy1980]

I had a quick look on Ebay and there are leads/software on there so I will check exactly what model it is to make sure I get the right one.
I will post when I know more:)