Thread: 3.9 EFI wont Idle on LPG

Originally Posted by 4range

Hi All,

It seems of late I am spending a lot of time asking for help with Range rover issues - this time it's the LPG system.

I have a 3.9 per the title. It is a duel fuel set up and a Landi Renzo system. the engine management system is EMS.

It recently began to idle roughly whilst on gas, then one evening on the way home from work, it decided to not idle on gas at all.

It actually seems to run fine on gas, so long as I dont stop for red lights & intersections - that's kinda frowned upon by my fellow road users!

Anyway, I have checked for leaks around all the various connections & not identified anything, & I have looked for breakdown of HT leads & not identified anything. (its not back firing).

Has anyone else suffered from this & / or have any pointers for diagnosis & rectification?

There are 1 or 2 idle mixture adjustments provided on the renzo landi converter. Find what looks like a knurled knob and try adjusting it a bit each way. If the idle improves you are going the right way. Idle mixture usually varies with a blocked air cleaner element, and often needs readjusting after a filter change.

Thanks,

I was wondering if my filter may have been choked, so after the car started stalling on Gas, I changed the filter - just this morning actually - I had expected that if this was the problem I might have seen some improvement after the filter change, without making any adjustments.

from the photo's, would you be able to tell which is the correct knob?

& please, no rude remarks about the the knob holding the camera!

Originally Posted by 4range

Thanks,

I was wondering if my filter may have been choked, so after the car started stalling on Gas, I changed the filter - just this morning actually - I had expected that if this was the problem I might have seen some improvement after the filter change, without making any adjustments.

from the photo's, would you be able to tell which is the correct knob?

& please, no rude remarks about the the knob holding the camera!

Both the knobs control the idle. The one hanging out the side (pic2) is the sensitivity. Adjust it out too far and it goes unstable. It needs to be just far enough out to get smooth progression from idle to mid revs. The other one (pic1) needs to be adjusted for correct flow.

However this is a converter I love to hate, they are very unstable. I only used to use them on engines in excess of 5 litres. Also the coil around the centre knob (pic1) is known to burn out, causing the problem you describe. Power it up and listen to the loud "clack" noise it makes. If not you need to either find a new coil or a new converter.

Attachment 36173

Hi try this attachment it gives you some more info on your system (same as mine) I found that it take a few ks for it to settle downafter each adjustment. I also found a mob in the U.K that does spare for them but cant find the web site, if I find it ill post it. Also you might find its a bit gummed up, mine was, if your brave enough take it apart and give it a clean up but it might then need setting up again depends how confident you are. (What say you bee-utey?)

Hope the attachment works im not the most computer literate person

MMEJ,

that is a great find.

I searched for that sort of thing for a couple of hours & found nothing like it!

Given that I am not much of a home mechanic, I have done some very basic things like change air filter & Plugs, drain the converter & check for vacuum leaks.

After Bee Utey provided the info on the knob's, I also gave them a twiddle, from 1/4 turn to 3/4 turns in either direction.

none of that made any obvious difference, so it is now booked in with an expert.

We will find out in due course what the problem is!

However, that attachment is gold to someone like me with only a speck of understanding of what the big round thing does!

I will be printing it off & keeping it with the worksop manual for future reference.

I won't be surprised if it ends up being an ignition problem. The couple of occasions I've had LPG issues on the Disco they've turned out to be the early stages of an ignition component failure.

Well, I dropped the Rangie off at the doctors yesterday.

No DIY solution for me I'm afraid!

The advice is that the converter has had it & requires replacing - that is the recomendation based on the age of the converter - 10 years old apparently.

Now I am waiting for a quote to supply & install a new one.

Whilst I am sure there is no difficulty involved in the physical installation, I figure that I may as well get the experts to install & tune it up at the same time instead of fiddling with something where I dont really know what I'm doing.

does any one have any ideas on what a reasonable price would be for a new converter?

Originally Posted by 4range

Well, I dropped the Rangie off at the doctors yesterday.

No DIY solution for me I'm afraid!

The advice is that the converter has had it & requires replacing - that is the recomendation based on the age of the converter - 10 years old apparently.

Now I am waiting for a quote to supply & install a new one.

Whilst I am sure there is no difficulty involved in the physical installation, I figure that I may as well get the experts to install & tune it up at the same time instead of fiddling with something where I dont really know what I'm doing.

does any one have any ideas on what a reasonable price would be for a new converter?

Age is of course irrelevant to the question. Heat related fatigue is what kills converter parts. 200,000 of regular travelling the Hay Plains is different to 200,000km of commuting. My wife had a converter on her car do 450,000km over 23 years and its still going.

You didn't report back that you had checked the valve on the front was working with a distinct "clack". This coil is a service part; I have replaced 10+ of these over the years.

Anyway, a converter trade price is around $220, with mark-up expect to pay $300 to $600 depending on the honesty of the workshop owner.