leonardo AEB175 running problems

[scorpio1990]

Hey all. I was here a few months back with a shogun 3.0 v6 that wouldnt run on gas at all. Well i listened to your advice and checked the venturi ring and cleaned it up, i bought a new idle control valve, changed plugs and leads, swaped the stepper motor for a manual valve, bought a new lambda sensor, done oil change and new air filter and still lpg is having problems. She been on the road now for 4 days, first 2 days seemed to be running great on petrol and gas but i didnt really do much mileage, yesterday and today tho the lpg ran for about 10 minutes then went limp, felt like she was running on 3 cylinders, i stopped in a layby and switched to petrol and all went good again, i set off for home and tried gas again and went back to running on what feels like 3 cylinders so i disconnected a plug lead off the ignition coil and lpg came back to life, put plug lead back in and i set off again in lpg and after 4 mile went limp again. I went to my local lpg garage and filled tank just incase i was low (took £20 so was plenty in there) but no change. She is booked into a local garage for wednesday to have the lpg diagnostic done (did try buying one myself but my laptop recently died). But before she goes in i was hoping someone might have an idea what could be wrong?

Running a leonardo AEB175 controller, Romano evaporator/reducer, Pitagora 6/8 cylinder emulator

[Gilbertd]

Sounds more like a coolant flow problem meaning the vaporiser is starting to freeze. When it next does it, open the bonnet and try to put your hand on the vaporiser. It should be too hot to touch.

and take the manual valve out and put the stepper back, no point in having a Leo and lambda sensor if you aren't using them.

[scorpio1990]

hey buddy. Thanks for the reply. I have changed the manual valve back for the stepper motor as soon as i noticed it wasnt making a difference. As for the vaporiser, it's getting boiling, at one point i thought it was getting to hot as you cant keep your hand on it to long but been told its ok.

[scorpio1990]

I went out today and took off the valtek filter/solonoid. I checked the filter to make sure there was no crud in there and all seemed fine, filter aint new by all means but its not black (will get a new one now i know what i got). There was another solonoid on the vaporiser and i dont know what that controls, has a spring inside it with a slide bar, in the middle of the bar it has a hole with what looks like a flint in the middle?? anyway that had a bit of black gunk on it so cleaned it up, put it back together and took car for a spin. I didnt go far by all means but enough to get her warm, she didnt play up as much but for someone reason when holding at lights for about 20-30 seconds the revs drop and she changes to petrol and wont give me the option to go back to lpg unless i switch car off, take keys out of ignition and restart

[Gilbertd]

Eh? A Leo won't change to petrol, if no gas is getting through it will just die, the only way to make it change to petrol is by flicking the switch. What do you mean when you say it won't give you the option? The Leo will have a simple rocker switch, gas or petrol.

There will probably be a shut off on the vaporiser so that is what you have found, the spring loaded plunger shuts the flow of gas off when the power is removed from the coil. It needs to be clean.

[andy evans autogas]

In the Leo software on the diagnostic page you need to de-select / untick all the boxes. If they are selected then when a fault is logged eg: O2 sensor fault then the switch will give a slow bleep and return to petrol until power has been reinstated

[Gilbertd]

Will it? None of the 3 I've had do (or did). I actually use the slow flashing warning of lambda lean for too long, as an indication I'm running out of gas. I've got all diagnostics enabled too so if I check and find a stored error other than lambda lean for too long, I know I have another problem.

[andy evans autogas]

I was always under the impression that when they gave a slow flash that it has returned back to petrol ... But to be honest I never checked..... What about switching back with low fuel level ? I seem to remember that as an option.

[Gilbertd]

No, the slow flash just means it has logged an error but it carries on running on gas. As long as the error is no longer there after it has been restarted, the flashing stops but the error is logged in the software.

Switch back at low fuel level is the only option in the software that will cause it to switch back to petrol, but if that was the case it would need to see a low fuel level which wouldn't happen after being sat idling for 20-30 seconds.

[rossko]

Switch back will also occur at low RPM threshold, thinks its stalled - not sure if it can recover from that without switch off.

[Gilbertd]

That's true and if the settings aren't correct the Leo may think the engine is running slower than it really is. That coupled with too tight idle limits could allow the revs to drop a little and then it would cut back. I think we (Ross) may have sussed it.

It's the sort of problem you'd spot almost immediately if you've got a laptop hooked up to it but not by little snippets of information.

[scorpio1990]

I'm sorry if i caused confusion there. When i go out to the car in the morning and start her she is fine, switch to lpg and she is great, if i idle there for about 30 seconds the revs will just drop for no reason and almost cut out but she will switch to petrol automatically and saves herself from stalling, the lpg level lights on the rocker switch will go out and both lpg and petrol lights come on, i can move that switch as much as i want, rev her up to get her to switch to lpg as much as i want and she just wont do it UNLESS i switch the car off and restart and the process repeats.

I want to plug it into a laptop and see whats happening but i dont have a laptop anymore just my desktop pc, all my mates have laptops but dont have the required serial connection for lead i have. In about 20 minutes i am taking her to a local garage that has a guy there that used to work for a autogas company and he said he should be able to either fix it with settings or atleast tell me what is at fault so hopefully later i will be able to let you know whats gone wong

[rossko]

Shot in the dark - lambda wire came off when fitting new sensor, self learning is enabled and now its painted itself into a corner.

[Gilbertd]

Possible but my money is still on it thinking the revs are lower than they are by having the number of cylinders/coils set wrong. May well also have painted itself into a corner but that is the cause of the revs dropping in the first place, not the switching back to petrol and staying there.

[scorpio1990]

Hey guys. Right where do I start. You will prob understand this better than me but apparently it's not getting signal from the tps at low revs. The tps was tested and its fine and so is the wiring so he said the Leonardo controller is frazzled. He did mention about the lambda not swinging back and for as it should and the stepper motor is opening right up as if on full revs when its actually being held at 2500rpm. He also said the vaporizer is to small for the car but I can't see that, I know the previous owner and before she was parked up for 2 years the vaporizer was great. He quoted me 450 quid to get it working again lol

[Gilbertd]

He doesn't know what he's talking about then. Stepper opening right up means it's not got enough gas going through but it should stay at roughly the same opening all the time. All it does is fine tune the mixture, not control it, the vaporiser does that. Agreed, if it was too small for the engine it would run out of puff at high loads but you'd never achieve that just holding the throttle open with no load, it needs to be done when driving and flooring the throttle.

I've come across a couple of Leos that did strange things and responded to some changes but not others and the problem was cleared by going into the file management tab in the software and hitting the reset button. Then put all the config settings back in and it worked perfectly. Seems that can start to go senile with age but a restart sorts them out. Where in the country are you, I'll sort it for the same figure but with the zero knocked off the end.......

[scorpio1990]

I am in south Wales mate but happy to travel to someone who knows what they r talking about

[Gilbertd]

Don't know of anyone I'd trust with a Leo in South Wales. Ross is probably your closest on the other side of the water in Wiltshire.

[rossko]

I would think any of the pros on welsh side (rather than ex-pros) could sort that. Appreciate we are getting a secondhand story, but I think you need a second opinion here.

[scorpio1990]

I sat down on my pc tonight and read every single post with the words leonardo aeb175 in it and i been here for 4 hours lol. I can see the importance of the diagnostic tool now and if owning a leorando system you seriously need it, its now on top of my xmas list. I seen a few people having lpg drop out and it seems to be caused by bad/faulty electrics so thats my job tomorrow, alot of mention regarding the coil (brown) wire. I wanna look more into this fault i am supposed to be having with not having a signal from tps at idle, its a new (secondhand) tps that came with the throttle body so wondering if its knackered, also i noticed on my shogun the tps is adjustable by loosening screws and turning it, wondering if i set the tps below range causing the leo to think car is not running. Will get back to you tomorrow guys