super4 wrote:
would appreciate some help. Have P38 Gems here on the mountain in Spain - LPG stopped working - just doesn't change on the button press - waits then beeps to make me press back to petrol. Have finally got the ECU lead from UK and downloaded Zavoli Alesei N software which loads and seems to work on my Win XP desktop (not connected to car) but does not run on my old laptop on Win 2000 . Says various dll files missing. Do you know if it should run or is Win XP the earliest ?
Chris B
You might need to reload the software from scratch so the dll files are installed, otherwise try copying them from the XP machine to the Win2000 and see if that works. Do you have an Alesei N or the earlier Alesei? They use different software and aren't compatible.
When you say it doesn't change on the button press, do you mean that ordinarily you switch to petrol before turning the engine off and leave it there until up to temperature? Why not leave it switched to gas so it switches when ready? The two main problems that stop a system from switching are a problem with the temperature sensor so the system thinks it isn't hot enough or a lack of gas pressure. If the temperature sensor has become disconnected so is open circuit, it will report -40 degrees so won't allow it to switch. If it beeps as it would when you run out of gas, then one of your solenoids could have died so the gas isn't getting through. Having a look around for anything disconnected and checking the solenoid coils would be a good place to start.
With a new software install, the Alisei software also has to be connected to the LPG ECU on the car, with ignition on before you can actually get/ set the correct configuration information. You'll find you have what appears to be a 3 cylinder car (amongst other things) with no option to change the config otherwise
Gilbertd wrote:
You might need to reload the software from scratch so the dll files are installed, otherwise try copying them from the XP machine to the Win2000 and see if that works. Do you have an Alesei N or the earlier Alesei? They use different software and aren't compatible.
When you say it doesn't change on the button press, do you mean that ordinarily you switch to petrol before turning the engine off and leave it there until up to temperature? Why not leave it switched to gas so it switches when ready? The two main problems that stop a system from switching are a problem with the temperature sensor so the system thinks it isn't hot enough or a lack of gas pressure. If the temperature sensor has become disconnected so is open circuit, it will report -40 degrees so won't allow it to switch. If it beeps as it would when you run out of gas, then one of your solenoids could have died so the gas isn't getting through. Having a look around for anything disconnected and checking the solenoid coils would be a good place to start.
You guys are great ! Really know your subject - well I loaded the Zavoli software (downloaded Alesei N from Tinley Tech) in slightly more up to date XP laptop and excitedly connected to P38 . Started engine, started programme and could see it all seemed to be reading things. Set gas button to Gas and waited for engine to warm - then saw that the changeover was for 1600 revs so increased speed and sure enough it changed to gas and stayed for 5- 10 mins. Thought perhaps just connecting software had solved problem but then as I increased the rpm I get a flashing red light on the button and software locks up. Reset button to petrol. Restarted software and found T.gas -60 and Press.gas n.a - all other readings were present as before but i don't know correct values. Have various ignition probs here in Spain which seem heat related although temp gauge stays in safe area. I took a series of 6 screen pics showing the stages and will try and add/upload but not sure how again. Chris in Spain up a mountain!
Have various ignition probs here in Spain which seem heat related although temp gauge stays in safe area.
Crankshaft position sensor?
gordonjcp wrote:
Have various ignition probs here in Spain which seem heat related although temp gauge stays in safe area.
Crankshaft position sensor?
Hi Gordon - could be right - and the rats have made a meal of my wiring but have always got it back to rights I think - meanwhile -could my diagnostic kit be any use to you ? I'm near Nerja/Torrox
Stupidly assumed you were in Spain too so last is irrelevant -but always willing to help !
Hi Gilbert D - just to say that I normally leave the button to keep on Gas but since I get the beep and flashing light as if running out of gas within a minute or two of starting I leave it selected on petrol. Needless to say there is 50 litres of gas in tank and unless a faulty batch don't think there is an obvious problem.
When it does it, check the reducer/vaporiser temperature. If there is a blockage or air lock in there as soon as it starts running on gas, the temperature will plummet and it will switch back. With the software running, you should be able to see the reducer temp anyway.
I have 6 screen shots of my LPG diagnostic which I hope can be seen.
Does this help any of you experts put your finger exactly on what is wrong ?
I see that on Photobucket they squash your pics down to 300 pixels so very hard to read the figures. I have changed to Imgur hoping it is better. Don't know about the order but they are numbered.
What Gilbert said. -60 no good for gas.
Hi Blueplastic - yes I noted that in his piece so does this mean that the temp sensor has failed for sure - is this the little thumb size temp sensor in the gas line just after the vaporizer or is there a temp sensor in vaporizer as well - if so how does one tell which is faulty ? Hard to get at wiring without cutting things as it is all in looms ! sorry to bother people ! I see the pics I uploaded to Photobucket are hard to enlarge and see the figures even though they are big when they left here !
I'm no expert mate so I couldn't help in that way. I'm just agreeing with Gilbert. I just know that the vapouriser get's heat solely from the circulated engine coolant and that if you had a blockage or air lock as Gilbert says, it'll turn off when you switch it to gas. Looking at the pictures, it is sensing the temperature to begin with so I wouldn't be sure it's a failed temperature sensor.
Are you allowing the car to fully get to temperature before attempting to switch to gas?
Is the coolant pipe going to the vapouriser hot?
Is the vapouriser hot?
When the gas temperature drops to -60 is the vapouriser hot?
When the gas temperature drops to -60 is the coolant pipe hot?
**edit.
Looking at the diagram, the sensor is the one you refer to that is screwed in.
Yes the Vaporiser is very hot and all the pipes around it - Everything under the bonnet here in Spain gets hot very quickly and the vaporisor is too hot to leave your hand on. Perhaps it is a solenoid on the vaporiser that is failing ? I must check the wiring to it but being a bit lazy I wanted an idea of where to start before cutting wires - these cars are so complicated - can't beat my old WW2 Willys jeep which I started with at 17 - well you could beat it with a hammer - all you need ed
Adding a engine pic - think I know now what most of the gas parts are - what about the pressure sensor on the right letter D ? Does that go wrong to cause this sort of pressure failure ?
http://imgur.com/a/cSSgA
The temperature sensor in the reducer is the one that gives the T Reduc figure at bottom left of the screen so that is showing everything fine up in the 70 degrees area. The one in the gas line gives the T Gas figure just above it and that is fine too. What isn't is the gas pressure. In Pic1, it's showing 1.38 bar, but in Pics 2 and 3, it has plummeted down to 0.73 and 0.46 bar. It appears that as the revs go up, the pressure drops and that is what will cause the system to switch back to petrol, it thinks you are running out of gas. Might be a clogged filter but it would need to be really clogged to have that amount of an effect, more likely one of the solenoids isn't opening properly. There's two, one on the tank and one on the reducer. Might be that a coil has gone partially short circuit or the plunger is sticking. Check the coil resistance (expect to see around 11-15 Ohms) plunger can be removed and cleaned on the reducer solenoid after you have slackened the feed pipe to allow the gas in the pipe from the tank to escape. Tank solenoid isn't so easy with a tank full of gas although you should have a manual shut off which will allow you to do the same.
The pressure sensor could be failing, there's two types, an AEB013 which is known for failing with age and the replacement, the AEB025 which is much more reliable and can be fitted as a replacement for the earlier one if you use an adapter cable. See the second row down on this page http://tinleytech.co.uk/product-category/lpg-parts/electrical/pressure-sensors/?widget_search=yes
Gosh - I'm impressed - such thorough info - I did check the solenoid on the tank before by putting 12 volts on it and it made a good sharp click every time. Now I'll check the one on the vaporiser - and the wiring to it because with the rats having had breakfast on the cabling one is never sure. And this problem started only when i pulled all the pipes and wires trying to change the back spark plug !!! I did renew the in-line filter about a year ago. Have to say that this LPG system has worked faultlessly for ten years and only stopped when I did the work on the plugs. Its hot working on cars outside here and the dirt track outside my house is not very good for under body work. Thank you for your help !
Sorry, I haven't contributed yet - been busy with other commitments and projects.
One thing that makes me wonder... is there a vacuum line from the manifold to the vapouriser?
I.maybbe way off the mark, but I would think that if this isn't connected, then you could end up with the vapouriser not increasing gas supply as it switches over, and especially under load...
I'll have a look at the pictures aswell, but seems like you have fairly sound advice so far :)
Yes - where else could one find so many experts on this particular topic ? Well, have given up for the day - hot out there and despite being pretty good at handling things cannot easily find a way to get at the two terminals on the vaporiser solenoid (keep forgetting the name) to test impedance or put 12 v down it. They are upside down and very hard to get at with the plug pulled. Traced the wires back to the big ECU plug so at least there is no break but found it shared a number of connections on there some with voltage on so didn't want to connect through that way. So if I take the solenoid off to clean plunger and check action where do I start ? Presumably the whole solenoid fitting bolted on to vapour thingy has to be undone and the pipe from the tank disconnected. Or can the solenoid just be undone with the nut that appears to hold it in place? All the pipes are as fitted and were working so if there is a vacuum problem it would be something I have broken or pulled. The car is drivable but because I'm stuck up a mountain I cannot risk having it off the road as eventually there will be a trip down to the post to get any spare parts that are needed. And the dogs have to be fed ! https://youtu.be/KiupuXv7P5k
Martyuk wrote:
One thing that makes me wonder... is there a vacuum line from the manifold to the vapouriser?
I.maybbe way off the mark, but I would think that if this isn't connected, then you could end up with the vapouriser not increasing gas supply as it switches over, and especially under load...
When I first took my car to Simon, it was idling like shite on gas. The vacuum line had been disconnected from the manifold and a blanking Tee put in. Not sure why as when Simon refitted it, it all worked well. However the pipe being disconnected didn't stop the Gas switching over in my case, just made it run awful. Worth checking though.