PRINS installation - won't attempt to switch to LPG

[pete10]

Hi, Many moons ago i paid for a professional install of my prins vsi system, this was onto a Fiat. I then transplanted the system myself onto a rover, all went well. I've now transplanted the system back onto another Fiat (not the same car as original btw!).

I had no problems at all fitting the system onto the Rover however following completion of the install onto the fiat i've encountered the following problem:-

When i first attempted to test the system it seemed to be dead, no lights at all on the fuel switch. I traced the inital problem to not the main fuse but one of the secondard fuses which i believe are for the injectors. My system has 2 additional fuses 10amp and 2 amp it was the 2 amp that had blown.

I replaced the fuse and the system was alive! or so i thought .... once warm (evaporator is definitely getting good heat, easy to feel) the system did not attempt to switch over. The fuel switch shows a solid orange light which is on constantly until the ignition is switched off.

After several attempts i have noticed that the system initially starts with a dim orange light. If you press the fuel switch it gives 2 beeps and the orange light gets brighter, but still does not switch to LPG (no selenoid click), if you press it again it gives a single beep and the orange light dims, but remains constant with no switch over attempt.

I've checked all plugs and wiring and can't see any obvious problems altough i've yet to go over it in daylight. Can anyone suggest which areas i should check first ? is it possible to check of the system is trying to trip the selenoid for instance ?

The tank is showing some fuel on the tank gauge, but has been sitting in the back of the garage for a good 6 months...

Thanks in advance !

[rossko]

Remove fuses before install, cos its easy to blow them with dangly wires everywhere.

Dim orange - I am in petrol mode and will stay that way

Bright orange - I am in gas mode but waiting for things before changing over. For RPM; for vaporiser temperature; for a delay to expire (length of which which can be changed in software).

errm, have you ever set this up when swapping it about?

[pete10]

Remove fuses before install, cos its easy to blow them with dangly wires everywhere.

Dim orange - I am in petrol mode and will stay that way

Bright orange - I am in gas mode but waiting for things before changing over. For RPM; for vaporiser temperature; for a delay to expire (length of which which can be changed in software).

errm, have you ever set this up when swapping it about?

Thanks for the quick reply rossko - when i switched the kit to the rover i had fully expected to have to take it somewhere for set up but it worked perfectly when i tested it, and continued to do so the config remained as it was originally set up.

Could the system show these symptoms if it lacked the RPM signal ? i.e. default mode of dim orange, then bright orange only when you press the fuel swith. You read my other post where i mentioned there are 3 wires to each coil - 1 red, 1 black, and 1 multi colour different on each coil. I used the multi coloured wire from the coil closest to the gearbox end of the engine, perhaps this is incorrect. is there any way i can check that this is giving the required pulse ? can this be seen by using a test bulb for instance ? i only have a simple voltmeter which i presume will not register the pulse.

I'd like to rule out any basic problems if possible before i take it somewhere to be checked if it needs it....

[Gilbertd]

Plug your computer into it and see if it is showing any rpm readings. If you don't have the software, you can't see what it is doing so you are going on pure guesswork.

[pete10]

Plug your computer into it and see if it is showing any rpm readings. If you don't have the software, you can't see what it is doing so you are going on pure guesswork.

I had just seen that the iterface kit is available on the internet now with "VSI diagnostics D2.2" and "VSI diagnostics v 2.5.1" for a reasonable price, assume this is the correct software to show error codes, sensor readings, etc ? if so i'll give it a go

[pete10]

Also, forgot to ask, i haven't hooked up the filler pipe yet but i don't think this has any effect does it (other then not being able to add any new gas to the tank yet of course )

[Gilbertd]

I had just seen that the iterface kit is available on the internet now with "VSI diagnostics D2.2" and "VSI diagnostics v 2.5.1" for a reasonable price, assume this is the correct software to show error codes, sensor readings, etc ? if so i'll give it a go

I don't know as I don't have a Prins system or the software but I'm sure someone that does will tell you what version will work.

[Gilbertd]

Also, forgot to ask, i haven't hooked up the filler pipe yet but i don't think this has any effect does it (other then not being able to add any new gas to the tank yet of course :) )

It will if the tank is empty. It never will change over then......

[jalfrezigazee]

not sure which version of software you need, I bought V2.4.5 and this works on my 5 year old VSI system and my newer VSI system with the turbo mapping hardware. Bet you they will both work

[jalfrezigazee]

Also, forgot to ask, i haven't hooked up the filler pipe yet but i don't think this has any effect does it (other then not being able to add any new gas to the tank yet of course )

It will if the tank is empty. It never will change over then......

I think the fella means he has some gas in the tank. If it was detecting the low pressure then the bright orange light would go back to dull and it would beep loudly telling you it is out of fuel

Many things could be the issue, maybe it is not getting a temp reading so it is still waiting to warm up

[Gilbertd]

I'm going to get into the habit of using smileys when I post tongue in cheek replies. I suspect he does know enough about what he's doing to make sure it has gas in it, but you never know.....

[pete10]

i'm confused now .... will it run on an empty tank of won't it

In advance of getting hold of the software/lead I've tried to check the pickup for the RPM from the coil as it's the factor which i'm least sure about when it comes to re-wiring the system.

The wire i've used for the RPM (the third wire which is a different colour on each cylinder, orange in the case of the right most cylinder) gives no reading at all on a voltmeter (engine started or not). Should it read 12v when the engine is started ?
When i bridge it to ground with a test bulb in line the engine sounds like it drops to 3 cylinders, does this confirm that i'm interrupting the current to signal the spark and therefore i'm using the correct wire to read the RPM ?

[jalfrezigazee]

the experts can correct me but I would be quite confident in saying that if you do not have enough fuel in the tank then the system will never switch over. When the solenoids switch over and the low pressure is detected the system will auto switch straight back to petrol.

I dont think this is the problem though as you said the orange light stays bright all the time. You have at least 1 signal not being registered

Sorry don't know about the other stuff though

[Gilbertd]

i'm confused now .... will it run on an empty tank of won't it :wink:

Errm, no. No gas, no gas pressure, no changeover.

When i bridge it to ground with a test bulb in line the engine sounds like it drops to 3 cylinders, does this confirm that i'm interrupting the current to signal the spark and therefore i'm using the correct wire to read the RPM ?

Sounds like you've got the right one then. When the engine is running it will have short pulses of earth/ground on it. Each pulse equals a spark. If you ground it then there's no sparks so it will stop running on the corresponding cylinder.

[pete10]

Errm, no. No gas, no gas pressure, no changeover.

Sorry, i was only kidding - it is registering something like 1/6 tank on the needle gauge attached to the tank, and i could feel it sloshing about when i fitted the tank. I will stick some more in when i get the filler fitted just to make certain it's not a lack of gas pressure from tank.

When i bridge it to ground with a test bulb in line the engine sounds like it drops to 3 cylinders, does this confirm that i'm interrupting the current to signal the spark and therefore i'm using the correct wire to read the RPM ?

Sounds like you've got the right one then. When the engine is running it will have short pulses of earth/ground on it. Each pulse equals a spark. If you ground it then there's no sparks so it will stop running on the corresponding cylinder.[/quote]

That sounds hopeful in that i've got the correct RPM signal then thanks for the info.

I guess i'll be waiting until the dignostic cable turns up before i can try and make progress with the problem

[rossko]

If you just had an empty tank, the system would attempt changeover before discovering the lack of pressure, it would either stall or fail back to petrol with bleeping.

Using your meter on an AC volts range on your coloured wire may show some small voltage from the trigger pulses. Putting a bulb on that wire would short the pulses out and kill that cylinder temporarily, which is what you describe.

The Prins software needs to be told the kind of RPM pulses to expect, its really a remarkable chance that you swapped this between cars before without running into an issue like this.

[pete10]

The Prins software needs to be told the kind of RPM pulses to expect, its really a remarkable chance that you swapped this between cars before without running into an issue like this.

I completely agree, i think i was very lucky with the first swap. The irony is i swapped if off a Fiat onto an Rover MG, with no tweaking required, and now i've switched it back to a Fiat and hit a problem ....

[pete10]

Hello all, finally got round to this. Using VSI Diagnostics D2.5.1 it looks as if it is the RPM signal which is the problem ? The 5th variable which shows RPM shows a reading of zero and in the sensors tab in the bottom right corner the RPM_Flank reading is showing as 'Failure'.

I've attached the screen shot - please can anyone confirm if my thought is correct and i should look to sort out the RPM signal in order to at least get the thing attempting to trip to LPG ?



Uploaded with ImageShack.us

[rossko]

...in the sensors tab in the bottom right corner the RPM_Flank reading is showing as 'Failure'.

I think that's saying there is a failure to make sense of the flank parameter setting, rather than detecting a problem with the input. I expect it got corrupt somewhere along the way.
Try setting it to zero, this forces an idiot mode where no input = stopped, any input = running.
If that works, you can set it back to something more meaningful.

[pete10]

I think that's saying there is a failure to make sense of the flank parameter setting, rather than detecting a problem with the input. I expect it got corrupt somewhere along the way.
Try setting it to zero, this forces an idiot mode where no input = stopped, any input = running.
If that works, you can set it back to something more meaningful.

Thanks for the reply Rossko.

I had a play today and I noticed when i first started the car and began to try various different voltage setting for the RPM input (by changing the L_type setting) i got a couple of very erratic RPM readings, none were stable (darted around dramatically) and nothing comparable to the tick over RPM which the car was sitting at. The RPM reading then stopped all together, and i couldn't get a reading at all using any of the L_type settings inc the zero setting.

I guess i should re-check the purple/white RPM wire, seems odd that i got an erratic reading to begin with and then dead...

Any pointers appreciated!