Won't switch over - gloom and doom!

[JonC]

Hi Gilbert,

No, it's not that - I was measuring on the wires that go to the switch/gauge unit.

Anyway, just to try to make the best of things, I've relocated the Leo's own earth and it's now 0.1 ohms. So, there's the same voltage across the Leo inputs as I can read directly across the battery.

There's the same voltage measured between the Leo positives with the meter neg directly on the battery terminal. There's no additional resistance now.

Don't know if this helps - I get 12.02V (anywhere you care to check) with the ignition on but not running and 4.06V is the highest of the four switch connections. After starting, I've got 14.6V with the engine running - again, anywhere you like - but still 4.06V on hte samer switch wire. Wouldn't this suggest the Leo regulator is working?

There's nothing on the blue wire under any circumstances, it doesn't try to switch to gas and there's no change in the supply (measured at the Leo inputs) anywhere through the rev range.

It's as if it's switched to petrol or not seeing the rpm input (and that connection is good too!).

[Gilbertd]

Right, as I've never tested the voltages at the switch I've no idea what you should see but as there is a 5v regulator on the Leo board, I suspect what you are seeing is correct. Do you have the lead and software to see what the Leo is doing? I had a Leo sent to me to repair and all that was wrong with it was that the configuration file had been corrupted from a jump start and there was nothing actually wrong with it. All that was needed was a reset and reprogramme.

One thought, it may do something if you try the emergency start on gas setting. With the switch in the gas position turn on the ignition, this should give you a solid red light and a flashing yellow (indicating running on petrol but waiting to change over to gas). Without turning off the ignition then move the switch to petrol and back to gas again which should show a solid yellow light. Now, as soon as the Leo sees pulses on the brown wire it will output 12v on the blue wire to open the valves and allow you to start (or in the case of an Explorer, backfire into the inlet manifold blowing it to pieces) on gas. Do your lights work often enough for you to do this? I would also check the wire from the Leo to the switch, it may have chaffed through and be shorting out somewhere.

[rossko]

With the switch in the gas position turn on the ignition, this should give you a solid red light...

It's my understanding it falls down at that point, which suggests a hardware issue of some kind

[JonC]

Right gents,

As you switch the ignition on, you get ONE very brief flash from the red (petrol) light. After that, nothing frm any of them no matter what you do.

While driving, very occasionally you get the same, brief flash from the red.

[Gilbertd]

It still could be a poor connection (volts are there until the Leo tries to draw current) but it's now looking like a hardware problem. If you fancy a run to sunny Peterborough tomorrow, we could do a bit of swapping with your bits on my car and with my spare Leo system. Otherwise you could bung the bits in the post and I'll see what I find.

[JonC]

Once again that's a very kind offer and I think I have to say yes this time. It'll cost a few quid but then so will the next couple of weeks anyway and if I'm lucky I might get to drive back on gas!

Plus if I remember right, doin git on the car is the only way to keep all the config in place isn't it? It might be the first time it's ever been right!!

If you 'd like to pm me with some address and contact details, plus an idea of what time's good for you, we'll make it a date! I do have to be somewhere first thing but I'll be back by ten and it's about 1 3/4 hours according to Google.

Cheers!

[Gilbertd]

An update. Jon came over today and we set about sorting his problem.

First, tried to see if the computer would connect to his Leo and it wouldn't.
Checked both power supply and ground connections, all good (since Jon has sorted out the mess of spaghetti that is the wiring on this 'install').
Fitted my spare Leo and that wouldn't connect either.
Put his Leo on my car and the computer connected.
Saved the settings and loaded the config file for my car.
Started the car and it wouldn't switch over. Same symptom Jon had seen previously, turn on the ignition, petrol light flashes on briefly then goes dim. Gas light never comes on no matter what you do.
Checked the Leo with a magnifying glass for any obvious faults. Some slightly iffy soldered joints found so the iron came out and these were remade.
Tried it again on my car and no difference.
Cleaned up the pins in the programming plug on Jon's car and one of the data pins was so badly corroded that it fell out.
Replaced the missing data pin with a bit of paperclip and the computer connected with my spare Leo fitted.
Loaded my spare Leo with Jon's config file.
Started the car, revved the engine beyond the ridiculously high 2,100 rpm changeover speed set and it switched to gas.
Set the changeover revs to something sensible (1,400 rpm) and watched what it did on gas.
At both idle and normal running, the stepper tried to climb no matter how wide the limits were set suggesting that the vap needed a tweak to get it in the right region although the lambda wobbled around the 0.3-0.4v region so may not be as healthy as it could be.
Tried to find the vap.......

This install has to be seen to be believed. The front solenoid and filter is mounted inside the offside front wheelarch so can be accessed from the side if the wheels are turned to move it out of the way. The vap (an R90E) is mounted on the inside of the offside chassis rail but can only just be seen from above and below. It is mounted below the airbox and a relay box but almost totally inaccessible. Gave up at that point. It would run on gas so we left it like that. I've lent Jon my spare Leo for the time being until he gets a replacement and he went home wondering if it would be possible to get to the adjustment screws on the vap by removing the offside headlamp.

The first time I've seen an actual faulty Leo but as Jon left it with me, I may have another go at it and see if I can find the problem. But I have to say the install has literally been thrown in. The Leo was just stuffed up under the front bulkhead, the wiring loom hadn't been shortened at all but rather than the excess wires being neatly coiled up and taped or tie wrapped to keep them neat, had simply been stuffed in anywhere that they would fit. Both the locations of the filter and vap are unsuitable although I'm not sure where you could fit the vap on this car, there is so little space under the bonnet.