I don't think there's been mention yet of which vendor's C ECU it is, don't forget if it's a different make to your original one it will need that vendor's software (Zavoli / OMVL / Bigas / Etc sticker on ECU).

Yeh, would be good to read your results with the 7805.

When I read the stuff on calibration it always seems put over in a bit of an over-simplified fashion... will be because I know the iffs and buts and other stuff they've missed out or not explained properly ;-)

Nah, think more front garden with my mates, and going for midnight walks leaving the computer in the tent...But did used to carry a car battery when we went 'wild camping' (no tent) and slept by a fire in a field / bit of no mans land down next to a little river just a couple mile walk from home... Powered a CB, in case we could persuade anybody (females) to join us. Aerial was at least light and worked well, made a diipole using just wire and a loading coil bought from a ham specialist shop in Leeds, decent SWR too.

It's a Zavoli Alisei Simon, so no problems with integration/ software!
No doubt I'll be posting on here re the calibration, when I get to it. There is a 4wd rolling road dyno in Plymouth, but I think I should be able to get it close enough without going to those extremes...

Or just get the existing one fired up for long enough to save the settings from that and load them into the new one?

That would give a good base to start from, for sure.
Depends on whether I can keep the blue smoke in the jar when I attempt external power to the current one and whether the type B config files will transfer to the type C though.

Tried injecting 5V into various locations (on old ECU)- no joy. Too cold to mess around for long!

I would think that you would need to actually open up the ECU and trace where the voltage regulator is on the PCB and then apply the 5V to the output side of it (to do it properly)

I wouldn't have thought it would be too hard to find where it's located - it will be powered off the 12V pin somewhere, and probably have a couple of little smoothing capacitors near it.

You're right Marty. Opening the tin was the last resort though.
Now I've got a replacement ECU on the way, I can happily get the tin opener out and have a dig around inside. Also means I can work in the house, in the warm!

I don't think there'll be a problem loading B calibration file into C ECU. Calibration should be almost right, but if 5V issue has been causing incorrect pressure and temp readings calibration may need minor adjustments after the upload.

Simon

Well, I have to get it working first- can't get data out otherwise!
The 5V power supply is a:
http://uk.rs-online.com/web/p/low-dropout-voltage-regulators/5335610/
Only 500mA output current.

The 8 big resistors mid right look a bit heat damaged, but it could just be the sealant that the whole board's been sprayed with.

Lpgc wrote:

I don't think there'll be a problem loading B calibration file into C ECU. Calibration should be almost right, but if 5V issue has been causing incorrect pressure and temp readings calibration may need minor adjustments after the upload.

Board definitely looks heat damaged both under those resistors and in the vicinity of the large brown capacitor in centre-ish area. Tracing some of the circuitry back, I'm going for the brown capacitor hot area is the 12v solenoid switching area of the board.

Damage or just discolouration, though... Old boards that still work fine seem to get a bit discoloured in areas.

Reckon the big resistors are for petrol injector emulation?

Some of the other suffix boards are a different.design. Not related to your problems but since we're looking at a board might as well mention that if any of those little components at bottom left of top pic go wrong, you lose either peak or hold current to LPG injector(s). I dunno if some of those little 2 pin jobbies are diodes/resistors or what, but I do know that at least some ECUs use special diodes for timing peak.

Already mentioned I have an old broken OMVL ECU here (works OK on LPG but doesn't reconnect one of the petrol injectors when running on petrol).. I'm feeling semi inspired to have a look inside, see if there's anything obvious wrong. I will have a few other broken old ECUs laying around somewhere too..

Simon

Ref the big resistors, that's what I was thinking, based on the fact that there are 8 of them and they're a high power rating, which is what the engine ECU would expect to see where it was looking for injectors

Replacement ECU has arrived. It's a C, as I thought.
Wonder if it'll work...

Brown green brown, 150 Ohm? Although I believe each will be in series with a petrol injector while running on gas, resistor plus injector roughly 165 ohms. So say 14v battery voltage, series current of 85mA but voltage over the resistor would only be 12.7v.. At 12.7v and 85mA the resistor would dissipate 1.08watts. if resistor is rated at 1w resistor it's probably gonna get warm..

Obviously 165 Ohms is way different to petrol injector resistance (usually 13 to 16 Ohms)... Some petrol ECUs (not on P38s) notice this and interpret it as a disconnected petrol injector. so is necessary to address emulation resistance on some vehicles by fitting extra resistors in parallel with the LPG ECU emulation (about 40 Ohms usually does the trick). AEB124's are a neat way to do this, especially when using AEB2568 ECU's because they are a plug in solution (to injector break looms). Using AEB124's even where not necessary should take some heat off the ECU internal resistors.

Simon

No reason why it shouldn't work... if it's a good 'un and external wiring or component isn't the real issue!

A couple of these?
http://tinleytech.co.uk/shop/lpg-parts/aeb-124-for-sgis-n-inj-emulation/
I'll see how I get on with the new ECU first...

That's 'em, but I wouldn't bother on a vehicle that doesn't pick fault with petrol injector resistance either!

I keep some 124's on the shelf, and because I fit a wide range of ECUs not just AEB I sometimes have to cut the plugs off 124's to hardwire... An upshot of this is that I end up with some loose plugs, which can be wired to bypass a 2568 (and certain BRC ECU's) entirely for diagnostics where suspicion is that LPG ECU or ECU loom/plug doesn't reconnect petrol injectors but are difficult to access.

Just loading a clean version of 4.6.1 for a last- ditch effort to get calibration files off old ECU.
If fails, will just drop in new ECU, load v6 software and start from scratch

No signs of life from old ECU.
Setup from scratch on new ECU it is then. Plugged in new ECU. Switch lit up happily. Software v6.05 talks to ECU. Sees it as 8 cylinders.
Happy days
Now to read the setup manual...

Best to click 'reset the ECU', enter all basic settings, run auto-calibrate.

At this point calibration it should be roughly OK on a P38, but you should note actual pressure when running on LPG, repeat the above but this time enter that actual pressure as the reference pressure when entering basic settings.

Only now start to adjust the map manually.

This is because (1) you won't know the pressure supplied by the reducer while running on LPG until you've actually checked it while running on gas and (2) the shape (as opposed to just the values over the whole) of the map will have been adjusted from standard to suit the last vehicle the ECU was on, while auto-calibrate simply lifts or lowers all the numbers in the map by X%. For most people it will be easier to start from a clean slate regards map shape and default map shape isn't usually far out on a P38.

Simon