Engine is a 1.0 but has the Digiplex 2 ignition system fitted. (I have no idea why, the car is not standard at all but apparently had only the one previous owner & just a 'normal' user, not someone messing about with aftermarket anything - anytime I've driven with it where they lived, something weird always fails in my car suddenly, and that happened before I knew where they lived...)

Car been garaged for ages (long story, not by choice) & I kept it ticking over only way I'm allowed, by running it every so often.
(As I may have mentioned here previously, can't remember, I've had the car since 1995 or 6)

However I hadn't been keeping that up as frequently as I should have (another long story). Last time I started it it sounded a big chuggy, took a couple of tries to start it.

Yesterday it wouldn't start, I heard the injector come on (as it always does when the ignition is turned on) the first time - but the battery got progressively deader with each try, and the injector did not make its usual buzzy sound on subsequent tries.

So - got a battery charger, charged it back up. But now when I turn it on I get no injector sound.

The coil secondary resistance is low - 3.3 kOhms. Haynes say it should be 4.5 - 5000-ish kOhms.

but would that stop the injector coming on? The Haynes manual diagram shows the Digiplex 2 wiring connected to the ECU, so I am wondering if the lack of good secondary spark signal could prevent the injector coming on.

I have not checked to see if any fuel is getting to the injector yet, nor to the delivery pipe, hopefully try that tomorrow.
I did give it a few sprays (into the open butterfly) of an 'easy start' type spray, and that didn't help.

The fuel sender signal is fine & it's at battery volts (at the 2-pin connector at the tank unit), the fuel pump I'm not sure about - it has a 5v signal, and a 7 -8 volt (this is at the 3-pin connector, also at the tank unit). I have no idea what signals it ought to be getting.

The 2 4-pin plugs going to the SPI unit seem to be fine for continuity and volts signals - but again I have no data on what to expect at each connector, nor what each connector controls.

This is where it ceases to make sense, for me anyway -

when I unplug one of the 4-pin connectors to the SPI unit, the injector does buzz.
It also buzzes when I plug that 4-pin back into the SPI.

When I checked the connector going to that 4-pin - it made the injector buzz....which is like poltergeist sh*t, as if the signal jumped through the air...

I removed the coil, to dry it just in case it's damp as the car sadly is stuck in terrible conditions. When I tried to start it without the coil in, it makes the same sound (that dry chuggy highish pitched sound) as it does with the coil in.

? I'm not sure if the low secondary resistance could prevent the injector working correctly, surely not. But why does the injector buzz when the 4-pin connector is removed and plugged back in, and no longer when the ignition key is turned on.
(Hence suspicion whoever fitted the Digiplex 2 has wired the ignition signal via the coil etc in some way)

The ignition relay has battery volts, the fuel pump relay has sensor level volts though (~ 5v) - I have no idea what it ought to be getting.
The relays and their respective fuses both show up ok.



Does anyone know why these SPI units are so scarce? I've seen one for sale - reconditioned - in like 5 years. And one other recently but it's only part of the unit.

I don't fancy having to convert to a carb just cause of the extra everything I'd need to change, I have nowhere to work on it. Pump change, fuel lines, mounting brackets, throttle cable alterations....it'd be nice to be able to do stuff like that, but I have f.a.
(Can't move it as there's a big slope right behind it to a mega-skinny driveway, so can't even roll it back and forth for access - my knees are killing me from squeezing in at the engine bay as it is)

Also, while I am asking about this, regarding replacement ECUs - there seem to be lots of versions of them. In terms of the serial numbers. Do they all do the same thing, are interchangable?

eg mine is (on the ECU these numbers are from) -

0280 000 710
265.15
28SA2095
172 0000 664

I see there's various ECUs all for 1.0 and 1.1 Unos with SPI - do they all work the same way? Expect the same sensor signals and output the same to the injector?

What about SPI injector units for the larger engined Unos - would they fit in the same manifold as the 1.0 ?
(not sure how viable that option is anyway, would mean sticking an extra resistor into the control voltage wire/s, so it reduces the opening time - and it wouldn't be scaled so likely would overfuel at various settings - if it even uses volt-amp amounts to control the pulse width)

Another thing about the matching of ECUs to injection units and ignition systems - the original breakerless (and possibly other digital ignition systems used) system which would have been on the 1.0 and 1.1 - doesn't take an ignition input, it decided on the fuelling without that.

So which ECUs for the Monojetronic are the ones that do take the ignition input?!

It seems there is no way to find out this kind of info, unless you happen to have various examples of the vehicles to hand all in running order.

(My experience of trying to query manufacturers is that - nobody knows anything there either, or they just don't even reply. Most of the shops don't know anything either of course, unless they are specialist then there's a chance they do.)

Where the fook did my reply go, I spent a while typing that in - and some **** just deleted it.

Tonnes of relevant info in there - real life stuff and important, the truth is what ****ing matters ffs.

If easystart did nothing it would suggest you have no spark, or, that its massively flooded.