Engine Started!

The problem of the stalling engine turned out to be fairly obvious; there is an air outlet at the back of the intake manifold that feeds the assisted brakes on the MX5. There is no equivalent on the Westfield, so this outlet needed to be blocked off. I'd overlooked it in my eagerness to get the engine running.

With that blocked off, the engine fired up easily coz air was being fed into the injectors and cylinders rather than widdling out into the engine bay. Sounds very much more imposing than it ought to due to the lack of exhaust pipe and silencer at the moment.

It is still not a complete success, the oil pressure is reading worryingly low; around 10-15 pounds per square inch (around 1 bar). It ought to be approaching 40 psi, and I don't fancy running the engine at under that - if that is in fact an accurate reading.

And the coolant fan from the MX5 doesn't work - it really had experienced an overheating problem at some point in the past.

The causes of low oil pressure could be an oil leak (which doesn't appear to be the case - exhaust is too clean, no puddles under the car, and coolant is still clear), a faulty pressure sensor, or possibly the oil filter causing a bottleneck (I had put on an OEM rather than Mazda filter), otherwise it is either a blockage or oil pump problem within the engine. If it is a blockage or the oil pump is knackered, it's bad news - the engine will have to come out and be taken to pieces in a fairly major way. Ugh.

I'll start off replacing the oil filter and pressure sensor - this still requires a slight disassembly due to the restricted space in the Westfield engine bay. And I'll have to replace the fan motor of course.

And there is still the flaky left hand indicator - I'm beginning to suspect the relay rather than the wiring, but investigations continue apace.

Wibbly Progress

Slow and wibbly progress...

The scuttle has been completed, with the windscreen, wiper boxes and motor, and the wing mirrors all installed. It was one of the more labour-intensive body panels, so I'm glad it is out of the way. Getting the rake of the windscreen and distance from the rear datum correct took a bit of patient fiddling.

Then that was followed by a bit more wiring fun (there is *always* wiring fun!)

Popping the scuttle on, and the dashboard temporarily in place followed, along with the headlights, rear lights, and side indicators. The side indicators were a bit of a pain - exacting and complex holes were required to be cut for them.

The header tank was the next thing, completing the cooling system. I think I've mounted it a little low but it is still above the entire system so it ought to be OK.

And then it was time for a trial start-up! With an audience of course.

Who were inevitably disappointed.

Nothing happened at all - the secondary circuits for lights and instrumentation worked (after a fashion - one of the indicators was under the mistaken impression that it was a headlamp). But the primary circuits for the ECU, fuel pump, and ignition coil are as dead as a very dead thing indeed. The wiring diagrams had to come out yet again - but it became clear pretty rapidly that an instant fix wasn't going to happen.

Some amusement was provided by me accidentally triggering the horns that without a bonnet on and in the enclosed garage caused us all to jump in the air in shock.


Since then I've removed the scuttle and set about the wiring with the manuals, multimeter, and home-made diagnostic tool.

So far I've discovered a duff ground that I had done which I corrected, a duff ground that was due to corrosion on one of the MX5 common earth connectors which I replaced. Sorting these has corrected the side-indicator problem, the ECU is communicating correctly and not reporting any errors, and the engine turns over. It doesn't yet idle and always stalls however.

I think (hope) that this is just down to timing settings, but it is possible that a problem still exists in the wiring somewhere. For example, I found out that one of the wires that I removed is required (the neutral/clutch switch wire) - I don't think that it should prevent the engine starting though. To rule that out in any case, I've fashioned a temporary replacement.

It's easy to think that if I were to do it again that I wouldn't cut out the wires from the loom that are not required. But it would have just annoyed me knowing that they were in there.