Bringing shame on all Seven owners

This week's progress has mostly been a mixture of sorting out interior panels, attempting to start the engine, and shaming all real Seven owners.

Firstly, the propshaft arrived and went in (actually I think this belongs in the last entry, but I forgot to mention it). Grease has been applied, bolts marked with a pen so I can see if they start to come loose, etc. I also obtained (finally) a short-shift gearstick from a Z3M and various (new) gear linkage bushes, with the result that the shift is now nice and precise, with a pretty short throw. The only downside is that to take the edge off the notchiness revealed by the short throw, I need a weighted gearstick knob. Since interior bling is the kind of thing that appeals to the more chavvy BMW owner, these tend to come with neon lights and a hefty price tag  (£70 for a secondhand gear knob!), both of which I would prefer to avoid. I'm still looking for a good one.

Now that I'm done with the transmission tunnel, and don't need further access to it, I've attached the panels behind the seats and around the tunnel - although I'd drilled the rivet holes, the panels still needed some adjustment - filing off rough edges, making the fit a little better, making holes for switches, and wires, etc.

Interior panels in place.

At the weekend, Nick (who formerly worked for an ECU tuning company) kindly came round and had a poke around the engine with a laptop attached. After several trips back and forth to fetch various bits, we got the laptop connected, and broke his kit car - one of the front wishbones snapped almost completely off. Fortunately it was bad enough that we noticed when we stopped, but not so bad that we crashed mid journey. Still, while it's off the road, it's probably a good excuse to drop an S2000 engine in it (it's currently got a Fiat 132 engine, which is a little lacking in poke). Shout if you need a hand with this, Nick.

The report we got out of the laptop was in German, sadly, but we managed to find the words EWS (if that's a word) and cam position sensor. We hooked up an oscilloscope to the cam sensor, and despite swapping it over for a new one, didn't get a convincing reading from either. It's not obvious what the problem is here.

The EWS is the immobiliser, which suggests that the engine seller wasn't very honest when he told me it didn't have one. This is a bit of a pain, as the ECU won't drive the coils without the presence of the immobiliser unit to which it's coded, which of course I don't have. Since most BMWs of this era (especially the more expensive models like the 328) would have had an immobiliser, I was concerned that it would be a huge pain trying to find a replacement ECU. Fortunately, I got lucky on Ebay and found an ECU from a manual 328 without immobiliser for £40 (usually they go for over £100). It's in the post.

The plan is to swap out the ECU and hope that solves the immobiliser issue. I'm not sure what the cam sensor issue is, but it shouldn't prevent engine start (I assume it will disable the VANOS dual cam system, but that's not critical).

Finally, in a move that will embarrass all proper, hardy Seven owners, I wired up the heated seats. It's against the no-frills tradition, but then again it's a car without a roof... I think they're probably a good idea. There's still a little wiring to be done, but they appear to be working.

slow progress

Not much in the way of visible progress since the last update, except that I am now a lot more familiar with the ignition wiring.

After putting some fuel in, the car wouldn't start. Closer investigation suggested that the fuel pump wasn't running - the cheapest and most likely candidate here was the relays, so after lots of faffing about with a multimeter, I got a couple of new relays off Ebay for £10 and tried again, with the same result. The relays seemed OK, so I took the fuel pump out and had a look. One of the terminals on the pump was burned, suggesting it had been damaged in the past, so I hit up Ebay again for a new pump... which didn't solve the problem.

The pump gets voltage for two seconds as soon as the key turns, to prime it, but then nothing more (at least this shows the pump wiring is good). Similarly, there's no spark, so, it seems that the ECU is unwilling to start the engine. Likely candidates are the crank position sensor (aka CPS) and the cam position sensor, so I replaced both of these (the former was a rather unpleasant £70). Unfortunately, this didn't help. The CPS is apparently responsible for reading engine revs, so it may not be a coincidence that I don't see any revs on the dash when cranking the engine - possibly the CPS wiring or mounting is dodgy. Speaking of the CPS mounting, it turns out that the previous owner managed to snap off the bolt securing the CPS, then attempted (badly) to drill it out, and finally gave up and used a cable tie:

Why do it properly when a cable tie will just about do?

After a long conversation with the international technical advisory board, one of whom is currently located somewhere in the Arctic Circle, we decided that we still suspect the CPS, with the immobiliser being the second most likely candidate (less likely because it cranks OK - I think if it had had an immobiliser, then the starter wouldn't run). More investigation tomorrow.

Fortunately, Jason provided some good news: his exhaust is ready and seems good, so mine shouldn't be long now. It looks very shiny:

Engine start (part 1)

Finished the wiring today and tried turning over the engine for the first time:

Everything appears to be working. It won't catch because there's no fuel, but I'll try it with the fuel tank tomorrow.

Very exciting... it's close to being a working car. If I put it in gear I can see the gearbox output shaft spinning.

Minor updates

Since the last post, not much has changed - not much time in the garage this weekend. However, I do have a new steering wheel, which I've trial fitted (it will need to come off for IVA). It's 320mm (the same as the Elise), which seems about right, possibly a little big. I'll see how it goes.

New steering wheel. Shiny.

The main progress has been with wiring. Emily has been busy attaching blade connectors to all the BMW plugs and wires, so the engine loom is now plugged into the main car loom. The ignition and steering column controls are not yet attached, but everything else (excluding lights, which aren't done yet) is.

Wiring in place.

The fuel filler cap has made progress this week. Last week, it was failing to line up (the filler cap protruded about 50mm from where the rear panel would go). After discussion with Peter, it sounds like my fuel tank has a longer nozzle than most, so I chopped that down, and trimmed the connecting hose to match. With that done, the filler appears to line up perfectly with the rear panel. While I was faffing around taking the fuel tank in and out, I also made some hefty brackets to stop the tank moving forwards, as it was just relying on being squeezed by some bits of chassis to stop it sliding around. I'll probably need to do the same to prevent any side-to-side movement as well.

Tonight I started trying to make a hole in the rear panel for the filler cap. This is turning out to be a massive hassle. Firstly, the adjustable hole saw that I bought specifically for this purpose turned out to be junk and fell apart after inscribing a rather imprecise circle on the panel. I went low-tech and drilled a ring of holes, then used the jigsaw to connect them. I then spent ages expanding the hole with a combination of:

• Tin-snips: couldn't get enough access to enlarge the hole cleanly.
• File: very, very slow going. And very noisy - the rear panel is basically acting like a big drum.
• Dremel: slow going.
• Angle grinder: the disc was too big to fit in the hole.
• Cursing a lot: this felt more helpful than it actually was.

It's currently still about 10mm too small. To be continued...