Where is my fuel?

IVA test today, so up at half past five to try to get to Norwich for 8. Unfortunately, we were held up by an accident on the way there, and ended up arriving around 8:30. I should mention that not only did it hail on the way there, it also snowed. This is not ideal in a car without a roof or windscreen. After I arrived, I had some coffee, and pretty soon I could feel my toes again.

The testers were very friendly and professional, and seemed genuinely interested in the car. When issues came up, they even spent some time phoning other stations to discuss details, so certainly a very fair appraisal.

Unfortunately, issues did indeed come up. Some trivial bits, and a few issues requiring a bit more effort to fix. No huge challenges or dangerous problems though, so that's something.

• Headlights and indicator positioning. Headlights too high and therefore obstructing drivers field of vision; indicators too far (by about 2 cm) from the outside edge of the vehicle. No two ways about it, the design of the headlight bar doesn't meet IVA requirements, although Peter thinks that his current design (unfortunately, I have an older design) should work.
• Steering column mount - at the point where the main column is mounted to the chassis, there is some flex in the mount, and the examiners indicated that they wanted to see some support for the mounting bracket. A bit of a judgement call this one, but no harm in beefing up the bracket a bit.
• Steering self-centering: there was none, and they obviously didn't feel (rightly, I think) that the springs on the rack were sufficient. Hopefully I can sort this out by fiddling with the geometry, but it's one of those things that I can't really test. Since they'd already reached a fail verdict by this point, we didn't try tweaking the toe settings. Oddly, there is loads of self-centering action in reverse, so if I can invert some aspect of the geometry, it should be good - this gives me some confidence that there is enough castor angle to get self-centering.
• Fuel tank strap, lack of. I used some supporting brackets to secure the tank, but they said they wanted to see either a full strap, or photos showing supporting brackets all around the tank, which isn't possible without removing panels - if I have to remove panels, I may as well add a full strap while I'm there.

Other details included a few non-radiused edges, but nothing very troubling. The use of this engine in the kit doesn't seem to present any particular problems - noise was 5 dB below the maximum (apparently that's a big margin, as these things go).

I got to find out the weight of the car, and was a bit disappointed to see that it's about 700 kg (no driver, nearly full fuel tank, full of oil etc). I reckon lighter wheels and battery will get me to about 650 kg; there's probably not much in the way of easy weight saving after that, or, to be honest, any real need for it...

On the positive side, they thought that the chassis looked good quality, and they seemed generally impressed by the way I'd put everything together, which was nice to hear.

Driving the car was good fun - now that I'm starting to get some confidence in the car, I gave it full beans a couple of times. It's very, very fast - the shift lights proved quite useful as there's not much time to look at the tach in the lower gears. Keeping up with the gear changes is fast work - it's really easy to accidentally get to the limiter in the first three gears. Given the amount of power I'm seeing, I think Jason is going to have some challenges dealing with 50% more again from the M3 motor...

Ergonomically, there's some work to be done. The huge steering wheel needs to go (after IVA, obviously); pedal layout needs improvement (less throttle travel); some kind of foot rest for the left foot, etc. There's very little space so this will be challenging - I don't think I'll get this to the level of the Elise, which has the advantage of not having to cram a gearbox between the occupants, so has much more space to play with.

My biggest concern is that it seems extremely thirsty, which is very worrying. It's probably not over-fueling (it passed emissions fine), so where is the fuel going? It's using probably twice as much fuel as it should, and I can't see it passing emissions or running properly if all of that was going into the engine. At a rough guess, it's getting about 10-15 mpg which doesn't seem right. A fuel leak is a scary scenario - I'll be going over the tank and fuel lines very, very carefully to eliminate this possibility.

Small steps to IVA

A few days ago, I sent off the forms for IVA. I've asked for Jan 24th, but I suspect they won't process my application in time for this, so it'll probably be after I get back from snowboarding (I get back mid-Feburary). The pressure, then, is now on to cross all the T's and dot the lower-case j's and get all the little details sorted for IVA.

As part of the final push for IVA readiness, I've prepared a long checklist. I spent the entire weekend from Friday through to Sunday working on it, and managed to tick off exactly one item (although admittedly the most time-consuming - the other will take less time, or the car won't be ready until 2012). I didn't realise that I needed grommets on the rear panel and wings to protect the wires to the rear lights, so had to retrofit them. Unfortunately, with the fuel tank in place, this is an unbelievable awkward task. I'll spare you the tedious details, but for the people just getting started with their builds, I would recommend getting the grommet in the first time.

I also took advantage of this to make sure the lights are totally level, and to replace the damaged driver's side wing. The lights are now lined up with the chassis to within about 0.1º, which should satisfy IVA people. Whilst putting in the new wing, I installed one of the wing protectors, and sadly got it wrong:

Wing protector not flush with the wing.

Due to the curvature of the wing, the protector needs to be installed flush against the chassis to avoid this gap. Consequently I had to drill out the rivets and move it over. It covers most of the holes from its original position, but not quite all, so I will have to fill the holes and paint over them. Very annoying and completely avoidable, but I think once I've covered it up it won't be noticeable.

MOT

This morning I set off in the cold and rain for an MOT. As expected, all the mechanical non-emissions stuff was absolutely fine; the only bit I couldn't be sure of passing was emissions.

The tester first tested it at idle. Some of the readings were OK, but hydrocarbons (unburnt fuel, I think) was  a bit on the high side - it started off at around 400, with 200 being a pass. CO was also high, hovering around 0.4 instead of under 0.2. We fiddled around for a while at different revs without much success - hydrocarbons dropped to around 220 but CO didn't really move much. He kept trying, and suddenly CO dropped to about 0.02, and hydrocarbons also dropped off to about 100 - so an overall MOT pass then.

I assume the delay is due to the lambda sensor that I didn't replace taking a long time to warm up. They're quite a bit further from the engine than they are on a normal 328, which can't help.

Next step: IVA.

More misfortune...

... although in fairness, I think I was the lucky one here. A while ago, I bought a power upgrade for the engine, consisting of a 325 inlet manifold with big bore throttle body, all of which will flow quite a bit more air to the engine. Apparently the 328 was artificially restricted with a less efficient inlet manifold to comply with German emissions regulations, and to increase the gap to the M3, so this should yield another 20 bhp or so. However, it didn't arrive, so I got in touch with the seller today.

Turns out, he was in a car crash just before Christmas, resulting in broken ribs and a written off car, which is currently in the hands of the insurance company, with my manifold in the boot :-(. Best wishes for a full recovery, if you're reading this Rob.

Apparently he's expecting to get the car back tomorrow, so hopefully the manifold won't be too badly delayed. Fingers crossed there won't be any more luck like this.

Wires

Today was mainly a day of wiring. At the MOT they weren't very happy with the routing of the wires to the rear wheel-speed sensors - possibly unfairly, I think, as they weren't going to go anywhere, and I think they would have been willing to let it go as an advisory, but I might as well sort it as the IVA people might take the same view. So I spent some time crawling around in the most awkward bit of the car to access (just by the diff), and eventually got them secured further away from the prop with no great difficulty.

Next I had a look at the fuel gauge and speedo. I'd thought that these were working OK, but they'd started intermittently failing, indicating, obviously, a loose wire somewhere. Since they share one of their wires going towards the back of the car, that's the obvious culprit, but some time with a multimeter revealed nothing. Eventually I gave Peter a quick ring, and he told me that he thought there might be a mistake on the wiring diagram, and suggested swapping the connections round on one of the dash plugs. Apparently the way I have it mostly works, but will randomly stop working, which is bizarre.

After a bit of fiddling, I found the right arrangement of wires, and now have a working fuel gauge and speedo (essential for IVA), which was all a lot more painless than I'd expected; I'd assumed I'd be crawling under the car for hours with a multimeter.

Spurred on by this success, I decided to try out my Christmas present - my parents kindly got me one of these for Christmas. Fitting was pretty simple: just wire up power, ground and tach signal. I've sited it behind the steering wheel so that it doesn't fail the IVA radius test - it's sufficiently bright that it's still nicely in peripheral vision here, and also nicely covers up a mistake I made when fitting the scuttle. Not sure it'll actually help cut my lap times but it certainly looks the part :-)

Shift lights startup sequence.

The car is now all ready for MOT - all the things they weren't happy with have been fixed, and everything is bolted back together again. I can't test the emissions, obviously, but there is less visible smoke/steam, which is a good sign.

Finally... progress

The problem with the richness looks to be solved. It was a problem with the lambdas, but not in the obvious way.

After spending a shocking £80 on a new lambda, I did some more testing on the old lambda sensors, and, after heating them up with a blowtorch, the faulty one came back to life. I ended up replacing it anyway, as this and other data suggest that it's on the way out. So, new lambda in place, I ran the engine and attached a multimeter to the lambda output, expecting to see it start to cycle between rich (close to 5v) and lean (closer to 0v), when the engine went into closed-loop mode. Unfortunately, this didn't happen: it stayed rock steady on about 4.8v (i.e., rich).

After much head-scratching, I plugged in the laptop, and noticed that the laptop was reporting 0v coming from the lambda sensors, even though they were outputting close to 5v. A quick scan of youtube (apparently, some people like to video their sessions of plugging a laptop into their car, and in this case I'm glad they do, although in general they should probably get some kind of hobby) yielded a video of someone running the same software on the same engine, which was clearly reading correct (non-zero) lambda sensor values: so the software is clearly capable of displaying correct values. A quick check of the wiring from the lambda sensor to the ECU showed that the wiring was OK, so the evidence pointed, improbably, towards an ECU which functioned fine in all respects except that it couldn't read the lambdas properly. If the ECU thought it was seeing 0v, then it would think that the fuel mix was too lean, and inject extra fuel to try and solve the problem... hence the emissions issues, and the numbers I was seeing from the lambdas.

The theory was promising, but I needed a new ECU to test it (number four, if you're counting - the first two had immobiliser issues, and the third had the lambda issue). This also meant a new immobiliser (they are paired with the ECU) and a matching key (again, the chip in the key is paired with the immobiliser). Fortunately, they are cheap on Ebay (about £50), but unfortunately most of the breakers who sell them are absolute cretins. Example email exchange:

Me: I need the ECU, immobiliser and keys - here is a picture to avoid confusion.
Cretin: Just to confirm, you just need the ecu and the key.

In the end, I found a seller who seemed to understand that I needed three items, not two, so I ordered it. Sadly, he turned out to be useless as well, and I didn't get it until four weeks later. He claimed he was snowed in (in Glasgow), but I'm not convinced the snow lasted for four weeks.

It was worth the wait though: I plugged in the new bits, swapped the chip in the key over and ran the engine. After a short warm-up, the lambdas started cycling nicely between rich and lean readings, suggesting that the engine is no longer running rich.

Assuming there's no snow on Saturday, it looks like I might get to MOT before Christmas after all, although I will probably freeze to death on the way there. I hope they don't object to the new ECU having reduced the milage by 60,000 miles.

Long overdue update

On the bright side, the seven continues to provide a rich learning experience, so to speak. The less cheery way of looking at it is, it still doesn't work, and in fact has even regressed in some ways.

After the failed MOT, much time was spent looking over the brakes and trying to figure out why they were seizing. The most significant factor turned out to be insufficient slack in the pedal: since the pedal (and hence the master cylinder) couldn't return fully, once pressurised, the system could never release fully, leaving the brakes dragging somewhat. As they dragged, temperatures rose (considerably), raising the pressure... which is why the car didn't make it to MOT without a rest; nothing to do with the handbrake, which was adjusted just fine.

A secondary factor, which Will and I spent quite a bit of time looking at, was the fact that even with this sorted, I still got about 3 ft-lbs of drag from each rear wheel. (For perspective, the diff on its own, being an LSD, takes about 7 ft-lbs to turn, which is just about turnable by hand using the discs, or not too hard to turn using the bigger radius of the wheels - so this roughly doubles the resistance at the rear). We tried winding back the pistons (no improvement); checking the callipers could slide freely on the pins (they could); checking the discs were central in the callipers (a washer was added on one side as a spacer to achieve this); with no improvement. Eventually I got the bench grinder out and ground the pads back by 1mm or so, trying not to inhale too much, and now they are fine.

Unfortunately a slight mishap occured while up on axle stands fixing the brakes: after everything was sorted, I started lowering the front of the car... and the rear fell off its axle stands. Happily, Emily's bike and Chris' lawnmower took most of the hit and absorbed a lot of the impact, but one rear wing of the car was damaged. It's an easy replace, but very, very annoying.

Brakes sorted and wing gaffer-taped up, I tightened up a couple of loose-ish unions that had leaked under the high pressure, topped up the fluid at the last minute, and had another go with Will following, and Becky looking nervous in the passenger seat. No issues getting there this time, but on arrival Will told me he was seeing big clouds of black smoke every time I put my foot down...

As half-expected, the engine indeed turned out to be running very rich. So rich that I hope the cat hasn't been destroyed - I don't think it's been run enough to seriously damage it, but we'll see; it was certainly another MOT fail (along with some a couple of loose nuts which will be trivial to sort out).

I've spent this week trying to figure out why the car is running so rich. I thought I had found the answer when I looked through the throttle body and saw this:

Oil in the inlet manifold.

But unfortunately, inspection of a friend's healthy 328 revealed the same thing, so I don't think this can be the issue. I've ordered a new CCV valve (the bit that's supposed to separate out the oil vapours before feeding back into the manifold) anyway, which I will fit anyway, as this is probably on its last legs at 100k miles (as indeed the state of the manifold suggests).

I had a bit of a poke around the fuel rail and discovered that all the injectors click at a sensible rate, so it's unlikely that one is stuck (and all the spark plugs are equally sooty anyway, so I don't think it will be a particular cylinder that has issues). Unfortunately I don't have anything suitable to measure fuel pressure, which, if too high, would explain things, but I will look into this.

Finally, last night, I had a bit of a breakthrough. After much research into lambda sensors, I removed mine, and tested them by heating with a blowtorch (which gets them to operating temperature - about 500º - and deprives them of oxygen since it's being consumed by the flame), and measured resistance as I did so (multimeter needs to be set to read at 200kΩ). Initially it should read infinity (lots of oxygen = lean conditions), then, when lacking oxygen (rich conditions), a finite value. One of mine just reads infinity, so it's always telling the ECU that there's not enough fuel...

Fingers crossed a replacement (£80!) will sort the engine out. I'm tempted to not bother and just wire up the working one so that the ECU reads it twice, but I suppose I might as well get it right. Also there's the possibility that the ECU fuels each group of three cylinders differently, as each one feeds its own lambda sensor.

This weekend's plan, then, is to replace the broken lambda, do a lot of tests to see if the engine is functioning properly, tighten up the loose nuts, and then the car should be in a fit state to pass MOT. Assuming, of course, that the cat is still OK - it will be expensive if it isn't.