Eunos Chump

I've driven about 150 miles over the weekend, collecting data with Megatune and then using Megalog Viewer. I've used the VE analyzer function built into the latter, but frustratingly it kept wanting to make the entire map richer when it clearly didn't need it. Eventually I discovered the VE AFR Target field in Megatune (it's off by default with the MSPNP msq file), that was set for an AFR of 11.7 throughout. Once I'd changed that to more sensible values, things improved a great deal. It still has an uneven idle, but it runs very well in 'spirited' mode. Unfortunately it also shows the injectors are getting maxed out, so the 320cc ones will go in this week. I'm taking it to work tomorrow! Yes, I've got my AA membership card with me.

I set the timing yesterday, and today earthed the LC-1 wideband 02 sensor to the same spot as the Megasquirt - it's in the engine bay, beneath the washer bottle. I then reprogrammed the LC-1 output to wideband (by default, it emulates a narrowband), and I've now got what looks like a reliable AFR reading. The car was starting and idling well, so it was time for more gentle tuning... except the fuel tank was almost completely empty! What a muppet! There was little option but to drive it to the petrol station, about a mile away... and it was FINE. I then got Mrs B to drive it a little while I meddled with the fuelling, using the Required Fuel calculator mostly. It ran weak when set for a target AFR of 14.7, but using 12.7 (as recommended by DIYautotune) fixed that. Idle drops to 500rpm after a run though, it soon returns to 800 but I don't know why it does this yet. I took it for a longer gentle run this evening and collected some data, don't now what to make of th...

I f****** lives!!! It didn't start first time, it needed a little throttle but after 10 seconds idled on it's own. I let it warm up, and the idle came down to 900rpm, but it's not very smooth and the AFR reading is all over the place, I need to ground the LC-1 to the same point as the Megasquirt to get a reliable reading, apparently. Ignition advance looks a bit aggressive too. I didn't put the diode on the idle valve itself, I followed the advice in this thread and installed it within the MS - neat. I tapped the connection to the fuel pump relay as detailed here . The 'squirt had spent 24 hours in the airing cupboard before I started work. You need to clean the board once you've finished soldering, this involves using isopropyl alcohol first (buy a tin of PCB cleaner from Maplin, £3.50), then rinsing it in hot water . Yes, it does sound crazy, but it's true. You must remove the CPU first though! It's a version of the Motorola 68000 incidentally, a...

It was absolutely freaking awesome!

Installed the mods for fan and boost control this evening. Some of the connections comprise 2 component leads plus a wire, so they're not pretty joints. Plugged in the 'stim afterwards though and it does still seem to work. I made a hole in the case to mount the boost control transistor, there's no other space free. Now I'm working on understanding the wiring harness, I've got the fan on IAC2A, which comes out as pin 29 on the DB37 socket, and boost on IAC1B, pin 27. None of this matches the wiring diagram on miataturbo.net... oh, and the pre-built harness has the injector wires crossed, good job I tested that before fitting it. Won't be any progress tomorrow, going to see Star Trek. Monkeyboy is coming too, he assures me it's purely for the popcorn though. Soon he will love the Trek though, it is his destiny .

Well, I have missed my target installation date. I finished the base build yesterday, plugged in the 'stim, powered it up, LEDs started flashing... but not in anything like the correct order. It made me sad for a little while, but then I suspected the power supply was a little too weedy (9V 200ma), so dug out a 600ma one and it worked perfectly! My little face was smiling again! Next step was the ignition mods, you can see them in the picture below. Annoyingly, the 330 ohm resistors required don't come in the kit, and nor does the 0.1uf capacitor required. The whole lot only cost 64p from Maplin though. Note that once you've made these mods, the 'stim tests no longer work properly. This confused me, I thought something was wrong so reversed them, but it's correct - the 'stim can't simulate the CAS so you get no tach signal, hence no injectors. This is the point to install the required firmware. The system comes with the standard fuel-only firmware, you hav...

Getting close to completion now, I've reached step 73 in the manual but I think the tip of my soldering iron is finished. There are 2 very large resistors and diodes that needed more heat than it could manage, looks like a trip to Maplin in the morning. I've got all the software needed now, downloaded as a single package from DIYAutoTune. It has the MS1-Extra firmware needed to run ignition on an MX5, plus the tuning stuff (and it's all baffling). There's much to learn, but my goal is to at least try to start the car by the end of the weekend.

Not so much progress today, I was sidetracked by a user needing a password change (I'm on call this week), then got distracted by a bag of fruit pastilles and surfing the interweb. I did make a start on the outputs though, and spent some time being perplexed by section 65 in the MegaManual, where you need to make a choice on installing the high-current ignition driver parts. After much research, I found you skip this section and move on to step 66, only at the end do you make the ignition mods (using the pull-up resistors kit) for the MX5. A certain person has questioned my soldering skills - check it out below, Mr P! And this is something from my intersurf session, from B3ta :

This evening I built the input circuits, then tested with Megatune, and it's alive! The Megastim simulates the RPM (which flickers, this is normal apparently), coolant temp, TPS, O2, etc; you twiddle the knobs and it looks like you've got a running engine attached. The 2 switches on the stim select RPM range (low or high) and narrow or wideband O2 sensor (this is not mentioned in any of the instructions I have). I got some M2 & M3 nuts and bolts from Maplin, DIYAutoTune says there's no problem using them instead of nylon ones. They're sending me a replacement set, but it'll be a week before they arrive and I'd like to get it on the car this weekend.

Completed the comms part this evening, and had it talking to the PC. The MegaTune app only shows the DC voltage at the moment, it was very erratic but I'm putting that down to the power supply I'm using. I'm enjoying this so far, probably be a different story if it wasn't working though.

The Megasquirt was ready for collection on Thursday, and I only had to pay VAT and the Parcel Force fee, no import duty. I had Friday off (because I'm sick of work at the moment), so started off by building the Megastim (below). It's tricky stuff, if you've never soldered before this is not the place to start - the transistor sockets in particular are tiny. The online guide is very good though. I've spent much of the past 3 days eating at pubs, restaurants, and a big BBQ today, but I've spent some hours in the squirt lounge and the MS power supply is complete and tested now. Annoyingly, the plastic nuts (which secure the large transistors) are missing from my kit though. I've also bought a fancy racing hat for the upcoming track day at Bovington. I've never had one before so I had to go to the motor-bicycle showroom and try a load on. It seems I've got a funny shaped head but this one fitted perfectly, so despite being quite a bit more tha...

Breakfast Club again, this time it was Everything but the Car ... which meant lots and lots of motorbikes. Hundreds of them. Try as I might, I just can't get into bikes, I'm sure they're very quick but to me they either look like Harleys (lots of chintzy chrome), or race bikes (lots of chintzy carbon fibre). There was a big version of a Dragstar though, I did quite like that. There was also a helicopter, a removals truck, a Bedford Rascal camper, and a 1950s British Rail tractor thing, amongst other weird tat. I've been practicing my soldering, though my little LED torch didn't go well. I lost a component, which prompted me to set up a desk and chair in the garage, complete with geek lamp. I call it the 'Squirt Lounge . The 'Squirt arrived at my local sorting office on Saturday according to the parcel tracking website. So that's 4 days to get from Atlanta USA to Hampshire UK, yet the final 2 miles to my house has taken another 4 days... so far . Not i...

Eunos Chump will soon be coming to you from a digital computer ! This is a major step forward and will bring a host of new features, such as the phrase 'Mark is Ace' scrolling up the screen really fast (initially in monochrome but soon to feature random colour changes), and a text-based adventure game where you'll get to repeatedly see a round green door being drawn very slowly, before Gandalf cleaves your skull. You'll also be prompted to play a nice game of chess or tic-tac-toe, though if your name is Dave I'm afraid it won't be able to do that.