Long time no update!
It’s been a while since I’ve updated this blog. The hot summer slowed me down and I spent time on other activities. That’s not to say that nothing happened but my enthusiasm for the build waned somewhat as little ‘issues’ kept cropping up which then took too long to resolve.
So here’s a list of things which were done since April. There maybe some overlap here but I can’t remember exactly what I did between April and today! And just to confuse things, the list starts from the most recent activity!!!
- Load MX5 NB 2003 Base Map into ME221 and get things running reasonably well.
- Modify clutch travel stop bolt to allow more travel.
- Trim end off clutch push rod.
- Fit air filter.
- Static engine timing / ECU crank pulse setting for smooth idle
- Complete expansion tank breather routing to radiator.
- O/S upper ball joint needs replacing, needs camber set.
- Buy IVA bonnet catches
- Tighten front brake unions, brake fluid in, bleed and check for leaks.
- Bleed clutch without pedal stop.
- PCV Breather filter
- Add clutch fluid
- Remove old FPR bracket
- Aim and tighten headlights, fit nut IVA boots
- Complete front light wiring
- Set front geometry.
- Side repeater into front wings and fit.
- Fit thin castle nuts to lower ball joints – may need washers.
- Fit front wheel arches.
- Torque rear hub nuts 275Nm
- Reset steering wheel.
- Edging around front wings
- Engine earth
- Fit IVA nut boots on rack
- Refit front Wilwood calipers and pads, torque to 40Nm?.
- Set FPR pressure without vacuum 57psi. For a healthy Mazda MX-5 NB Mk2.5 (1998–2005), the standard intake manifold vacuum at idle should typically be between 18 and 22 in-Hg when the engine is at full operating temperature.
- Complete fuel system
- Fit missing O ring on EGR flange
- Fit intercooler, inlet ducting. More on this later!
- Buy Green stuff front pads
- Fit front wing stays (needs thin castle nuts)
- Torque front hub nuts 200Nm
- Mount header tank and both hoses (fill and breather).
- Fit IAT
- Install throttle cable (shorten and modify plenum bracket)
- Fit battery wiring and battery
- Fit VIN plate
- Horn / clock modification / fit steering wheel.
- Tidy lambda
- Fit ECU vacuum hose
- Fit seats after adding edging U channel
- Side edging
- Fit centre tunnel cover
- Fit boot cover
- Rivnut and fit internal panels
- Fit dash board and switches etc.
Working through all of this took time, and many deliveries from various parts suppliers. Here are a few images:
Egg on face moment….
The time had come to get the engine running correctly after the extensive MX5 wiring cull, and the installation of a full return fuel system and adjustable Fuel Pressure Regulator (FPR). Time to program the ME221 appropriately. This is all new territory for me, so a steep learning curve.
An MX5 Mk2.5 normally aspirated base map was loaded into the ME221. Using the test functions I was able to check that the ECU / Engine loom wiring was correct. For example, from the MEITE software you can cycle each injector on and off once a second and hear it click. Similarly the VVT solenoid, the IACV and the cooling fan. You can also see the throttle position sensor working, the IAC and coolant temps, crank and camshaft position sensors. Once this was all checked(!?) an attempt was made to start the car. It did start but ran very poorly and wouldn’t idle at all. For a first attempt I considered this a result! However….
After fiddling about with the ME221 settings (and not paying too much attention to the manual) things deteriorated to a point where the car would run and then abruptly stop after three seconds. I decided to work on other parts of the build whilst I gave some thought to this problem….and read the manual.
After a couple of weeks I tried the car again and still the same (why wouldn’t it be!). I plugged in the laptop again and could see that the ME221 was cutting the spark after three seconds (no idea why). I then decided to reload the latest firmware into the ME221 along with a fresh MX5 Mk2.5 NA base map to start from a known good position. I then rechecked that the outputs of the ME221 were controlling things as it should. This was not the case – IACV and VVT solenoid control was swapped. Initially I thought this was my wiring (it still could be) but the connectors had the correct wire colours. Easy fix was to swap the ME221 outputs in the MEITE software. Turned the car over and hey ho it started and ran for 25 seconds or so before the revs dropped and the engine eventually stalled. More reading and realised that I needed to calibrate the TPS (throttle position sensor), an easy option in MEITE. Did this and the car started easier (as it now knew what the throttle positon was) and revving the engine was smoother. Unfortunately the engine still stalled after 25-30 seconds or so.
Time to raise a support ticket with Motorsport Electronics. Sent them log and config files and had an amended config back by the next day. Uploaded the new file and the car started and ran continuously – hurrah, but not the end of the story!
It had occured to me that installing the intercooler into the air intake system might impact the airflow into the engine when not used in conjunction with a turbo. Apparently intercoolers can drop 1-2 psi between input and output. This equates to a 10-20% drop in what a standard 1.8vvt engine expects (9psi vacuum at idle). Or maybe, as the intercooler is restricting the inlet airflow, the vacuum may have increased by 10-20%. Either way, it would seem that by installing the intercooler, I’ve been suffocating the engine somewhat.
So out came the intercooler and the ME221 map reverted to the standard base map. Well what do you know – engine runs perfectly (excepting the need for a full tuning map to be created).
I’ve chosen to view this episode as a learning opportunity combined with a quality escape. I will of course now change the intake plumbing to bypass the intercooler – if you’re wondering where that all went!!!
Here’s the remaining job list:
- Fit IVA bonnet catches
- Tidy engine loom routing
- Recheck all fuel connections under pressure.
- Balance wheels.
- Tighten rear brake unions, brake fluid in, bleed rear brakes and check for leaks.
- Fit front IVA nut covers
- Cover Battery box rivet covers in passenger footwell.
- Apply for IVA
- Wrap cat convertor / exhaust clamps??
- Fit bonnet and stripes
- Fit nose. Needs custom lower bracket
- Fit side stripes
- ECU tune
- MOT??
- Fit mirrors
