Chris's new build of an MX5 based car

[metal matt]

Up grade looking good there Chris. But I must ask, are you going to brave the colder weather to give it a test run and I have been tempted to upgrade my RAD to a nice shine alloy one.

https://www.flickr.com/photos/124541083@N02/

[CTWV50]

Originally Posted by metal matt

Up grade looking good there Chris. But I must ask, are you going to brave the colder weather to give it a test run and I have been tempted to upgrade my RAD to a nice shine alloy one.

https://www.flickr.com/photos/124541083@N02/

The last few post have been retrospective, I already have, and it's been quite warm and pleasant for September.

But I tell you what I nearly locked up the garage and let it be for 6 months when the wiring looked like this!!!

[CTWV50]

So I got it all sorted out. Wiring got a little bit much and I nearly made a possibly fatal error by wiring the B/W tacho wire to the B/W engine fuse wire, luckily I realised my error before connecting up the battery. Also mixed up the wires on my oil alarm so it went off as soon as you turned on the ignition. I'd wired it to the L/R ignition wire rather than the L/R fuel pump wire from the fuel pump relay. doh! Also my oil pressure gauge didn't work when I first turned it over. Couldn't figure out why but then I realised I'd earthed the body of the sender when I'd repositioned it. Ha! Soldered a wire to earth from the body of the sender which solved that issue.




It wouldn't start initially but it was struggling to turn over. I hooked up a 2nd battery and to my surprise it fired up about 9pm on a Saturday. Sounded terrible though due to the lack of oil in the hydraulic tappets. Turned it off a few times thinking I didn't have oil pressure but no, it was just sticking tappets. Let it warm up and then revved it a bit and it was fine.



I still had loads of wires to shorten but before I got stuck in I decided to look for error codes using the LED trick. This got quite interesting as I was getting three error codes, 11, 14, 22. Two of these didn't exist in the two digit error list which was confusing. I found someone else on the internet with the same three errors. 14 is an ecu internal barometric sensor error.

http://www.mazdamenders.net/index.ph...ult-codes.html



The dot/dash combination was -.-....--.. then a long pause. I knew that later cars had ODBII but this car had no OBDII port so assumed it was not OBDII.

Any how after a while I thought I'd look up some OBDII codes and discovered that a faulty coolant temp sensor should be P0115.

http://engine-codes.com/p0115_mazda.html

So then I pulled the rear green engine coolant sensor. I got the same previous error but also got another set of three digits

21,11,15 or --.-.-.....

so there was plenty of ones and fives in there but also these tens and a twenty. Eventually I figures out a dash - wasn't ten but was intact a separator so...

-- was two separators with no digit in the middle so that would be zero so I was actually getting -0-1-1-5 which was the correct code for the coolant temp sensor. I then looked up P1402 or -1-4-0-2 and found it was an erg issue.

http://engine-codes.com/p1402_mazda.html

I'd had the EGR device plugged into the loom to prevent any errors but it appeared removing the sensor from the alloy body had allowed the plunger to fully extend causing the error.

So 3 hours later I'd resolved the fault codes and could then carry on shortening the wires happy that all the wiring was OK.

What a palaver!

[SteveH1]

Nice build.
Where did you get the header tank from
Thanks
Stephen

[Rosco]

looks really neat! i love how clean it all looks!

[Ianr]

Its very interesting to see how your engine fitting compares with mine Chris. I don't know where you got the room for the battery where it is. As always brilliantly put together. Are you still using the same ECU or is it another for the 1.8 (I ask co I may be doing the same sometime)?

[CTWV50]

Originally Posted by SteveH1

Nice build.
Where did you get the header tank from
Thanks
Stephen

From a company called compbrake. Fairly expensive but clean and neat and of high quality. Any over pressure is dealt with by the cap which has an 8mm spout you can direct away from the electrics and engine bay. The polo one would just spit it out the back.

Originally Posted by Rosco

looks really neat! i love how clean it all looks!

Cheers, it's amazing what you can do when you have time on your hands. I did most of it whilst waiting for the DVLA. It's probably the cleanest engine I've ever had inside and out. I used simonz silver alloy wheel paint from halfards to paint most of the parts and a hightemp silver paint for the exhaust which seems to be holding up well.

Originally Posted by Ianr

Its very interesting to see how your engine fitting compares with mine Chris. I don't know where you got the room for the battery where it is. As always brilliantly put together. Are you still using the same ECU or is it another for the 1.8 (I ask co I may be doing the same sometime)?

No I had to wire in the 1.8 donors ECU, just a case of routing and shortening wires and trying to figure out which wires go to the back and to the fuse box. Every year of MX5 seems to be different and god know why they use same colour and stripe wires for different things like the engine fuse B/W and tach wire or the L/R ignition live but also fuel pump relay to pump wire. Took a week of every spare hour to get it all wired up neat.

The battery is a quality bike battery I think it's a varley redtop 20 or 25 I forget. Very compact and just there to start the engine really. It wasn't that expensive at the time but still a lot for a battery. Thanks for the compliments guys. Nice to know someones still reading my thread.

Sorry what am I saying!!! It's an Odyssey Extreme Racing 25 Battery - PC680 , I think i was just looking at the varleys at the time!! Doh!

[norton]

Has the lighter flywheel made it rev up more snappily?

[CTWV50]

Originally Posted by norton

Has the lighter flywheel made it rev up more snappily?

It's hard to say as I didn't drive this car with this engine without it but I can say that it feels more in balance with the weight of the car. When you come of the throttle there is definitely more engine braking due to the lower rotating mass. No downsides to it really. Initial off then line acceleration is more brutal and dramatic I'd say with this engine and in corners you can't just plant your foot down without some opposite lock action. Which makes the car more exciting to drive.

My friend was around at the weekend and we went for a quick blast. I asked his opinion on the speed of the thing and asked what it compared to. He's a car nut and has experience of lots of different cars and also works for Mazda. He described it as being a similar experience to, well here is the text.....,

"Trying to think of something to compare the off the mark acceleration to your car.
Came up with the time i was on the back of a Kawasaki gsr 1100.
; ) "

So although I judge the increase in speed and excitement as fairly mild compared to the previous engine. Others would say otherwise.

[norton]

A solid result then, well done!

But, what next...