Did some tweaking to the car such as tidying up the wiring under the bonnet and tap out the transmission tunnel where the propshaft UJ was rubbing and then took it out for its first proper test drive. Boy does it shift! The MX5 seats have made a huge difference to the way the car feels too. Everything feels more complete and secure. I think I’m going to enjoy this!
Sadly the test drive threw up some more items for the snagging list. The handbrake needed adjusting, the speedo cable snapped, the brakes needed another bleed and the temperature gauge wasn’t working. The gauge was a simple case of the wire being disconnected I hope, I can’t test it properly as the car hasn’t got any water in it right now. All the sensors have the correct resistances and the fan operates when it should so it’s not any major worry. Quick heads up for anyone with the RAC MX5 Mk1 book, ignore its section on the temperature gauge sensor as it’s completely wrong and the sensor it refers to is for the engine fan.
Checking the speedo cable revealed it had snapped on the section I was worried about – not making a gearbox tunnel yet was a wise idea. The speedo gear housing in the gearbox has now been shortened as has the key on the end of the cable which goes into it. Actually a completely new one was made! Photos later.
When it came to bleeding the brakes I noticed the differential sounded a little unhappy. I had concerns over the diff as with the old Cherrybomb on there I couldn’t, hear what state it was in. If it was slowly dying a noisey death I’d never know until it fully expired. Almost doubling the power going through it made a little voice in the back of my head louder. I umm’d and err’d for a while then bit to bullet and removed it. When I topped it up with oil three weeks ago it was almost empty and straight away nice clean oil leaks out. This said two things at the time – it had no oil in it and it was very leaky! I already had new shaft seals for it so to make it safe I though it best to whip it out, do an inspection and replace the seals. Less than mouthful of oil came out when it was removed! The video below has the noise in it.
On strip down the thrust washers were found to be worn. Another interesting thing thrown up – the ones the manual tells you to measure aren’t available in different sizes, they’re also made out of copper and not bronze and the ones you can buy in different sizes are all out of stock. Simple, make some then!
Whilst that was happening a pinion seal, gasket and new Polybushes for the rear were bought and then it was thrown back together after a drain had been tapped and drilled.
Yes, it’s all white. The reasoning for it is that it’ll show up leaks far more easily than a black one, I had lots of white paint kicking around and it’ll add 15bhp at the wheels. One thing I did notice when putting it all back together was how much of a difference the new bushes have made. Getting the spring back in with a 1″ lowering block was a nightmare. Normally I can do it on my own quickly, but this was a right faff as the diff is now sitting at least a 1/4″ higher – the old bushes were that badly worn. Also means the car will be that much lower now, which is good.
Not been doing too much to the car this last week but small steps forwards were made over the last couple of days. Mostly heater related. Being an ignorant person whilst also wanting to make sure I used as many standard parts as possible to make replacement due to failure easier I was insistent on using the original Herald heater valve. For those not in the know, it sits on the outside of the heater box which lives in the engine bay. It attaches to that by having a rubber olive seal directly onto the pipe of the heater matrix and the unit is bolted to the heater box so it’s secure enough to be cable operated. I couldn’t use the original any more as the engine is where the heater was, so I’ve used a mk4/1500 Spitfire heater box inside the car. And I couldn’t mount it directly onto the pipes of the heater matrix as one pull on the cable to adjust temperature would bend it all. So, one block of aluminium later there was a solution!
Those with a good memory will remember I was going to use a mk3 heater. I’ve swapped for a later one as it’s slightly faster. I’ve bypassed the resistor and now it’ll run at full speed rather than having two settings. I have no need for a slow fan. If I want less warmth I’ll turn it down with the heater valve. I only really want it for screen demisting anyway as I’ve not had a working heater for some time now and I’m used to it. I’ve also not cut any extra holes in the bulkhead for its inlet. Instead I’ve spaced it from the bulkhead so it’ll constantly be re-circulating cabin air. This may see the windows getting mistier as it heats moist air, it may not. It’ll certainly make bottom burps more potent.
I’ve also had a problem with a leaking fuel tank which after a bit of faffing was solved. But that lead to me spotting injector number four was leaking. After a bit of research I discovered that Mazda changed the insulator between the injector and inlet manifold early in the MX5 production. What I had fitted to my car was the early (and probably never touched before) one which didn’t like to be disturbed which I’ve obviously had to do to paint the manifold. The new ones were also used on mk2 MX5’s and will happily be removed and messed around with numerous times before they begin to leak. Turns out these new insulators aren’t very cheap either, well, I consider £20 for four little bits of rubber coated plastic to be expensive! So I bought an injector seal kit for the same price and set to it. Very quick and easy as it turns out, but then that could be in part to me being careful and thinking out a few things last time I reassembled everything with the intention of making strip down quick and easy!
So now it was time to fill the car up with water and discover my cock-up. I’d made my own manifold gasket when I took it apart. This is shaped and not reversible. I guess it’s for the engines original turbo configuration that it has a strange water way into the cylinder head at one end underneath cylinders three and four which doesn’t go anywhere. I’d made my gasket to fit perfectly, removed it, applied some sealant and then fitted it the wrong way. A fact I only found out when filling the car up with water and hearing it splash onto the floor. Whoops! Wondering if I’d cracked the head from using too much copper slip (still working hard to use up a tin of the horrible stuff) and hydro-locking a bolt hole or from running the engine with no water for a few seconds I slowly removed the manifold. Again, an easy job thanks to a little thought earlier. It was then that I saw the water way and gasket. I must have fitted it as a final job one day when tired. Anyhoo, new gasket is made and it allowed me to get some paint onto the areas which had been stripped from the petrol.
Oh, I also tinkered with the dashboard some more. I tried to use the film I had to coat it with and ended up with a horribly creased mess. So I went out and boat a can of spray paint and have it a quick blast.