www.RX7fb.com

so the Turbo II gearbox is done and the shifter modified to suit the FB's shifter position. The selector rod has been drilled, tapped and cut down and the tail shaft refitted dry to test the operation of the transmission.






It selects all the gears and the neutral switch gives a continuity signal when the trans is in neutral...

neutral switch...




I've hit a snag with the reverse switch though... I can't get a signal from it when the trans is in reverse. I've taken the switch out and still can't get any continuity across it.... anyone know why it's got 4 wires coming out of it... 2 red and 2 green..... I can only think it's for twin signals for some reason... no matter where I put the tester I don't get continuity. For info, when the trans is in reverse, the plunger to the switch is in the 'out' position and should, I reckon, give continuity.... therefore when the switch is out of the trans and the plunger is, by default, out, then I should get a signal with the tester.... maybe a duff switch?

switch...


If I can confirm that it's the switch then I can pull the tail shaft back off, put some sealant on it and bolt it back on properly. That will be another part of the jigsaw done.


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In my fc manual it calls it a reverse / 5th gear switch but no other info

myatt1972 wrote:In my fc manual it calls it a reverse / 5th gear switch but no other info

thanks, I'll have to download a FC/TII manual. I've been doing a bit of research and apparently it doubles up as a reverse switch and a 5th gear switch.... I don't need the 5th gear switch facility as that's only for emissions on the stock ecu.... presumably the position of the plunger switches for either reverse or 5th gear?
I only need reversing lights.... I'll have another play with it tomorrow... word is that they are notorious for going wrong and cost about £170.00 to replace..... so I won't be buying a new one of those then.

I have a feeling it might be something to do with the Motorised hood, as there are several things like ignition/handbrake that have to be set in various positions before the hood will operate?

That's a good call about the hood Pete... maybe that was the purpose of the neutral switch? can't think of any other use for it except maybe something emission related? I'm going to use it for a remote start.

Anyway, happy days, I've fixed the reversing light switch

I got the multimeter on it and no matter which position the plunger was in and which combination of wires I was testing, it was completely dead.

The switch itself comprises of 2 basic parts, the main body which incorporates the spring loaded plunger that screws into the tail shaft of the transmission and the switch contacts which are housed in a metal cylinder that's crimped onto the back of the main body of the switch.

Mazda dealers / vehicle technicians would test this switch and if it was dead would just bin it and fit a new one but we're old school home mechanics right? and a bit more ingenious than that ( plus I don't want to shell out £170 for a new switch).

So into the vice it went and I carefully hacksawed the crimp off it to separate the two halves of the switch.... only thin soft metal so it was done in a couple of minutes...





the two halves then pulled apart...





This revealed the components and workings of the switch which are simply 4 copper prongs that connect directly to the 4 wires coming out of the back of the switch...





and a long spring loaded plunger that is an extension of the plunger seen on the outside of the switch...





The plunger shaft just slides through the contacts giving 3 different signals depending on its position. It has plastic in certain positions that breaks the conductivity. On this switch the metal prong contacts were a bit dirty but the plunger was pretty horrible so I cleaned it up with an emery board, flushed the whole thing out with WD40, cleaned the contacts and put it back together and it worked fine

I then tried it in the transmission and again it worked perfect which means transmission modifications were also ok so that's great news.... the gearbox mod isn't difficult but accuracy is essential, especially when drilling the selector rod.... just a fraction out or if the hole isn't drilled in exactly the same plane as the existing hole and you end up with a box that's notchy or won't select a certain gear.

For future reference the pair of red wires to the switch( which are in turn connected to the long switch contacts) are the wires to the reversing lights..... the pair of green wires ( which go to the shorter switch contacts) give a circuit when 5th gear is selected. When the plunger is fully out that gives the signal for the reversing lights, when the plunger is fully retracted that gives the 5th gear signal.

I need to permanently reassemble the switch. There's no pressure on the bit that contains the contacts during the operation of the switch so I'll clean it all up externally with brake cleaner then Aradite the 2 halves back together.

Next job is to pull the tail shaft again, clean the surfaces again with my trusty brake cleaner and then rejoin them with some liquid gasket.

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Nice work Ian, and a good write-up so others who suffer this issue can confidently tackle this job when needed

fetched my car back today from its 6 month hibernation in Keiths barn ....... great to have it back on the road in the sunshine...











fired straight up and ran great on the 20ish mile run back home... the clutch pedal is a touch spongy so I'll have to bleed the clutch... selects the gears ok though.
Happy days are here again

back to the TII engine.....




Stripped the inlet manifolds, injectors, fuel rails and oil injecters off it to get it a good clean up...











then put it again dry.... new gaskets and injector seals on order from Mazda....

An issue with doing this engine swap on right hand drive FB's is that the turbo hits the steering box and because I don't want to shell out on another exhaust manifold I decided to flip the existing one over the throw the turbo forward away from the steering box.
Sounds easy enough but needs a bit of tweaking.
First, the manifold needs a bit cutting off the top to stop it hitting the LIM...




and the bottom of the lugs need grinding off it to stop it hitting the bottom engine bolt...





it then fits fine...





Next, for some bizarre reason the stud holes in the turbo aren't symmetrical so need re-drilling oversize to get the turbo to fit onto the manifold...






The turbo then slides onto the manifold studs but hits the LIM so a steel packer needs to be made to fit between the manifold and turbo to pack the turbo away from the LIM.
I made a packer out of some 10mm steel plate...











This has made the turbo clear the LIM.... whether 10mm is enough of a packer I'll have to see once the gaskets are on it.








By using a packer, I need 2 of these gaskets...





but Mazda want £50 each for them ............ so I'm going to make a couple out of some copper sheet.

I've ordered some longer manifold studs to allow for the 10mm packer and need the rest of the gaskets to arrive now from Mazda then I can build it up.


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Nice update Ian. It's cleaning up quite well aye! Turbo will definitely be a close one. Will it be okay being so close to the LIM? Those damn gaskets are expensive!!