Hey folks, long time no speak! Been loitering around here less and less since work barred kinja websites so I can’t peruse at lunch, but thought I’d keep in touch with what’s been happening. Stick with me, it’s been a busy one!
Not long after fixing it, it started running rich again which similar symptoms to the last time (that was fixed with a new rpm sensor).
However, it would only do it while it was wet and cleared up when it was dry so playing around with the sensor so figured it must be something electrical with water ingress. Fiddled about with the sensor and noticed that the seal at the end of the wire was letting water in. ‘Aha, gotcha!’ I wrongly thought. Replacing that didn’t help. Bugger.
After months of on and off searching about, I noticed this little shitter:
Notice the tiny little drip poking out of the sheathing for the white wires at the top. This bastard was tracking out of this drain hole in the engine cover...
...soaking into this braided section of loom...
...and dripping out directly on top of the plug for the ECU! Man that took some figuring out! However, with everything cleaned, dried and waterproofed the running issues improved massively! Big success :)
Also, I hadn’t been idle while I was scratching my head about this. One of the things that bugged me about the car was the awful gearchange. Even with the phosphor-bronze bush it was still not great, and the gearbox was already showing the strain a little from just 130bhp and had started being pretty reticent to get into reverse...or fifth...or first...or any gear a little too quickly.
There’s a much stronger gearbox that people sometimes put on Uno Turbos from a Punto GT (which I can also fit an LSD to!). The only issue is that the gearchange is on the top so poses some problems when you try and put it in an X1/9. I read about someone converting one using MGF cables so figured I’d start there. Here are the two next ot each other:
The MGF linkage seems like a pretty good design. The only issue is it’s bloody massive. The previous chap only shaved down the counterweight and bolted it directly to the tunnel, but that required a modified centre console so I thought I’d have a go at cutting it down to fit. Shaved it down to:
With a bit of modification it’ll slot down into the gearbox tunnel.
Had to shave down the rotating part to clear the tunnel, and relocate the window switches but it fit!
At this point, feeling very smug for myself, I realised that the chap who used the MGF cables never got to the end in his thread. Turns out, they’re much too long...
While I was scratching my head around that I clearanced the body to fit the gearbox...
...and came up with this:
The bottom picture is the new cable end. The yellow is an M10 threaded sleeve which threads snugly onto the rubber of the MGF cable (I tested it with an M10 nut which held on pretty strongly so a 30mm run should be solid. If not I’ve bought some rubber-to-metal glue). That slots into an M16 threaded sleeve (pink) and is welded in place.
A 30mm (or better 35mm) M16 bolt (light green) is threaded into that which clamps it against the gearbox bracket (brown). An 8mm hole is drilled through the M16 bolt, and into that is pressed an 8mm hard nylon tube from an air line to provide a bearing surface (dark green).
The upper picture is the swaged on threaded rod that connects the cable to the gearbox arm (green). Onto that is threaded an M6 female rose joint (purple) and a locknut (red). The light blue is an M6 nut with a couple of tabs welded on that bolts to the first rose joint, and into which the pink male M6 rose joint threads with its locknut. The second rose joint then bolts to the gearbox.
The reason for having two rose joints is that the gearbox arm describes an arc as it moves, so the inner rose joint allows the outer one to follow that arc. Without this, the swaged rod would bind in the M16 bolt (or you’d have to widen the central hole through the bolt to allow for the movement which would make it wear oddly). The stock cables get around this by having the nylon tube that supports the rod swivel at its base.
Overall, the double-linked rod is only a couple of millimetres longer than the plain rod (could be less if you had half-nuts for locking, but I’m not sure how good of an idea that is).
Two weeks later and we had a working gearchange!
Man those clacky noises are satisfying :) Nice feel with the rose joints as well, although will need to compare that to the added vibration coming back through them when it’s running.
The shortened cables worked a treat. Bought two long MGF cables and cut them both down to size (the short cables would have worked for the shorter of the two, but they’re always in worse condition than the longer ones second hand). Here are the dismantled bits for it.
Unfortunately, at this point I discovered that one of the linkages operated the gearchange in the wrong direction :S so reverse and 5th were on the left, and first and second on the right. Not good.
Luckily, the MGF linkage isn’t overly tricky to swap around if you have a decent welder. Little swingy arm from the right to the left and we’re good!
Stuck everything together, and fixed the window motor switches into some blanks on the switchpanel and the linkage was sorted :)
Then it’s just the niggly little bits to fix. First off was the old engine mount not fitting nicely. Bit of fabrication with some Ford Cortina rear leaf spring bushes and I came up with this:
Next was the speedo drive. I should have changed this for the X1/9 type when I had the gearbox open to fit the LSD, the issue being that the speedo cable on the Punto is much bigger. Some headscratching, some nicely fitted brass square tubes and some chemical metal fixed that :)
After that was the alternator. Because I’d also fitted equal length driveshafts (Uno Turbo Mk2 intermediate shaft and a second X1/9 LH driveshaft), the alternator mount had changed place slightly. Quick chop and weld of the tensioning bracket and it was all good :)
As a bonus, the Punto gearbox comes with a neat lightweight gear-reduction starter which saves 2kg. Combine that with all the bits and pieces I’d chopped out of the linkage, and the lighter gearbox mount, the whole swap only added 1.8kg despite the beefier gearbox and equal length driveshafts.
Last little niggly problem was another headscratcher. Bled the whole system up using the Punto GT slave cylinder, but the biting point was on the floor of the car, right at the bottom of the pedal travel. According to parts catalpgues there’s two types of PGT slave cylinder, one with a 25.4mm bore and the other with a 20.6mm bore. The latter is discontinued so I’d bought the former, which evidently didn’t work with my particular setup.
Spent bloody ages looking for a NoS slave cylinder, but eventually came upon a Fiat Doblo diesel that uses a 20.6mm slave cylinder. Had a weird quick-disconnect fitting which I had to carefully cut off and tap for a banjo fitting, but that was the last piece of the puzzle :)
Works beautifully, and the LSD is great fun :) dropped the RPM on the motorway from a heady 3800 at 70 to a much nicer 3200.
Had a couple of thousand trouble-free miles before I realised the temps were climbing after long runs again. Seemed like it had trouble bringing the temperature down after it was raised above the fans cutting in. Started with the easiest fix by fitting twin 9" fans :) one compared to the old beastie:
Better, but still no dice. Noticed a couple of coolant spots under the car so my new stainless coolant pipes weren’t sealing properly. Added some flanges and switching back to good old jubilee clamps from mikalors fixed that.
Still no dice.
Next, we noticed that if you upped the revs it would bring the temperature down a bit quicker. I’d replaced the water pump with the timing belt recently, but had to go through a couple before I found one that I thought was built properly (and even then it was only the best one I could find). Perhaps the end-clearances on the pump are a bit wide on repro parts. Whipped the water pump out (again) and my suspiciouns were confirmed. Haynes figure says 0.8-1.2mm end-clearance and we had variability between 1 and 1.5mm.
With a bit of grinding, and using sealant instead of a gasket I got the clearance down to a uniform 0.5mm. Bit tight, but doesn’t touch even when hot. Time will tell of that fixes it!
One of the other causes for the cooling problems could be head gasket issues, which would fit with the slightly rough running at idle. Borrowed an aircraft mechanic mate’s compression tester and got some not-so-great results. Plugged 80psi in, and got 76, 68, 66, and 78 back. Apparently those numbers in isolation aren’t particularly bad (66 would still be airworthy), the spread does seem to indicate that there’s something up with the middle two cylinders.
Rings for these engines are very difficult to find, so I’ve been on the eye out for a set before I take the top off and see what’s going on. Either that or save up and get a forged set, rebuild the R32 Skyline turbo I have for it, and swap over to the PGT management I have for 180-230bhp ;)
That’s it for the Fiat this year! At nearly 2000 words I figure I’ll do separate posts for the Spitfire and other projects ;)