Wot, not another '79 Targa resto thread

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PeterK
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

Thanks for the links. I've read the 'CIS Primer' which I devoured before I started playing. My CIS seems to run well, apart from the slight hunting just after first starting and the odd stumble when accelerating from low revs, so I've tweaked the mixture down slightly and we'll see how things change. I richened the mixture until the tick over went rough (which was very little), then weakened until it went rough (which was about 1/4 turn), then richened it back up about halfway.

My running-in schedule is
- 20 minutes at 2k revs to bed the cams in (completed)
- 500 miles below 3k revs (290 miles completed so far) of varied driving, using the rev range but not labouring the engine, looking for the occasional long downhill slopes to generate vacuum in the engine under engine braking
- oil & filter change, re-torque head studs and check valve clearances
- some more miles, gradually raising rpm limit to something more Porsche like :lol:
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deano
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Re: Wot, not another '79 Targa resto thread

Post by deano »

In case you haven't come across this K-jet (CIS) video, and others like it:

https://www.youtube.com/watch?v=a4fJAfXYxWk

Only suitable for geeks mind :oops:
Dean
1973T Targa MFI 334 met blu- under restoration https://www.ddk-online.com/phpBB2/viewt ... 28&t=67060
1980 924 Turbo, blu/grn tartan - restored
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

The Klassic Automotive videos are worth a watch
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

Good news - Original wheel makes a difference – steering is lighter and I can see the gauges at 40 – 60mph, so very useful when running around locally.

Not so good news 1 – the droning from my exhaust has returned. It would appear that if you go out with 2 exhaust baffles and come home with only 1, then the drone returns. Ebay order placed (£10.74 for 2 off 60mm motorcycle db killer baffles)

Not so good news 2 – I checked my fuel pressures again and I’ve still got issues with the cold control pressure (very low when tested normally, although rises significantly when pump is turned off). The car also smells very rich (garage also stinks after the car is left in it overnight), and the plugs were very sooty when I checked the other day, so bullet bitten and full WUR rebuild kit ordered from Germany. https://www.ebay.co.uk/itm/384627462068 ... Sw52Jgaubw

Better news – it was slow to close while I was watching, but the aux air regulator was nicely open when cold and after a drive, was fully closed. Revs rise to about 1200 when the engine is first started, and settle down later. Tick-over when warm is around 900. Still need to check decel valve and aux air valve (the other one). Still getting some surging about 30 seconds after a cold start, which I can sort by keeping the revs up for 15-30 seconds, then all is well behaved again. Hoping (is this technically allowable as a fault trace & fix approach ?) that 'sorting' the WUR will help address this.

Not so good news 3 - the rear fog light on the NS is not overly happy at its proximity to the exhaust exit, so some heat foil added. We’ll see how successful that is.


More good news – we (SWMBO & I) went out the other evening, so I took the 911. Apart from the smelliness (see above), the car was fine. The car was properly frozen at midnight (well past my bedtime, but never mind), but the heated front screen worked a treat.
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Re: Wot, not another '79 Targa resto thread

Post by jjeffries »

I believe that once you’ve refreshed the WUR, all will be right with the world.

Best of luck, John
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

Thanks John, I think so too
There is no downside to refurbing the WUR (cock-ups excluded), so all I have to lose is £80 and my time.
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

It’s been a while, but photos are included this time …
While waiting for the WUR rebuild parts, I decided to reset the ride height. The front was about right at 620mm (it was easy, so that got done a while back), but the rear was sitting a little high, probably by 20mm.
Image

So off into the garage.

Of course I never get distracted, so the first thing I did was reset the steering wheel. It was set 1 spline off from straight ahead, was really annoying, but I kept forgetting to sort it.

Back onto the ride height, and after a whole lot of googling, I decided that I would try 30’ swing arm / torsion plate angle, aiming for 605mm to the underside of the wheel arch.

I will detail what I did shortly, but suffice to say, I thought about things overnight, and did it all again today. Rather than just leaving the swing plate to torsion tube wherever I set it when I reassembled the suspension, I decided to check a few things.

Firstly, with the SC swingarms, I appear to have 50 or 60mm ride height adjustment. So, I elected to set the eccentric adjusters at about 2’ from maximum low, so that I have a little adjustment downwards, which will enable both sides to be tweaked to be the same ride height. I have more than twice that adjustment available to raise ride height. My logic is once set low, I am only likely to want to raise it if fully laden, like when I go to CLM (hopefully), so leaving more adjustment up than down.

I of course managed to get more distracted, although it was the post-person’s (politically correct for a change) fault, ‘onest guv. Firstly, yesterday I received my fire extinguisher, so had to fit it.
Image
Image

Hope that I never get to find out whether they work in the real world, but just in case I need it …….


Then today, my replacement exhaust baffles arrived. For scale
Image

And once fitted (this time with a locknut, so hopefully I won’t lose another)
Image


Enough of the distractions, so, wheels off
Image

Removed torsion plate cover
Image

Yesterday I moved the rear ARM drop link out of the way
Image
But today I didn’t bother, and managed to access everything I needed to without issue. It might make life easier when I have my 12mm allen key and try to adjust camber and toe.


I used a block of wood in my high lift jack to take the strain off the torsion plate
[Image

And disconnected swing / banana arm.
Image


With everything swinging in the breeze, I checked the torsion plate angle.
Image

Yesterday it started at 33 & a bit, and someone’s comprehensive chart suggested that I needed to remove 3 or 4’, so a target of 30’ seemed about right. Today, having changed the eccentric adjustment, I reset it to 30’


Having built the suspension fairly recently, the torsion bar came out fairly easily (after some levering with a pry bar). To get the torsion plate off the torsion bar I used mole grips and a pry bar.
Image

I know, don’t mark the torsion bar and set any localised stress points.


By playing with moving the torsion bar and counter rotating the torsion plate by an equal number of splines, we ended up with 30’. Unfortunately, once things were all torqued down, things had changed slightly
Image

So try again, and better this time
Image


Then, as they say in all the best manuals, reassembly is the simply reverse of stripping. Today, without driving, just bouncing on the rear, we have
Image


I’m expecting the ride height to settle a further 10-15mm, but can tweak just using the eccentric adjuster to get where I want. I’ve ordered a 12mm allen key, as I can’t get my 12mm allen socket into the camber adjuster. I did guess which way was more negative camber, but as I’ve ended up with about +2 rather than -2, it’s clear that I guessed wrongly.
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deano
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Re: Wot, not another '79 Targa resto thread

Post by deano »

I wonder if that nyloc nut insert will melt. I suppose you could switch it around so that it gets some air cooling, with a stainless washer or two to resist heat transfer. Otherwise an all-metal lock nut, or a self tapper instead... :cyclopsani:
Dean
1973T Targa MFI 334 met blu- under restoration https://www.ddk-online.com/phpBB2/viewt ... 28&t=67060
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

Yes, I expect it will melt, but there is an integral nut is where the manufacturer has punched a indent (the bolt hole) and the edges form a thread. The nyloc is therefore working as a locknut. If I had some thin nuts, I would have used 2 of them on each side (but I don’t, so I didn’t :lol: )
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Re: Wot, not another '79 Targa resto thread

Post by RobFrost »

Just looking at that scissor lift - I take it there are no external oil pipes then on earlier impact bumper cars? My 3.2 has them under the sill so I don't think that lift would work for me... Although mine is a backdate so maybe some sill cover has been removed?
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

My SC also has the external oil pipes under the cill modesty panel. The car sits on rubber pads, which I set to press on the least bad parts of the underside.
The lift came with 40mm thick pads but as my rear ARB drop links sometimes touched, I purchased some 60mm pads which avoid the issue. Downside is that I had to buy & cut up a scaffold plank to raise the car high enough for me to get the 60mm pads in place.

Lift is great & my only regret is not having done it earlier.
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

Allen key arrived, but a family trip to Centerparcs for my twin’s 30th birthday intervened. This was followed by Son in Law buying a motorbike, or more accurately, by SiL asking if I would ‘help him’ tidy the paint-work. As the lacquer was peeling in a few places, I suggested a light rub with 400 grit and I would re-lacquer. Well, after he had rubbed lightly back to the plastic !, a full respray was needed. So 3 days later we had
Image

Even though he bought direct gloss, rather than clear and base, it did look quite shiny]
Image


So, distractions out of the way, it was back onto the rear suspension.

I had noticed that the NS torsion bar was protruding, and the end cap / welch plug had gone walkabout. I knew this when I wrote the previous post, and had ordered a replacement (well 2 as I expect it to fall out again).
Image

Having removed the rear axle from both sides (again), so that there was no tension on the torsion bars,
Image

I did a bit of tappy tappy, and the bar moved in (still more tappy tappy needed here)
Image

A little out of chronological order, but the new plug was installed. As I am inherently lazy, and tried to do the replacement without removing the side cills and the torsion cover, there was not a lot of room to swing the hanner. Having bruised most of my fingers, I got smarter and concocted a plug holder
Image


Both the tappy tappy and any attempt to fit the new end plug were not entirely successful, so I did have to open up the torsion cover in the rear wing. Hqving drifted the torsion bar in a little further, the plug was fitted.
Image

Still not happy that it will stay in place, even though I did use some epoxy weld to encourage it. The end of the torsion bar plate / thingy is not pristine and therefore not really gripping the plug very well. Good job that I bought 2 plugs.

Anyway, once that was done, the ride height was tweaked up 5mm on the driver’s side and down 10mm on the passenger. I set camber to maximum and a middling position for the toe. Once the car was back on the ground and the suspension bounced (need to drive it to ensure that it has fully settled), the camber was –3 and the rear ride heights both a 605mm to the centres of the wheel arches.
Image

So that’s a result. Now that ride height is (hopefully) sorted, I plan to try my local tyre place that have a laser alignment rig and tweak. I’m aiming for 1.5 to 2’ on the rear.
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Re: Wot, not another '79 Targa resto thread

Post by PeterK »

So now it was time for the WUR. Step 1, remove it
Image

And prepare my workspace – notice the strategically placed coffee
Image


The good news is that my kit came with a link to instructions. The less good news is that the instructions are only available in German. My technical German is not brilliant, but I got the drift (I hope). So next, remove 4 screws and the top half comes off, quickly followed by the springs and the little finger bouncing across the table.
Image

As was suggested by someone earlier, it is quite possible that the finger had been displaced, thereby causing my low cold control pressure.

This is the heater element
Image

And these are the springs
Image

Remove the clip that retains the heater plug
Image

Undo the retaining nut and gently remove the heater element
Image


Fit new rubber o-ring to the underside of the electrical plug and reassemble
Image



Then onto the top section
Split the two parts of the top section, then drill out the 4 aluminium rivets seen here
Image

Then pull out the old diaphragm
Image


Now came a bit of trial and error, starting with test fit new diaphragm
Image

Using the screws provided, I then bolted it in place.
Image
Image

I then realised that I should have fitted the new joining piece first
Image

Before bolting the plates on
Image

Along with the gasket for the top-half sections, and securing
Image



Then the springs and finger were added to the base part
Image

And finally bolt the top half to the bottom half.
Image

I hopefully won’t need it, but while I was there ……..

I did the adjustability modification, drilling a 4mm hole about 10mm deep, tapping M5 (yes I know the tapping hole should have been 4.2, but I haven’t got a drill bit that size), and adding an M6 washer (M5 was just a smidgen too small diameter), a nut and the M5 bolt. By tightening the bolt, it will pull the plug out, moving the heating element, reducing cold control pressure and thereby enriching the mixture. If I need to lean the mixture (lower CCP), I can loosen the nut and gently tap the head of the bolt, thereby pushing the bung further in / down.


Of course, as I've not refitted it yet, I have no idea whether I have done things correctly and/or how much tweaking it will take to get the control pressures anywhere near where I want them, but as they say, tomorrow is another day
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Re: Wot, not another '79 Targa resto thread

Post by hot66 »

RobFrost wrote:Just looking at that scissor lift - I take it there are no external oil pipes then on earlier impact bumper cars? My 3.2 has them under the sill so I don't think that lift would work for me... Although mine is a backdate so maybe some sill cover has been removed?
I have a scissor lift and you use rubber mounting blocks between the lift and the body so any sill pipes are nowhere near the lift
James

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Re: Wot, not another '79 Targa resto thread

Post by Rustytubs »

Nice update, most people don't like playing with the K-Jet system but its worth taking the time to understand it.

The adjustability modification is a good and having control on the pressure of the system will give good results if you can set it up properly with a gauge (over time they do loose control pressure and the fuelling can get lean at higher rpm). The system is very similar to that on the 16v mk2 Golf GTI and we always found more power on those after this mod was done.

Keep 'em coming
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