Wot, not another '79 Targa resto thread

[PeterK]

A long 36mm spanner, but I only managed the tiniest of movement before ‘other things’ limited any further spanner turning

[PeterK]

Well, you live and learn ....

The pins that locate my targa top into the top of the front windscreen surround were very loose - the threads were less than wonderful. As a temporary measure, I used some PTFE tape and soldiered on. I got a replacement pin for the worse side, but it was about 5mm longer than the original, and wouldn't fit into the 'hole', holding the targa roof waaaay tooooo high.

Fast forward to buying a pair of replacement pins from Porsche Guildford, which arrived today. They were also too long !. The pins that I have (original to the car as I got it) might well be for the earlier (upto '77) targas. However, before sending them back, I had a play in the garage, to see if I could 'finesse' them to fit.

Measuring them, the diameters of the 'long' and 'short' pins are the same at a nominal 10mm, and the lead in / pointy ends are the same. The difference is only in the length of the straight/parallel section of the main part of the pin. As the original ones fitted, why were the new ones not fitting? Can you see where this is going yet ???

The pins fit into a brass 'hole', but I'd painted the car, including the inside of the 'holes'. Removing this layer of paint, cleaning the hole with a pointy thing, and a slight adjustment on the trim pieces that fit above and hold the windscreen seal, and tah dah, the pins now slide into the holes. I attached the new pins to the targa roof, refitted it and hurrah, the targa top drops down nicely, so hopefully, no wind noise now !.

I did need to seriously modify the targa side seals, but the final part of my fitting issue was simply a layer of paint. The shorter pins were I assume, just locating into the 'holes' but not sliding down into the recess correctly, hence holding the top slightly proud. Who'd of thought, eh.

Happy bunny now.

[PeterK]

Oh, nearly forgot. Took the car for a pre-MOT, as I needed to check the brakes, adjust the headlight aim, etc. Headlights needed a slight adjustment, the OS handbrake needed a smidgen more adjustment to match the NS, and a bolt underneath was not fully home. Other than that, it got a clean bill of health, so MOT proper booked for next Friday.


Done a whole 140 miles now

[PeterK]

Well, yippedy do dah, we now have an MOT ticket

Yes, I know that I don't need one and it should not have been in doubt, having done a pre-test to check brakes, set headlamp alignment, etc, but I was a tad nervous before the test. Really strange, as I'm not anxious with any of the family's dailies.

[RobFrost]

Well, yippedy do dah, we now have an MOT ticket

Yes, I know that I don't need one and it should not have been in doubt, having done a pre-test to check brakes, set headlamp alignment, etc, but I was a tad nervous before the test. Really strange, as I'm not anxious with any of the family's dailies.

Reassuring to have somebody check it all over though.

[PeterK]

Absolutely. That was always the plan - I know the MOT tester well and he did me a thorough job

[PeterK]

Took SWMBO for a ride in the beastie yesterday, to see friends, about 30 miles each way. Surprisingly this was at her suggestion.

I'm informed that it was not cold, not too loud, but a little bumpy & with some wind noise (the car, not me) - a bit like the Midget of her youth.

About 210 miles down, 290 to go until oil change and head stud & valve clearance checks. Need to hurry up, as CLM is rushing ever closer.

[PeterK]

Been attending to a few little niggles recently.

While ‘adjusting’ something under the dash in the front, I had I inadvertently knocked a heater pipe and the wipers hit it, making a clicking noise. Easy fix.

While driving SWMBO the other day, I noticed that we could see daylight past the side window frame. I set the frame position to give a good seal before I finally tweaked the targa top into place at the front. It needed a further tweak, which took less than a minute to do, but of course I had to dismantle the door pockets, handles, card, etc, then refit afterwards. So around an hour to do a 1 minute job. Sounds familiar.

The door seal also sometimes hindered the door shutting, so I removed it and refitted it with better clearance around the rear, bottom corner.

The sliders on the heater controls were stiff or ‘bounced’ back from one or both ends of their travel. Having chatted with Jonny, I disconnected the driver’s side diverter valves, and adjusted the passenger side on its own. Once they were moving sweetly, I reconnected the driver’s side and adjusted as required. The red lever wouldn’t play ball, but this was due to the cable bending at the slider end, rather than pushing the cable through to the diverter. Recognising the difficultly in finding good replacement cables, I bought some 1.5mm piano wire and just replaced the core. So all working well now, even though I’ll probably leave all of them in the middle position. While I was in there, I replaced one dodgy bulb and a failed one. They were working when I originally refitted the heater controls, but that’s life.

Even with the auto heat set to off, I was still getting some heat in the car. With the car up on the lift, the N/S flapper valve was not opening fully, and so needed a quick adjustment. Need a run out to check that this is now sorted.

My whale tail didn’t come with the mesh grills, so I had bought and fitted some black mesh. Unfortunately it hung down a bit, so I added some supports / bracing. I made them from aluminium flat bar, painted satin black. I’d also made some 90’ aluminium bracing to fit under the engine cover, to spread the loading from the whale tail. Andrew (Fat Fuchs) kindly sold me one of his genuine spreader bars, so after cleaning & painting, this was installed while refitting the tail.


My aircon blower is powder coated, and this coating contains some silicon. The drain ports are glued on, but decided they would make a break for freedom, so I sanded some of the powder coat off and epoxied them back on.

Finally, my rear fog lights were not very visible (being sat in a box in the garage may have been partly to blame), so I drilled some holes, added some bolts and as no-one has run into the back of me, they must be working!


In other news, and on the assumption that I will manage to complete 500 miles and get the tracking alignment , oil change, head stud re-torque and valve clearance checked (& that nothing falls off in the meantime) done in time, and therefore take the 911 to Classic Le Mans, I’ve been buying. I now have spare bulbs, 2 hi-viz vests, beam deflectors and a warning triangle to add to my tyre inflator.

[PeterK]

Confused of Crookham Village here.

Decided to check my CIS pressures yesterday. Connected my gauges and cobbled a power feed to the fuel pump (via pin 30 of the red relay). Couldn't just link out the relay, as I have an immobiliser, which would keep timing out.

Test 1 - system pressure (valve to WUR closed) - 5.2b - happy chappy
Test 2 - cold control pressure (WUR electrically disconnected, valve to WUR open) - 0.6b - What ??

Stopped the pump, and the cold control pressure immediately jumped to about 1.6b, which at 17'C (WUR temperature via IR) was what I expected.
Turned on pump and CCP dropped back to 0.6b, turned off pump and it climbed back to 1.6b. How does that happen ??

Checked all my connections for tightness, opened & closed valve a few times, electrically connected WUR and then CCP and system pressure both 3.8b, no matter whether I had the WUR in circuit or not ???

Took everything off, started the engine. All fine, except the hunting / surging for around a minute while things warm up (which is why I was checking pressures), then all fine. Drove well (up to my running in limit of 3k revs)

So my learned sages
1 - why would CCP be low unless pump was turned off ?
2 - why would SP & CP be the same ?


Tempted to rebuild the WUR and make it adjustable while I'm there. Probably also ought to check my AAR while I'm playing.

[deano]

OMG - sounds like you really understand the CIS system, which seems to be quite rare - my experience of it and niggles found on my Two-four Turbo CIS drove me absolutely crazy!

I did disassemble and clean my WUR once, with carb cleaner, and my warm-up was even worse afterwards. One of the issues that I had when it came to bench testing it that none could tell me how much that bimetallic strip is supposed to deflect at temperature (the heating element seemed to be working fine). Other Two-four people were sending theirs away for refurb at great expense and months long lead-times. I'm sure you're aware already, I think ultrasonic cleaning is the way to clean the fuel channel out properly....I think there are lots of things in the system that can also cause shaky warm-up.

Good luck!

[RobFrost]

I know nothing about CIS but pumped fluid can have lower pressure if a) the fluid is being sucked out of the pipe in question by the pump or b) Bernouilli's principle is significant, which happens when there is a fast rate of flow past the spot where you're measuring.

[PeterK]

Thanks Rob
The pump pushes the fuel around the system and back to the tank, so couldn’t cause low pressure at the gauge, but the Venturi effect is definitely plausible.

[PeterK]

A plausible explanation for my CCP being low (except when pump is turned off), is the venturi effect of fuel passing the gauge port. As the car starts well (normally – more later), I’ll leave the WUR alone for now.

Been away teaching yachting again, but back now so time for some more dabbling - the engine bay fan didn’t run. Here follows my fault-finding, but if that bores you and you want to jump straight to the laughs (for you, not me), go to the end.


Anyway, good news first, the slight adjustment to the NS flapper valve has fixed the issue with there always being some heat coming into the cabin. However, the engine bay fan was NOS and worked when bench tested, but hadn’t worked since installation and autoheat fixed. So, into fault finding mode. First, check the fan still work – yes. Time for the wiring diagram.

Check that power from the relay socket runs the fan – yes. Is the relay switching on – not at the moment – change relay – still the same. Where does the relay get its power from ? That will be 2 of the rear fuses (main power for the fan and power to the switching contacts). Fuses all fine and power reaching the relay socket.

So what switches the relay – that will be earthing through the starter. I guess that when the starter solenoid is engaged, the 12V turns the fan relay off, maximising power to the starter circuit. When the starter is not powered, then there is enough of a route to earth to switch the fan relay.

So where’s the wiring to ground then. Via the heating switch - WTF is that. That will be the micro-switch in my autoheat, so that means removing the autoheat again. I had checked the micro-switch when I rebuilt the autoheat, but things do fail. No, microswitch is working. By-pass switch – relay still asleep. Bell out the wire from the autoheat microswitch to the relay – nada. That isn’t helpful, so run new wire. Bypass microswitch and fan runs (when I fitted the relay again). Hurrah. Add in microswitch, set autoheat to something other than off, and the fan runs. Switch autoheat to off, and the fan stops. Success.

Ha, but how quickly fate can kick you in the nether regions.

I had moved the 911 out of the garage to do a brake check on elder twin’s Fiesta, then moved it back in. We’re now a few hours later and it won’t start. It sort of farts sometimes when the key is first turned, but then the engine just spins over, like there are no sparks. Oh dear.

First check – remove the fan relay, just in case the fan is interfering or giving volts where volts didn’t use to be. No change. Check for fuel – seems fine. Check immobiliser – seems to be doing what it always did, but should really pay more attention in case it does start doing different stuff in the future.

First rule of fixing 5h1t – start with what you touched last. That will be pulling the fuse / regulator plate out of the car and having the wiring draped over the engine like loose intestines (sorry if you’re trying to eat). So, pull the panel and all the wiring out again, and check for trapped wires. None obvious.

Check airbox screws – seem fine and pop-off valve sitting down.

Bypass fuel pump relay – pump runs, engine doesn’t.

Quick chat with Jonny, to bounce ideas. Nothing obvious missed.

Check for sparks – use timing light draped around so that you can see it when turning the key. Top tip – don’t let the cable get into the fan. Good job that the car didn’t start, but the timing light still took off like a scalded cat. Slowly rotate the engine backwards and wind the timing light lead out of the fan . What a plonker.

Drape the timing light wires more carefully, spin the starter and sparky sparky light from the timing light, but unfortunately, not from the engine.

So, we have air, fuel and sparks, but no broom, broom. So do we have the right things at the right time ?

Pull CDI box and reload software, just in case I had managed to send a spike where a CDI box doesn’t like a spike. Software reloaded and ignition map checked – all as loaded, but still no joy with starting.

Pull plugs. Oh my goodness gracious me. Dirty and very wet. Drive to local motor factor store to get a new set. Store temporarily closed. Drive further to Farnham where Halfords and another branch of the motor factors are next door to one another. Halfords had two thirds of bu$$er all in the spark plug department and this branch of the factors is permanently closed !. So, drive to Aldershot ECP. They list 2 plugs for the SC, of which they had none of one type and only 3 of the other. Checking the plugs that I had in the car (with surprising foresight, I had actually taken one of them with me), they matched it to an equivalent NGK BP8ES, so I got a set of those. What plugs are others running now – I thought that the 8’s were right in the day, but 5’s are more often used today, or is that just in the US with their $h1te petrol ?.

So new set of plugs fitted – this will surely work. Nope.

So, start again. This time when checking the airbox, I realised that the pop-off valve o-ring was partly out. Popped it back into place, turned key and engine fired into life.

Moral of this – when you check something, keep your eyes open !.


In other news, I then gave the car a 25 mile jaunt around town, with a couple of blats (under 3k revs, of course), so 290 miles completed now. Tweaked the fuelling (was still smelling a bit rich beforehand) and in a rush of blood to the head, vacuumed the inside.

Also, I was finding the steering quite heavy, with 7” front wheels and a small Prototypo steering wheel, plus I couldn’t see the speedo between 40 & 60mph. Anyway, original steering wheel is now back on, and I’ll see how that goes next time out.

[deano]

[jjeffries]

Peter,

There’s a lot of very good stuff on Pelican about CIS, much written by a guy called Tony who goes by boytsc911 or something like that, from the Philadelphia region; he also rebuilds the system components. He can be a bit tough on those who come with questions but have been too lazy to check the basics … “doesn’t suffer fools”, etc but really is a lovely bloke and generous with his time. There’s also a good document out there called the “CIS Primer” if you can find it.

I’m in the US and have an 82 SC Coupe and am a big fan of CIS … my car runs great with it and I think the throttle response is better than L-jet or early Motronic systems. Just my view, but when you get yours right it will be straightforward to keep it that way. I don’t happen to see the need for an adjustable WUR.

What’s your self-imposed low RPM Running In timetable? I’d have thought that a once your cams were bedded-in with valve rocker arms and the first oil change was reasonably clean, you could/should give it some welly? That said, I’m no professional.

Best wishes,
John