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Cars SAAB

Ignition timing

Found since getting Helga back on the road that she was misfiring under boost. At some point I’d taken the distributer off and lost the timing. Simple to sort normally, but what made things more confusing is that the timing marks have been machined off due to the flywheel being lightened. There were three lines of paint but no indication of which one was TDC. Eventually sussed it with the old screwdriver down the #1 plug hole trick. It was the yellow line!

She’s running great now, though one potential issue I spotted is that pressurising the vac capsule to around 15psi only retards the timing three degrees, whereas I thought stock it should be more like six, so from 16 to 10 degrees. Currently it only goes back to 13, which I think might be causing the boost to be slightly erratic in how far it will go. This is the opposite of what I was expecting because I was told when I bought the car that the distributer had been modified to retard further on boost, so the off-boost timing could be advanced more than stock.

In the middle of all this the bonnet cable snapped at the end that attaches to the pull, so for now that’s been replaced with some mole grips.

While I was diagnosing the misfire I did a compression check, the results seem good enough so the head gasket swap can wait. I’ll end up doing it eventually because I’d like to replace the timing chain and tensioners, plus I’ve got an uncracked exhaust manifold ready to fit. Of course that’s not necessarily a head off job but I’ll bet at least one of the studs will shear.

Cold compression
1 125
2 120
3 130
4 120

Hot compression
1 120
2 120
3 125
4 115

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Cars SAAB

Back on the road

Progress on Helga since the last post on repairing the outer arches has been a bit slow, but she’s back on the road. The front inner arches have been repaired, etch primered, seam sealered and schutzed.

More filler on the front wings, and a coat of filler primer. That’ll keep it protected until it gets warmer when we can address the paintwork properly.

Naturally I then took the interior out. The carpets were sodden, looks like water has been getting in behind the pedals past where the cabin air intake thingy meets the bulkhead. Fixed the missing vacuum line for the heater controls and put the interior back minus the carpets for now until I’m happy the leak is fixed.

And home! Looking very scrappy but she made it no problems.

She was struggling to start after being stood so I’ve fitted a new Varta D24 for good measure. I’m really pleased that the new temp sensors seem to have done the trick, she starts almost instantly and idles perfectly now.

Had a spare full interior for Helga in really good condition, apart from the stitching was coming apart on the driver’s side base so I spent a little time stitching it back up. I’ll save it ’till the outside is tidied so she feels like a new car.

For a bit of fun I drew up the missing 16v badge for the bootlid. Not delighted with the print quality but it looks okay painted.

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Cars SAAB

Saab 900 front arch repair

Time to replace the front arches on Helga – once I started poking at the bubbles it was clear they needed replacing. Luckily Saabits offer weld-in replacement sections, and I’ve got a friend with a welder.

Cut out the old

It’s not technically possible to get the front arches as repair panels – the trick is to buy rear ones but swap left to right. Still, I’m not sure why the curve of the new arch was quite a bit smaller radius than the arch we cut off because I’d read they’re supposed to be the same.

While my mate Rich was doing the welding I fitted a new water pump, thermostat, ECU temp sender and fan temp switch along with fresh red antifreeze. I’d already done the gauge temp sender and the radiator looks pretty new so that’s all of the cooling system overhauled. The old pump was binding at certain points and it was weeping slightly because the mounting face hadn’t been cleaned up properly last time. Hoping the temp sender helps the wonky running and the others are just for luck but it should all go towards better reliability once she’s back on the road.

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Cars SAAB

Oulton Park Gold Cup 2017

Every year we go to the Oulton Park Gold Cup, and this year was Helga’s turn. Had a very eventful journey, blew off a boost hose early on and that started a cycle of constant stops to refit it. I think it must have blown off a dozen times. Got so fed up that I disconnected the APC valve to drop to base boost but the pipework is a bit stretched and doesn’t have swaged ends, and disturbing it once seemed to start the cycle.

Grabbed a couple of Mikalor clamps from the track shop to try to hold the pipes together a bit better which was working great on the way home until I went for a full bore overtake of a corsa, and as I drew level, -pssst!-. This time it was at the other end of the offending pipe. Much easier to put back though because it wasn’t underneath the washer bottle. To effect a proper fix I just need to find a longer silicone jointer that is stepped because one pipe is ~56mm and the other is 51mm, plus there’s very little overlap of jointer into pipe and the pipe isn’t swaged.

As I stopped at the next junction I came to after putting the pipe back, a cloud of white smoke plumed from under the bonnet. The distributer chose that moment to blow its seal and wee oil onto the turbo heat shield. I’ve got a couple of other spare distributers but from later cars, so I’ll have to work out if they’re compatible.

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Cars SAAB

Head gasket false alarm

Dirty expansion cap
Uh-oh

So half way back home with Helga I noticed the coolant level was just above the minimum line, then when I stopped to check it yesterday the header tank was empty. Filled it up and kept a close eye on it. It was using about a litre per hour’s driving, and the header cap was collecting sludge.

However, happy news for once! Having bought a head gasket kit I noticed a damp patch where the coolant lines enter the bulkhead. Turned out the hose had rubbed through on the alternator bracket, then been taped over with electrical tape. I drained and flushed the system, replaced those hoses with silicone from Babs, correctly adjusted this time to avoid the alternator. As a double check I popped the cam cover off to find no evidence of water in the oil so I’m going to see how she runs now.

As a bit of a treat I swapped the side indicators back to orange, replaced the bonnet badge and ground back and kurusted some of the surface rust from the inner wings. Also replaced the temp gauge sender so the gauge works now.