by "Urambo Tauro" (urambotauro)
Published 11/06/2017 at 12:00
by "Urambo Tauro" (urambotauro)
Published 11/06/2017 at 12:00
Tags: Saab 900
; project
; wrenching
STARS: 7
Stupid rain. Here, have some video of the running engine:
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(This footage is from last week, when we finally got it running for the first time. And yeah I know, that was some really meek pedal-pushing. We didn’t want to stray very far from idle speed until it had a chance to get to operating temp anyway. We haven’t even checked timing yet. But FWIW, it sounds pretty good so far. BTW, this is with no exhaust after the oxygen sensor, and there were some fumes leaking into the cabin.)
As for this week, we wanted to at least make some progress before the rain hit (no room in the garage), so we started by draining the coolant while chasing down the not-charging issue.
The alternator is sort of accessible, but kind of a pain. So we started by looking at things that could be done while leaving it in place.
Alas, cleaning the ground and positive connections didn’t get us anywhere, but we did find some issues with the voltage regulator.
Despite the polished tips indicating contact with the slip rings, the brushes were still too short according to the manual’s specs. There was a chunk missing from the resistor’s insulation too, so a new regulator is on its way. *crosses fingers*
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Surprisingly, after sitting for just a few days, the engine now seems hesitant to relive last week’s glorious moment. It cranks, but it won’t run now. So we pulled the spark plugs, only to find all of them wet with gas. So we worked backwards from there, and when we reached the coil, we found it giving inconsistent readings. Even cleaning the studs didn’t seem to help provide a steady readout.
So we pulled the coil, and tested it again on the bench. This time, it actually gave a solid but out-of-spec resistance reading. Welp, time for a new one, I guess. Hopefully that’s all it needs.
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With a new coil and voltage regulator on the way, we continued draining the cooling system. Unlike my car, which has only a drain plug on the radiator, Saab was kind enough to include a block drain.
Of course, there’s always some coolant left in the system, but between the block drain and the radiator drain, we were surprised to get only about 5-6 quarts out (10.5 quart capacity). Fortunately, there didn’t seem to be much of a mess to flush out. Just a few bits of sediment here and there.
The old coolant, despite looking fairly green, was only good down to about 5°F for freeze protection, according to the tester gauge (potato pic
here
). So since we can’t seem to drain the entire system at once, we’re going to run distilled water through it a few times to dilute what’s in there. After that, we’ll add fresh antifreeze.
Unfortunately, my brother accidentally over-torqued the radiator drain plug, twisting the hex right off, along with the hose fitting for tidy draining. We tried to remove the rest of the plug with a fluted bolt extractor, but it just shaved bits of plastic away instead of turning it loose.
It probably won’t leak, and we can still disconnect the lower radiator hose for draining, so maybe we’ll just forget about using that drain plug. It would be nice to get it out and install a new one, though. Maybe we’ll have better luck after the engine is running again, and can warm it up.
"Tristan" (casselts)
11/06/2017 at 14:00, STARS: 1
I’m loving all the OG Saab revivals happening around here lately.
"jminer" (jminer)
11/06/2017 at 15:46, STARS: 1
While I can’t say specifically for SAABs, on many other brands a less than perfect charging system will cause all sorts of ignition gremlins. A battery is there to buffer and absorb, but it can’t provide the 14 volts that most components expect.
If you get your charging up to snuff I imagine it’ll start running much better.
"Urambo Tauro" (urambotauro)
11/06/2017 at 16:17, STARS: 0
I think so too. I don’t like that we’re still using the old plugs, wires, and distributor cap/rotor. They don’t look bad , but I’d really like to give this thing a full & complete tune-up, as we have no service records on it.
But it’s my brother’s money, and for now, it needs to be put towards the things that need the most attention. He still needs to overhaul the brakes, get a new set of tires, and replace a good chunk of the exhaust sytem, plus a bunch of little nickle-and-dime stuff. It’ll be weeks before it’s back on the road.
"shop-teacher" (shop-teacher)
11/06/2017 at 18:13, STARS: 1
Little by little!
"jminer" (jminer)
11/06/2017 at 19:42, STARS: 0
Yeah, components like plugs, wires cap and rotor are a good idea to replace on a new-old car anyway but I’d hold off on anything more serious until you get the electrical system in good working order. I’ve thrown a lot of money at ignition and carb problems with it ending up being a bad ground... I was both elated and furious when I finally figured that one out.
