"Akio Ohtori - RIP Oppo" (akioohtori)
05/08/2018 at 15:00 • Filed to: Project Dumpster Fire
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"Akio Ohtori - RIP Oppo" (akioohtori)
05/08/2018 at 15:00 • Filed to: Project Dumpster Fire | 7
| 9 |
Crusty!
Mostly good news on my Dumpster Fire Saab: it once again lives!
Over the last week or so it was treated to an entirely new cooling system, new vacuum bushings, and 4 gallons of fresh fuel.
The aforementioned “pumping marbles” sound heard at the fuel pump seems to have been solved by bleeding the fuel lines. Odd, but that is CIS for you.
I was also able to re-use the cold-start/ Lambda injector’s fuel line by just trimming it slightly. Fingers crossed the old, brittle hard line continues to hold.
Next up is to get it up on the ramps and install a hot start relay, then it should be road-worthy again.
Should.
Doggos for your time.
Future Heap Owner
> Akio Ohtori - RIP Oppo
05/08/2018 at 15:35 |
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Nice work! This is a cool project.
I went back to your previous post on this where you talked about your intention to replace all the cooling parts and mentioned that would include a new “thermo-switch.” What is that? I thought I knew all the parts of a cooling system but I’ve only heard of thermostats, not thermo-switches.
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Akio Ohtori - RIP Oppo
> Future Heap Owner
05/08/2018 at 15:42 |
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A thermoswitch is exactly what it sounds like: a switch that is controlled by temperature. While the thermostat regulates coolant flow based on temperature, these are responsible for electrical functions related to the cooling system.
This car has two thermoswitches. The one I replaced mounts to the radiator and is responsible for turning on the cooling fans when the radiator/ coolant temp exceeds its setpoint. The second, pictured the the 1st photo, is for the AC. If the coolant temperature exceeds a certain temperature (93C?) the AC compressor cuts out.
I assume this functionality is taken care of by the ECU in modern cars.
facw
> Akio Ohtori - RIP Oppo
05/08/2018 at 15:56 |
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Good doggos. Adequate Saabo.
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Future Heap Owner
> Akio Ohtori - RIP Oppo
05/08/2018 at 16:09 |
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Thanks for the detailed explanation!
I didn’t know that AC clutch cutoff was based on coolant temp. That temp is above the thermostat’s opening temperature, right? I suppose that’s why some people are convinced you should turn off AC when climbing hills or passing. In cars with ECUs it’ll disengage the AC clutch in those situations (probably based on load). Also explains why I haven’t heard of these: you’re right about the ECU handling this on modern cars, which are all I’ve ever worked on or studied about. Though I have heard of cars where the radiator fan is on all the time.
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Akio Ohtori - RIP Oppo
> Future Heap Owner
05/08/2018 at 16:25 |
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Yeah the AC thermoswitch is only in play if you’re overheating already, well above where the thermostat would be 100% open, and acts as you describe. This car also has limit switches on the throttle to detect when you’re floored (WOT) and disengages the AC then too. Both are to reduce engine load in extreme situations.
Urambo Tauro
> Akio Ohtori - RIP Oppo
05/08/2018 at 16:32 |
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I remember you mentioned that getting 5th gear again helped it run less hot on the highway. But it was still running a little hotter than it should though, huh? With this cooling system overhaul, did you find something that looked like it was a major contributor to that?
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Akio Ohtori - RIP Oppo
> Urambo Tauro
05/08/2018 at 16:36 |
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No smoking gun, no. My friend with the 83 was having similar problems and replacing the radiator solved them. Given that I’d done everything else, I figured this was my only choice. The assumption is the old one is corroded on the inside (from sitting so long) and likely has flow restrictions. The only direct evidence of this I’ve seen is the drain plug is quite corroded.
The old radiator is one of the brass and copper ones, so I am retaining it for a potential rebuild one day. The new one is made from aluminium and plastic and sadness.
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Future Heap Owner
> Akio Ohtori - RIP Oppo
05/08/2018 at 16:41 |
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Ah throttle limit switches make sense; those would trigger far more often than the thermo-switch. Thanks again for the explanations.
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Urambo Tauro
> Akio Ohtori - RIP Oppo
05/08/2018 at 16:43 |
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Hm yeah the radiator (stock AFAIK) on my brother’s ’91 is aluminium & plastic too. He’s already broken the plastic drain plug off...