FurryWrecker911
SCCoA Member
Edit: SOLVED! The vacuum solenoid by the clutch reservoir had failed so I bypassed it with some plastic tubing. Thank you KMT for pointing me to this thread: http://www.sccoa.com/forums/showthr...no-boost&highlight=89+sc+boost+valve+electric
ALSO, the title should be "Stays Open." I didn't know how the actuator functioned as well as I thought I did.
I need some pointers on where to look for issues in the vacuum system in an 89 SC. The supercharger hasn't worked for as long as I've been around (dad owned it before I was born and I don't ever remember it working) and since it's mine now I'm determined to find the fault and fix it. I bought an analogue test gauge and here's what I've done so far...
-I can open and shut the valve with some slight resistance, but I suppose that's just how stiff the actuator is.
-I took the hose off the actuator and did the finger-vac test on the single port it has. I can hold the actuator in the open position by first opening it then blocking the port, so that rules that out as a fault.
-I hooked the same line up to the test gauge and what I found doesn't seem right. The in-car gauge goes right to 20 In HG after 3 seconds of starting the car like it should, but the test gauge took it's sweet time crawling down to 20 In HG in the span of a minute. Since the line was presently connected to the test gauge and not the actuator this means the valve for the supercharger intake is stuck open, meaning I'd get boost. I blipped the throttle and surely enough I made some boost according to the internal gauge. The test gauge, however, didn't even twitch
This is about all the further I got since all the other lines are buried under the lower windshield plastic and I don't have a garage to work in yet for another month, so I'm mostly tinkering on it on sunny days. Going back to point 3 though is yes if I start the car cold and hammer it within that first minute it does get boost and tally-ho I am flying away, but as that minute goes by the valve opens more and more. I could just leave the system disconnected and always have boost, but I see people say that would lead to some combustion issues?
tl;dr version I have a vacuum leak, so my supercharger works but the valve gets pulled open after a minute of running. Where do I look?
ALSO, the title should be "Stays Open." I didn't know how the actuator functioned as well as I thought I did.
I need some pointers on where to look for issues in the vacuum system in an 89 SC. The supercharger hasn't worked for as long as I've been around (dad owned it before I was born and I don't ever remember it working) and since it's mine now I'm determined to find the fault and fix it. I bought an analogue test gauge and here's what I've done so far...
-I can open and shut the valve with some slight resistance, but I suppose that's just how stiff the actuator is.
-I took the hose off the actuator and did the finger-vac test on the single port it has. I can hold the actuator in the open position by first opening it then blocking the port, so that rules that out as a fault.
-I hooked the same line up to the test gauge and what I found doesn't seem right. The in-car gauge goes right to 20 In HG after 3 seconds of starting the car like it should, but the test gauge took it's sweet time crawling down to 20 In HG in the span of a minute. Since the line was presently connected to the test gauge and not the actuator this means the valve for the supercharger intake is stuck open, meaning I'd get boost. I blipped the throttle and surely enough I made some boost according to the internal gauge. The test gauge, however, didn't even twitch
This is about all the further I got since all the other lines are buried under the lower windshield plastic and I don't have a garage to work in yet for another month, so I'm mostly tinkering on it on sunny days. Going back to point 3 though is yes if I start the car cold and hammer it within that first minute it does get boost and tally-ho I am flying away, but as that minute goes by the valve opens more and more. I could just leave the system disconnected and always have boost, but I see people say that would lead to some combustion issues?
tl;dr version I have a vacuum leak, so my supercharger works but the valve gets pulled open after a minute of running. Where do I look?
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