Does anyone have a good, very detailed vacuum diagram for a 1990 sunbird Turbo w/ auto? When I bought the car there were quite a few things unplugged/ missing/ plugged off. So when I rebuilt it I basically did some common sense stuff and it runs pretty good. I'm using a manual boost controller. I've got pretty crappy vacuum ~10-12 in/mg. according to the stock boost gauge. The cruise does not work, and I have a rough idle (still). Since I'm going to be tuning with Craig moates autoprom or ostrich, I need to have the factory boost controller operational. So I need to get the vacuum system up and running correctly. I've looked at the Mitchell diagrams, and they don't include boost controll or emissions/charcoal canisters. Basically just the MAP, fuel pressure regulator and brake booster. I need more detail than that... Anybody?
1990 Pontiac Sunbird GT turbo
-TGP turbo
-DSM SMIC turned TMIC
-Injectors
I'll scan in the diagram tonight when I get home from work...
Thanks, you're the man!
1990 Pontiac Sunbird GT turbo
-TGP turbo
-DSM SMIC turned TMIC
-Injectors
Awesome! I've been looking for this also. thx!
The only question I have left now is that the boost solenoid that I have has 1 line in and 2 out... Where does the other one go?
1990 Pontiac Sunbird GT turbo
-TGP turbo
-DSM SMIC turned TMIC
-Injectors
EGR is contorlled by a elec vac regulator valve with a one way check valve. I know that an egr recirculates exhaust into the intake to lower emissions, and lower burn temperatures in the cylinder. Under what conditions does the egr open. EG (at idle, partial load, no boost, only when on boost, full throttle). I'm thinking this may also have to do with my strange idle, because my egr is not hooked up to my electric vac reg. vlv. Any info on egrs?
1990 Pontiac Sunbird GT turbo
-TGP turbo
-DSM SMIC turned TMIC
-Injectors
Never mind I have once again answered my own question, but will answer it here just incase anyone is wondering.
Definition: The EGR valve is the main emissions control component in the exhaust gas recirculation system. The valve is located on the intake manifold, and opens a small passageway between the exhaust and intake manifold to allow a metered amount of exhaust to flow back into the engine. This reduces combustion temperatures and helps control the formation of oxides of nitrogen. The EGR valve is opened by the application of vacuum to its control diaphragm. Some also require a certain amount of exhaust back pressure before they'll open. On newer vehicles, the valve is electronic and uses one or more solenoids or a small stepper motor. The valve should remain closed while the engine is cold and at idle. It should only open once the engine has warmed up and is running at part-throttle. If the valve sticks shut (or is disconnected), NOX emissions will soar and detonation will often result (See Detonation and Spark Knock). If it sticks in the open position or fails to close all the way, it acts like a vacuum leak resulting in a rough idle, hesitation and possible stalling.
So basically what I"m getting out of that is that the elec vac reg. vlv is the egr control solenoid and supply of vaccuum. So that says that the egr is only open at part throttle, no boost since there is a one way check valve... This could explain the bird running good at first start up then with the bad idle after running for a minute or so. It's amazing how important something is, that actually makes an engine run less efficiently in the name of emissions.
1990 Pontiac Sunbird GT turbo
-TGP turbo
-DSM SMIC turned TMIC
-Injectors
When you start tuning you will be able to disable the EGR valve function without any loss in performance or mileage, and likely no change in emissions. If you suspect the EGR opening at idle simply disconnect the valve.
If the vacuum hose between the EGR solenoid and the throttle body is connected correctly you should only have vacuum when the throttle is not closed. The throttle plate opens and uncovers the port which is connected to the EGR hose, thereby allowing vacuum to the EGR. This is called "ported" vacuum. The EGR solenoid is like the boost control solenoid. When the solenoid is off, it blocks the vacuum signal from the TB and connects the EGR port to the vent port to release any vacuum in the EGR valve diaphragm.
Keep plugging away!
-->Slow
Well, the EGR is unplugged and it's still running goofy like that. I guess I'm going to have to dig some more...
1990 Pontiac Sunbird GT turbo
-TGP turbo
-DSM SMIC turned TMIC
-Injectors
