It should be running off of a ported vacuum switch shouldn't it?
Car has running issues
- Thread starter oldscutlasswagon
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yes and if it was on ported vacuum it shouldn't have any affect on the performance if the EGR is stuck closed or stuck open if you remove the vacuum source. If it is stuck open then the idle will be rough with or without vacuum and if it stuck closed it would have little but the same affect with or without the vacuum source. The EGR was set up with ported vacuum through a thermal switch so the EGR would not open til the engine was at operating temperature.
If the EGR was hooked up to the manifold vacuum with a properly functioning EGR it would be open nearly all the time and that would have a noticeable affect on the performance and if the manifold vacuum source was removed the performance would improve.
I am pretty sure it is connected to the thermo-vacuum switch. Either way its getting replaced, I think the egr itself was faulty and causing a slight vacuum leak.
where is the thermal switch getting it's vacuum from and is the switch working correctly?
I just looked and the thermo switch is getting vacuum from the bottom right-most port on the dualjet, which I believe is ported vacuum like it should be. All I know is that the car is driving a ton better since I plugged the line to the egr. Thermo switches aren't much so if that sounds suspect I could go ahead and order a new one.
the bottom ports on the carb are not ported.....when the engine is cold the thermal switch should be closed. Even if a part is not expensive I don't change it unless I know it's bad, I have plenty of other things I can waste my money on
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So which vacuum port is ported vacuum on a dual jet? I can buy a T fitting or two and hook it up to the correct port and see what happens.
The ported vacuum is above the throttle plates. If a carb is not working properly or has been rebuilt incorrectly I have seen manifold vacuum where it should be ported. You can check that with a vacuum gauge. I would suggest you buy a copy of Cliff Ruggles book on quadrajets. It'll pay for itself over and over.
So I have been looking at a few vacuum diagrams and it looks like my egr and a few other vacuum lines are criss-crossed between the thermo switch with 2 ports and the other one with more ports. Meaning ported vs manifold. If anyone can verify a Google Image that's correct for a CA car I can start investing in feet of hose and fix everything. Then see what happens after that.
Most of the diagrams I see don't seem correct as my car came from the factory without a vacuum advance distributor. I also noticed they don't show a vac delay valve between vacuum source and egr which I believe is supposed to be there. I have no problem purchasing a manual if I know it has correct info, it's just frustrating that CA cars had different smog setups/components than other states. Manuals usually don't make this distinction for this era olds.
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