Hello all:
I may have found the reason for my engine running hot and giving me all sorts of trouble. Corrected a few things but looks like I have something wrong with the TAB and TAD solenoids. Here goes:
I've read over plenty of factory and some non-factory literature and can't figure out how these gizmos operate. Should be easy. Solenoid is either on or off allowing or not allowing vacuum to flow, thereby operating, or not, some component. I always have Thermactor air going upstream and after thoroughly looking at the setup on the car, an 86GT, its a mystery.
What do they do and when is my problem. If they are both off normally, how is any air flowing? According to my books, the TAB is closest to the fender with three wires. The other is TAD. Check. But the vacuum line routing is reversed. This would be my fault from a few years back. But if that's the case, how is air getting upstream? I pulled the old solenoids off to check them, plus a replacement. Both don't really hold vacuum but the shop manual says that is normal. Both solenoids work when tested. On both assemblies. I do need to clean the terminals but since I have no codes and vacuum seems fine, why the upstream air all the time?
I even checked the new diverter valve. It allows air to the downstream port without vacuum, upstream with vacuum.
If vacuum is reversed, then the bypass valve should be bypassing all air and nothing should flow to the diverter.
Quite confused obviously. A plain English description would be most welcome. I should just reverse the vacuum routing and see what happens but I want to be sure. Not really sure how the lines were switched.
Thanks much. Cheers.
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