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Yes, it's a 2-wire plug that activates the solenoid to actuate the vacuum and make it pump, otherwise it just free-wheels (hence the check valves), that's why I don't think it pulls too much HP. FWIU it only activates when the engine is cold, to help fire off the cat. The ECM doesn't even get any feed back if it's there or not so, no SES to worry about.Is there a wired plug that goes to the system?
You may be right on the threads. I'm thinking early TBI big block, which IIRC, are npt - but it's been years and years.1. The fittings in the exhaust manifold are very unlikely to be pipe thread. Mine are long gone, but similar systems used inverted-taper fittings, same as brake tubing but much larger.
2. The pump runs all the time. When cold (open loop) it pumps air into the exhaust manifolds as stated, to help "light off" the catalyst.
3. When the vehicle gets to "closed loop" operation, the diverter valve directs the air into the air cleaner, otherwise the added air would provide false "lean" operation of the O2 sensor because of pumping additional oxygen into the driver-side manifold.
4. The pump takes little power to run, if the thing works, leave it the hell alone.
5. Sure, it's possible to have a failed pump, or failed diverter valve, or failed check-valves. The AIR pump on my '88 K1500 failed at approx. 315,000 miles. I found another used-but-usable one to replace it with.