Post Recall AIR system vaccum lines
07-17-2006, 02:40 PM
#1
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Post Recall AIR system vaccum lines
The Vac lines that go to the AIR system module... what are they used for? We removed the whole Air system after a header install and am really more curious than anything.
Also, my vaccum lines were messed from a rebuild years ago on the engine. The EVAP solenoid was hooked up to the AIR vaccume line and the evap hose in the fuel line bundle was just sitting in there unconnected. Any ideas what effects this might have had on my car long/short term?
Also, my vaccum lines were messed from a rebuild years ago on the engine. The EVAP solenoid was hooked up to the AIR vaccume line and the evap hose in the fuel line bundle was just sitting in there unconnected. Any ideas what effects this might have had on my car long/short term?
07-17-2006, 03:55 PM
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Re: Post Recall AIR system vaccum lines
Just looking at the recall components diagram on Shoebox's Tech Pages:
http://shbox.com/1/air_pump_recall.jpg
Appears they were trying to solve the problem of exhaust gasses leaking backward out of the manifold check valves, and finding their way back to the AIR pump when it wasn't running. The "shutoff valve" appears to be vacuum operated, and would prevent backflow to the AIR pump. The recall problem addressed excessive current draw on the AIR pump as well, and the electrical draw was often increased by corrosion in the AIR pump due to the moisture condensing out of the exhaust gasses in the AIR pump and corroding it.
Just a guess....
Not having the EVAP canister line connected to anything probably wouldn't affect the engine too much. The PCM is expecting fuel vapor rich air mix when its purging the EVAP canister. It would not get to the intake manifold if the line from the canister is not connected. The canister would saturate with fuel vapor, and eventually become useless, contributing to a fuel smell at the dirvers rear fender.
As far as the EVAP solenoid being connected to the connection for the AIR vacuum line (instead of to the EVAP canister purge line), you'd be pulling a small vacuum on the solenoid whenever the PCM opened the EVAP purge solenoid. Instead of pulling fuel vapor from the canister into the vacuum connection on the side of the throttle body, you'd have the vacuum on the side of the throttle body fighting with the vacuum in the intake manifold. The pressure would probably be the same on both sides of the solenoid, unless the vacuum connection on the side of the TB was "ported vacuum" and in some way variable based on throttle blade position.
I wouldn't worry about any long term effects.
http://shbox.com/1/air_pump_recall.jpg
Appears they were trying to solve the problem of exhaust gasses leaking backward out of the manifold check valves, and finding their way back to the AIR pump when it wasn't running. The "shutoff valve" appears to be vacuum operated, and would prevent backflow to the AIR pump. The recall problem addressed excessive current draw on the AIR pump as well, and the electrical draw was often increased by corrosion in the AIR pump due to the moisture condensing out of the exhaust gasses in the AIR pump and corroding it.
Just a guess....
Not having the EVAP canister line connected to anything probably wouldn't affect the engine too much. The PCM is expecting fuel vapor rich air mix when its purging the EVAP canister. It would not get to the intake manifold if the line from the canister is not connected. The canister would saturate with fuel vapor, and eventually become useless, contributing to a fuel smell at the dirvers rear fender.
As far as the EVAP solenoid being connected to the connection for the AIR vacuum line (instead of to the EVAP canister purge line), you'd be pulling a small vacuum on the solenoid whenever the PCM opened the EVAP purge solenoid. Instead of pulling fuel vapor from the canister into the vacuum connection on the side of the throttle body, you'd have the vacuum on the side of the throttle body fighting with the vacuum in the intake manifold. The pressure would probably be the same on both sides of the solenoid, unless the vacuum connection on the side of the TB was "ported vacuum" and in some way variable based on throttle blade position.
I wouldn't worry about any long term effects.
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