Air Pump ?
Air Pump ?
07-09-06, 08:45 AM
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Originally Posted by dgeesaman
Wikipedia is great. You can get anything on there.
07-09-06, 10:55 AM
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The air pump sends "air" to the pre-cat thorugh the ACV valve/exhaust manifold and to the main cat at various operating conditions, such as under 3K (2.5K with PFC) deceleration and some low RPM operation. The air help oxidize the exhaust gases, reducing emission.
Many people find that the removal of the pre-cat, while retaining the main cat still allows for the passing of a standard smog test. However, need to remember, that the pre-cat is still part of the total emission system and the air pump contibution to it does help in emission testing. Even after the air pump shuts off (beyond a preset RPM) both cats continue to be working in a non-catalyzing mode.
Since the air pump injects air into the exhaust manifold just before the O2 sensor, the engine management (ECU) is expecting this airstream. Removing the airpump will upset the O2 readings and often result in erratic idle for the FD.
Albert
Many people find that the removal of the pre-cat, while retaining the main cat still allows for the passing of a standard smog test. However, need to remember, that the pre-cat is still part of the total emission system and the air pump contibution to it does help in emission testing. Even after the air pump shuts off (beyond a preset RPM) both cats continue to be working in a non-catalyzing mode.
Since the air pump injects air into the exhaust manifold just before the O2 sensor, the engine management (ECU) is expecting this airstream. Removing the airpump will upset the O2 readings and often result in erratic idle for the FD.
Albert
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07-09-06, 11:09 AM
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Originally Posted by DrunkenBowler
How do you fix this? I have that problem.
I, for one, have retained my air pump. Others, who removed them, report that it is possible to tune the fuel map at idle speeds, if you have a PFC.
I tried to lean out my idle after raising my fuel pressure, disconnected the air pump and tried to change the fuel map for a leaner idle. It really did not work the idle remained rough throughout the tuning attemp while the pump was disconnected. I suspect that I may have been loading up the plugs while doing the tuning.
Albert
07-09-06, 11:30 AM
#9
I have removed the smog pump on around 12 FD's and have never had it change the idle. I say if you dont need it for smog get rid of it. If you remove the whole system you it can be a easy 20-25 pounds.
And I dont mean for this to turn into another yes it will change the idle, no it wont thread. I am just posting that I have done this to at least a dozen FD's that came form different states and have never once had a problem.
And I dont mean for this to turn into another yes it will change the idle, no it wont thread. I am just posting that I have done this to at least a dozen FD's that came form different states and have never once had a problem.
07-28-06, 02:03 AM
#10
Senior Member
Can I keep the airpump while removing the ACV to pass smog? The last time I passed smog, I had a faulty split air bypass solenoid (which is connected to the ACV), so that made me wonder... Could I bypass the ACV and make a direct airpump line from the smog pump to the cat while still passing smog? Anyone know?
Last edited by FDeez; 07-28-06 at 02:27 AM.
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