What specifically is the function of the air pump on an 1988 928?

 

To pump air

Actually it is used to pump air in to the Cats to reduce emissions.

 

John,
Thanks, I wanted to verify I wasnt altering another function other than pumping air into the cat.
I plan to use a bolt on x style test pipe set up for a DE event, then switched back to the cat for state inspection / normal use.
Just wanted to be sure it would not create a problem in some other function during the time it was off and driving to / from a track.

 

Tom-

Not only compliance with the emissions, but the Cats may impact your performance.

On my 87 S4, with the Cat removed yielded another 30 HP.

YMMV-

 

Where exactly the airpump is located?
P.O. sold me the car with it removed and I want to know where on the engine bay it goes should I install it again.

 

Passenger side, above the air conditioner compressor.

Greg

 

On my 79 928 the air pump ceased up, the previous ovner removed the belt and thereby removed the cooling from the fan connected to the above mentioned pump.

At my Porsche/shop dealer they told me it was a "not needed" item. They dismounted it and instelled a Japanese(????)modification. A bracket with a spinning wheel. Fan is working fine and no problems with overheating.

I do not have a cat.

Geir.

"I have found that sufficient amounts of alckohol produces the same effects as drunkeness"

 

My pump locked-up and I replaced it with a rebuilt unit from 928 International (for a very fair price). Without it, I KNOW the car would fail emissions.

 

I'm not sure about this at all !
Euro models (mine included) don't have cats so why do they all have air pumps ???

 

Linus - Air Pumps coincide with catalytic convertors. Their two purposes in life is to reduce emissions and to reduce horsepower. Even though I have a Euro Model, we still need cats or we cannot register with the DMV.

I will say this, if you live in a City such as LA - you would be glad the cats are in place. Man is it thick there.

Kudos

 

The euro's pump air to further burn any raw unburned gas in the hot exhaust system.