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  • air pumps

    Topic originally created by dbone on September 14, 2005 3:41 PM and viewed 1994 times in the old forum.

  • #2
    Originally posted by dbone on September 14, 2005 3:41 PM
    Another question arising from my almost completed project. My mechanic cleaned out the injectors just above the headers. He was saying that he air pump, which i thought was only on US cars, supplied air through these injectors and help keep the exhaust valves just a bit cooler. The subject came up when I told him that the pump started making noises so I disconnected the ground wire at that green box to disable the pump from operating. I had already had that pump rebuild. I just assumed that the bearings were shot again and it really did not do anything to the performance. I was always under the impression, that the air pump was an attempt to keep the feds happy with the emmissions. Is there any real reason to keep this pump operational aside from the usually smog rules that may come into play. California does not require these cars to be smog tested any longer. dave


    • #3
      Originally posted by pauldridge on September 23, 2005 12:53 PM
      Dave.... I'd be real interested to find out those comments also. All my understanding on these exhaust injection systems is that it makes the valves run HOTTER, by inducing additional combustion. My air pump pretty much disintegrated itself, so I removed the belt entirely, so far no adverse affects, but now I'm concerned about possible long-term effects? Looking for guidance from others


      • #4
        Originally posted by Zanny1 on September 24, 2005 11:57 PM
        I removed the air pump from my euro C4 sn 15693. From a mechanical standpoint, there´s no way the air pump will cool the valves. The intent was to increase exhaust gas temparature to promote more complete combustion in the waste stream. Since the euro cars were not fitted with one, it looks correct having it removed. I did have to replace the right side air filter box, as it had a hole chopped in the front of it to make room for the air pump.


        • #5
          Originally posted by Aaron on October 14, 2005 8:44 AM
          My experience from the past regarding the Air Pump - On chevy’s the air pump tended to accelerate the deterioration of the exhaust valves. It was indeed an attempt to “burn up” all those remaining bad gasses that were not consumed in the combustion - remember the combustion ratio and timing has been reduced to solve – I think it is NO, which means that the hydrocarbons are higher than they would have been. So by adding air to the exhaust, remaining and now excessive hydrocarbons were in fact reduced. All this is nicely explained in the Bosch Fuel injection book, which I haven’t looked at since working on that TR problem several years ago. Not having a functioning air pump will not hurt your engine and may extend your exhaust valve life. My car lost its pump prior to my ownership and at some point I need to track one down for originality, but only for originality. (I have pushed the timing back up (15 degrees initial advance and 35 total advance at 3300 RPM) so my hydrocarbons should be down some. The nitrogen Oxides are probably above standard.) Because of age, C4s are exempt in CA, which is good from my perspective. Generally speaking I would not inflict my engine with an operational unit My 2 bits – Aaron