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Engine Specific Info and Questions => IDI Engine => Topic started by: wolfsburgnut on September 18, 2006, 07:23:11 pm
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I was wondering if someone could explain the difference between the 1.6 and 1.9 pumps. I know that they are both Bosch VE pumps and that the 1.9 has some more gadgets on it, but what is the difference on the internals? As well what does it mean when people talk about a 9mm, 10mm or 12mm pump? Thanks.
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I believe that the internals are all the same. The 9mm, 10mm, 11mm is the diameter of the plunger head in the pump.
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As coke stated, the 9/10/12mm refers to the plunger diameter of the pump. The plunger diameter as well as the plunger stroke (camplate lift) determine the maximum quantity of fuel that can be injected per stroke. The 1.6 and 1.9 pumps both use a 9mm plunger. The 1.9 pump has greater camplate lift and can deliver more fuel per stroke.
Displacement alone is not the only reason for switching to a larger plunger. The larger plunger can deliver the same quantity of fuel to the injector in fewer degrees of crank rotation, getting the fuel in sooner and allowing more time for the fuel to mix and burn. All things being equal, pumps with larger plungers set to the same quantity per stroke tend to smoke less and produce more power.
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Thanks that definitely clears things up!
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Both older and newer style AAZ pumps had the 17mm shaft.
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Just clearing thing up,No worries :lol: