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Old 06-10-2013, 01:04 PM   #6 (permalink)
t vago
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I could not find any potentiometers smaller than 5k ohms at Radio Shack, and was not willing to wait around for Digi-Key/Mouser to ship me one.

So, I put a 1-pin weatherpack connector on the wire extension I installed yesterday, then installed a 1-pin weatherpack jumper with a 220 ohm resistor on it. Now, I can very quickly switch between stock and added resistance. Hopefully, the 220 ohm resistor will be small enough to be acceptable by the engine computer. If not, I might as well go to plan B above, because I just don't see that it's possible to get any sort of meaningful increase with anything smaller than 220 ohms.

I've added the below table in an attempt to illustrate the # increase in EGR valve opening with the added resistance. "Stock" is what the engine computer would get if it commanded the EGR valve open at a certain percentage, without the added resistance in-line with the position sensor. With the feedback from the valve position sensor with the added in-line resistance, the EGR valve would open to the "modified" percentage value.

% EGR Opening, Stock and with 220 ohm resistor added
StockModified
0.00.0
5.05.4
10.010.8
15.016.2
20.021.6
25.027.0
30.032.5
35.037.9
40.043.3
45.048.7
50.054.1
55.059.5
60.064.9
65.070.3
70.075.7
75.081.1
80.086.6
85.092.0
90.097.4
95.0100.0
100.0100.0
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