Originally Posted by twtcad (Post 6003363)

ron.....adding the wires are only for a switch to turn the mod on/off. It is not necessary and is not recommended on the site with the pics from what I read. As far as resistor direction, I'm not sure......if you do not get an answer here, I would ask the supplier if it goes both ways........LOL

Originally Posted by mustang_gt_350 (Post 5360167)

...Ok, I spent some time with some help of a friend playing with the IDM and a scope today. From the way it looks the PCM is sending 2 signals per injection event to the IDM.
I also Measured the output voltage while runing and was very shocked on how low the actaul output to the injectors are compared to what i have read the working voltage is. My stock 120 IDM was only putting out 66 volts to the injector Noting near the often qouted 120 volts...

Originally Posted by ernesteugene (Post 5360266)

...I read that the IDM has it's own little onboard computer/microprocessor, and that the PCM sends the IDM digital words which instruct the on and off time for each injector pulse. I think the two signals you see are the one word for on and the other word for off. Also, the off pulse is reverse polarity to drive the solenoid in the off direction.

Originally Posted by ernesteugene (Post 5366306)

...The PCM programming controls the Injection Time IT*=crank degrees, and the injection Pulse Width, PW*=crank degrees. These parameters control the timing and the amount of fuel injected, and this in turn tailors the peak combustion pressures in the vicinity of TDC, and this is what determines the cylinder MEP and resulting HP.

To program for maximum HP, you want to control the IT* and PW* to maximize MEP at each RPM. Of course the Ford PCM programming has to worry about other things as well, including emissions, MPG, and reliability.

At 3000 RPM, for example, each crank deg is 55.55 usec. At 3000 RPM, an impulse (zero time width) injection at 30* BTDC, is followed by a 20* ignition delay, then a 5* delay as pressure rises to a maximum, so maximum occurs at 5* BTDC. The actual pulse width, PW, is about 555.5 usec, so that fuel is injected over a 10 deg interval of crank degs. Therefore, fuel injection occurs from 30* to 20* BTDC, then 10* to 0* BTDC for initiation of burn, and maximum pressure at 5* BTDC to 5* ATDC, and this gives maximum cylinder MEP and thus HP.

Originally Posted by ron's power stroke (Post 6003338)

i see the resister has a brown stipe on one end..if i did this just like the pic...witch way does the brown stipe on the resister go??? or does it do its job ether way?? i know diods only work one way..im not great with electronics so please excuse so many questions...

Originally Posted by TchTchr (Post 6003772)

It doesn't matter which direction you solder the resister. Current through them flows the same. The stripes on them indicate how much resistance they provide.

Originally Posted by ron's power stroke

All you need to do, is remove the original resistor, and solder in the correct resistor as listed
above for your model IDM. (Should be a sticker that lists the model near the connector).
In the pics I have, you would solder to the same place on the board that the green and yellow
wires are soldered. You shouldnt use wires or switches.

Originally Posted by cookie88 (Post 6003835)

Ron. I just added some pics to my galley covering this very thing. Dave is on his way over here now, so by the end of the evening this gallery should be a fairly inclusive step by step how to....that's what I'm hoping for anyways.

2001 Ford F250 4x4 - IDM mod

Originally Posted by ron's power stroke

whats this Gene is talking about??

Originally Posted by nlemerise (Post 6004538)

Might I suggest a bulk purchase of both the resistors? I just priced five resistors delivered....$1.09 for the resistors, $5.00 handling, $2.32 postage for a total cost of $8.41 or $1.68 each.

I then priced 200 of the resistors...$16.68 for the resistors, $5.00 handling, $2.32 postage for a total cost of $24.00 or $0.12 each

EDIT: I just found out that the total cost to me would be almost exactly $40.00 (for 200 of each resistor)...no handling charges!!! So that makes them $0.10 each...5 mailed to you for $1.00, and that includes postage.

I'd be willing to do it if there is enough interest to make it worth our while...Any interest?