So my truck keeps almost dying then comes to live again. Always while shifting from 1st to 2nd like on onramps and such. While doing the 3 key cycle it brings up P1693 code, but when I scan it, it says there is no codes. Any ideas what or where to look. The truck has 449,000 on it, we've replaced the injection pump once, head gasket once, routine 3k maintance. Thanks!

 

P1693 means there is a code stored in the computer.

Does it always act up at a certain throttle position?

 

Not always no. Just seem to notice it more I think when accelerating the 1-2 shift.

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There's always a big puff of blue smoke when it does it also.

 

Hows your fuel pressure?

Luke

 

my 01 was doing the same thing i also had a transducer prob on top of 1693 but anyway 1693 was a fuel calibration code for me i spliced on a new harness for my map sensor and replaced the map sensor itself and prob solved, i created this prob in my truck by wiring a smoke switch to a diablo power puck, after fixing i have not messed with a smoke switch and now i have a smarty and diablo and my truck never bucks, or serges,

your truck is saposed to defuel during shifts to make it easier on the trans thats prob y your feeling it the most between 1-2 my truck was the same,

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your transfer pump may also be going out so during the calibratio of the shift the pump may be loosing pressure and if thats the case its sucking the life out of your injection pump**