Since physically rotating the IP without running a learn diagnostic will not advance the injection pulse due to the optical sensor compensating for the adjustment. Is it possible and/or has anyone tried to adjust the position of the optical sensor on the IP to advance injection. Factory timing is @-.25 thru -.75 with people claiming advantages by getting as close to –2.0 as they can without going over. Apparently running past –2.0 trips an engine code. If the optical sensor could be moved it seems like the timing could be moved to whatever you desired without the computer knowing you had changed from stock.

Are we talking timing advance or TDC offset. When I rotated the IP on the stepper motor it took it from 3.5 deg. to 7.8 deg. on my scanners display but without tech functions on my computer, I can't adjust tdc offset from .25 to 2.0.

So it can be advanced.

Dont confuse TDC Offset with Base Timing. TDC offset is set in the PCM with a TECH2 scanner and that sets the -.25 to -.75 offset that the computer uses to calcualate timing. Base Timing is set with an aftermarket (Snap-On etc..) scanner and is just to set the static timing of the pump within the operational limits of the pump. And yes, the optic sensor can be advanced and will increase fuel delivery and advance timing simultaneously, but can have negative effects if taken too far. I don't know exactly what your Heath chip has done for you, but apparently its not enough.


In fact the optic sensor advance (or retard depending on how you look at it) is arguably a Better way to achieve advanced timing and more power out of you 6.5 (and I will argue that). First of all, its free, second of all keeps all you OEM safeguards in tact, third, I did it to mine and it freaking flys and still runs cooler and gets better mileage than ever!Edited by: Texas Diesel Guy

Hey TDG


Sounds great


So how did you do it ?


or please show the link to how to do it.


Please

TDC offset can ALSO be set with a Snap-On scanner in OBDII trucks as well as base timing, actually it's done with proper sequence of key on, key off and APP to the floor to initiate the learn. A little more complex than with the T2 but it can be done, clue though is OBDII, I don't think it works this way on OBD1, PM me if interested on how to do it.