Does anyone know the number of teeth on the flywheel ring gear of the 6.5? On the same question do they differ in certain years?(Probably not but gotta ask) The reason why I ask this just to let you know is one other thing that I have had in the back of my brain working on(That just re-surfaced) is a replacement for the optic sensor. If i'm lucky the number of teeth will be 128 which is 1/4 of the 512 needed for the Hi-res on the optic sensor. Mounting 2 magnetic (hall-effect, similar to crankshaft sensor) pickups right over these teeth and then running them like a quadrupole encoder (Basicalliy mounting them one on one off tooth then taking the pulses and edges and converts them to single pulses, (on-off= pulse,on-on =pulse,off-on=pulse,off-off=pulse= four accurate pulses from two pickups. 128x4 =512) would effectively replace the optic sensor that is in the IP.

Problems: Still need to address timing stepper motor for advancement.
Possible solutions: Digital advance and retard via PIC or Atmel(microcontroller-This is my preferred method as no additional mounting or apparatus is needed. Optic bump could be adjusted easily and even "on the fly". This however will take more brain cell function as my micro programming is rusty).
Or physically mount existing or other stepper to new sensor.(Easier on brain cells but harder labor-wise)
If the flywheel scenerio does not play out I could use a micro to add or subtract pulses or easier just mount my own wheel on the damper or other places?
Why would anyone want to do this? Well it would be easier to get at. It would not be affected by diesel fuel. Would be unaffected by color of fuel or temp.(People running "alternative fuels" motor oil, heated WVO,etc.. :) )
Cheaper to replace. It would not be made by Stanadyne (Biggest reason to change it)

I'm at work at the moment but gonna do some probing on the PMD later. Thanks to BCbogger and others I will know what to look for and expect (saves time)
Just had this thought in my head so I had to ask! If I have been down this road and asked someone this before, sorry.
:)

The smaller 350 flywheel is 153 teeth, iirc the 454 was larger at 168 teeth, so no-go, mdh..............

The smaller 350 flywheel is 153 teeth, iirc the 454 was larger at 168 teeth, so no-go, mdh..............
Thanks! I could still do it since it is over 128 but it would take more work programming wise than it is probably worth! When I get to it i'll probably just add a wheel and be done with it!
Thanks again gmctd!

The VSSB may be a good choice for frequency division, since it is infinitely programmable, with several outputs.

Well - "infinitely" is a big word hinting at an even bigger concept, so maybe "multiply" progarammable is more correcter.

The VSSB may be a good choice for frequency division, since it is infinitely programmable, with several outputs.

Well - "infinitely" is a big word hinting at an even bigger concept, so maybe "multiply" progarammable is more correcter.

Ah! Never thought of that! How many pulses does it produce, and is it directly related to crankshaft timing? The minimum derivitive of 512 I could use is 128 as any more than 4 would not be a "true" timing. Other wise I could multiply the 8 pulses from the crankshaft signal. I thought of using this then having a micro pulse 64 pulses per each 8 (512) The trouble is advancing those pulses as the engine rpm changes. I would always be one 64bit pulse off. I thought of ways to take care of this electronically but it becomes complicated to make it accurate. (I like simple to a point)

If you have or know of info on the VSSB let me know. I need to look at this anyway as my speedo is about 10mph off!

Will do, shortly - I'm Dodgin', rat now (see my sig)...................

Hate to put a damper on your parade, nice info by the way. The optic sensor is there more for advance control. It monitors the relationship between the cam ring and the drive shaft. Flywheel mount cannot do that. That is one of the DS pumps greatest achievements other than keeping fuel shops busy:) What it does is monitor the advance for the computer among other things. Computer reads this info and transmits a signal to the stepper motor. Stepper motor responds and optic reports the progress in just nanoseconds. Quite remarkable and very, very acurate.

I've discussed adjustable timing here: http://dieselplace.com/forum/showthread.php?t=23239&highlight=crank+trigger

Hmmmm.....is this a new position, DP?

I seem to remember........ someone........ encouraging QM to do something similar.

Lessee.......who was that masked man, anyway? ):h

Change the crank sensor. Never encouraged a optic sensor. Now if we put a control on the stepper motor and fooled the computer. Nope to complicated. Crank sensor on flywheel is do-able. Smart maybe not. Ain't been right since my wreck Fri. Pics to follow soon as can see straight again/

I was thinkin' you been keepin' kinda scarce, fer a bit, there........hope ever'thin's awrite - sincerely.

Hate to put a damper on your parade, nice info by the way. The optic sensor is there more for advance control. It monitors the relationship between the cam ring and the drive shaft. Flywheel mount cannot do that. That is one of the DS pumps greatest achievements other than keeping fuel shops busy:) What it does is monitor the advance for the computer among other things. Computer reads this info and transmits a signal to the stepper motor. Stepper motor responds and optic reports the progress in just nanoseconds. Quite remarkable and very, very acurate.

I've discussed adjustable timing here: http://dieselplace.com/forum/showthread.php?t=23239&highlight=crank+trigger

So it looks as if I would have to mount it to the backside of the IP via the oil filler tube maybe? (My first idea,Looks do-able?) Gotta be a way to mount to the cam ring. Once that is done the rest should be straight forward electronically.
One thing that I wonder though! If it is reading the relationship between the cam ring and the crankshaft, I know it is not getting a high-res signal for crankshaft as I thought the crankshaft sensor is only 8 pulse not 512 like the in the IP.(And its low-res 8) Is it just reading how far off the 512 count is from the tdc of each crank pulse and then adjust stepper from there?
Anyway you look at it though just re-producing the signal from the same area of pickup (cam ring) should do it. I just don't like the fact that they immersed a optic encoder(2) in diesel fuel! It really makes no sense!(at least to me!)

I read QM's statement:
"Well, if you reprogrammed the limp mode to advance the timing you could run the truck on the crank trigger alone and not worry about the optical" "
That would be the simplest method.

How does the 93 & earlier mechanical IP's deal with this minute on the fly advancement or do they? Are they just not as refined? If so mounting to the crank may not be as accurate as before but would it be as good as the old mechanical setup? If so that might be good enough for most just not emmissions-wise!

Advance cam on the throttle shaft moves a lever which gates a valve in the IP which allows housing pressure to move a piston connected to the camring.

Optic Sensor has two - count 'em, two - optic sensors : 512 slot hi-res and 8 slot lo-res, or cam, which lets PCM compare IP shaft TDC referenced to crankshaft TDC position in degrees.

Advance cam on the throttle shaft moves a lever which gates a valve in the IP which allows housing pressure to move a piston connected to the camring.
Thanks!

Optic Sensor has two - count 'em, two - optic sensors : 512 slot hi-res and 8 slot lo-res, or cam, which lets PCM compare IP shaft TDC referenced to crankshaft TDC position in degrees.
Yes, I know that there are two on the IP and they are physically on the same encoder wheel (512 on top and 8 slots below located on same wheel I believe?) which means they could not vary from each other. I thought that you meant they were referencing the difference between the IP shaft and crankshaft physically. (Meaning reading from crank, reading from cam, check difference, adjust)

I just read your post on "Injection Pump principles" http://dieselplace.com/forum/showthread.php?t=10790And I am more enlightened once again! That should be a sticky! I'll come up with more questions though!

Not my thread, my friend, just a contributing postee.

You might check my threads and posts for TDC Offset considerations, tho, for more on the electronic aspect.

And that is how it works - PCM reads crank TDC, reads IP Cam TDC, compares actual position by 512 hi-res count output, makes required adjustment(s) to maintain timing accuracy.

Not my thread, my friend, just a contributing postee.

You might check my threads and posts for TDC Offset considerations, tho, for more on the electronic aspect.

And that is how it works - PCM reads crank TDC, reads IP Cam TDC, compares actual position by 512 hi-res count output, makes required adjustment(s) to maintain timing accuracy.

Thanks again! Will do more on the reading. The more I understand the whole picture the easier it is on me! I'm getting there! (I Think?)

Back to confusion. The High-Res (512) and Low-Res(8) tracks are on the same exact wheel they cannot move. The optic sensors for both of these tracks are mounted in the same housing and move together(One stepper) Cam, crankshaft,IP shaft & flywheel are tied together by timing chain, gear,? TDC on one is TDC on the others. (eventually TDC on all will line up)Yes they could turn at different speeds and would require different amount of reference points or spacing to get the 512 or 8 pulses coming out at the same time as the encoder wheel in th IP. But if you mount a encoder and sensor on anyone of these points(Cam, crankshaft & flywheel) it should turn the same and could be utilized the same as mounting in the IP.
You could digitally make up the difference in pulses to compensate for encoder wheel size. If I had 8 marks on a 2 inch wheel geared to a 4 inch wheel. The 4 inch wheel would need 16 marks to pulse at the same speed.
I would need 2 long marks at exactly half of the 4 inch wheel to replicate the one on the smaller wheel. Or I could put 8 marks and electronically multiply it!
I guess what i'm thinking is if the cam, crankshaft,IP shaft & flywheel are tied together then picking up from any of these points for reference should not matter. Size of encoder wheel and rotation speed would be the only concern.

You need to get an old pump and take it apart. The encoder is fixed to the camring. the camring only rotates about 10 degrees which is 20 crank degrees. This is your advance. Encoder relays advance back to computer. Computer says I want 5 degrees. Stepper motor moves the advance piston which moves the camring. Encoder relays info back and computer adjusts again and again till desired 5 degrees is achieved. Simple and extremely fast. That's why it is one of the best things the DS pump is known for, even if it does fail sometimes.

You need to get an old pump and take it apart. The encoder is fixed to the camring. the camring only rotates about 10 degrees which is 20 crank degrees. This is your advance. Encoder relays advance back to computer. Computer says I want 5 degrees. Stepper motor moves the advance piston which moves the camring. Encoder relays info back and computer adjusts again and again till desired 5 degrees is achieved. Simple and extremely fast. That's why it is one of the best things the DS pump is known for, even if it does fail sometimes.

I was under the impression that the stepper moved the optic sensor(s)itself and the encoder wheel was fixed (at least in relation to crank movement)? What I gather from what you say is the encoder wheel is fixed to the cam ring and the cam ring moves via stepper, and the optic sensor(s) don't move? Cam ring itself is not in a fixed position in relationship to the crankshaft? I need to get me a old IP to tear apart and study.

I did scope my PMD today though and begun mapping out exactly what it is doing! (I hope) So far so good.

Stepper motor moves advance piston, advance piston rotates the camring a maximum of 10 degrees. Encoder if fixed to camring. Datatrac disc rotates with pump drive shaft and runs half engine speed.

http://flashoffroad.com/Diesel/injectionpump/injectionpump.htm

Stepper motor moves advance piston, advance piston rotates the camring a maximum of 10 degrees. Encoder if fixed to camring. Datatrac disc rotates with pump drive shaft and runs half engine speed.

http://flashoffroad.com/Diesel/injectionpump/injectionpump.htm

O.K. So if I mount a encoder externally I will have to advance it either electronically or mechanically(another stepper) by sensing the PCM commands to the existing stepper. If done right it should be accurate.
Hope i'm not driving you crazy!:)